View E90901_1674468.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

?? ????????? elmos semiconductor a g application note qm-no.: 03an0801e.0 1 e9 09.01 1 designing systems with halios ? switch general description features applications the halios? principle highly improves sensitivity and robustness against disturbances of sensor systems. therefore it is possible to realize, e.g. touch or approach detection systems based on a capacitive working principle even in metal shielded environment or optical input devices under high ambient light con - ditions. the e909.01 is an op tical switch w hich is able to suppress the in?uence of ambient light by using the halios ? workin g principle. the device detects the rapprochement of objects and additionally indicat es when the object touches the surface. these functions are available on the device pins prox and touch. fu rther, the corresponding measurement values can be readout via spi interface. elmos recommands the integrated optical module tcnd 3000 for optimized optical sensitivity. ? two outputs for proximity and touch function ? spi interface for measurement data ? selfcalibration capability ? operational up to 200 klux ambient light ? package sop 16 or tssop 16 ? supply voltage: 3.3 v to 5.0 v ? C 40 c to + 85 c operating temperature ? waterproof switches ? switch for anti-septic environment ? switch with background lighting function ? proximity sensing ? optical key pad array this application note provides information about how to design systems with the halios?switch e909.01 and gives examples of schematics and appropriate surface materials. scope ? control filter demod. spi avdd dvdd 100f sck mosi vdd touch a / ldb touch b / miso en_spi 500 swto prox syi syo avss dvss dvdd tin ledc leds 500 100k vdd vdd vdd 10 100f 200pf vdd tcnd3000 leds ir-emitter leds (transmitter) ir-emitter ledc (compensation) photodiode gnd tin ledc translucent surface d s_obj d s_surf d s = d s_int + d s_surf + d s_obj d s_int d c /39
e9 09.01 2 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 system comparison parameter mechanical capacitive piezo-electric resistive halios?(optical) integration under solid surface no yes yes no yes possible distance between actuator and surface 0 mm positive ?t necessary several mms 0 mm positive ?t necessary 0 mm positive ?t necessary 0-50 mm or more depending on the setup possibility to change arrangement of elements (e.g. exchangeability of surface) huge effort medium effort huge effort medium effort exremely low effort printability of surface yes yes yes restricted all ir transparent colors and surface possible resistance against mechanical wear no yes yes no yes operation under humid conditions restricted no yes restricted yes resistance against chemicals and liquids restricted depending on sur - face depending on sur - face no yes possibility of far distance detection no no no no yes possibility to differ - entiate between certain gestures no restricted no restricted yes resistance against in?uences by ageing no yes yes no yes resistance against in?uences by tem - perature changes yes yes yes restricted tempera - ture range yes required operation force certain force neces - sary touch of surface suf - ?cient certain force neces - sary certain force neces - sary light touch of sur - face, even gesture recog - nition possibility to change functionality via sw no no no no yes / 39
3 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 sop 16 package outline and description pin description figure: pin-out e909.01 pin nr. name type 1) function 1 avdd a i analogue supply 2 tin a i transimpedance ampli?er input 3 avss a g analogue ground 4 ledc a o output compensation led 5 dvss d g digital ground 6 leds a o output sending led 7 dvdd a i digital supply 8 enspi d i enable the spi interface 9 swto d i select touch or toggle mode 10 touch_ a / ldb a i/o d i output of the touch function with an analogue switch of typically 30 ? betw een pin 10 and pin 11. in spi operation mode (enspi=high) this pin red e?ndet to the ldb chip select output 11 touch_ b / miso a i/o d z output of the touch function with an analogue switch of typically 30 ? betw een pin 10 and pin 11. in spi operation mode this pin red e - ?ndet to the miso master input slave output output 12 syo dz* synchronisation output (*high resistance for a short timer after power on and spi reset) 13 prox d i proximity function output (active low) 14 syi d i synchronisation input 15 mosi d i spi master output slave input 16 sck d i spi serial clock 1) a = analog, d = digital, g = ground, i = input, o = output, i/o = bidirectional and z = tristate output 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 ???? ??? ???? ???? ???? ???? ???? ????? ??? ???? ??? ???? ??? ???????????? ??????????? ???? / 39
e9 09.01 4 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 tssop 16 package outline sop 16 package outline 1 8 9 n d e1 e e h i nde x a re a a a1 a2 l ph i s eati ng p la ne b c 1 2 3 i nd ex a re a e h d et ai l ' a' e b m ou ld p ar ti ng l in e d et ai l ' b' l d - a - - c - a a1 s ea ti ng p la ne - b - n d et ai l ' a' d et ai l ' b' h x 4 5 o c / 39
5 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 the halios?-switch is based on the principle of a re?ective light barrier. a led transmits light into the surround - ing area. this light is partly re?ected by a translucent surface and an approaching ?nger. the re?ected light is then received by a photodiode. thus the system consists of two optical couplings: one ?xed predetermined by the setup, mainly the surface, and one predetermined by an approaching ?nger. lets take a closer look at the character of a ?nger. a ?nger can be characterised as a re?ector with lambertian characteristics. figure 1.1 shows some samples of diffuse re?ection of human skin (variations due to various re?exion grades). the diffusion of the human skin is characterised by an area ranging from blue to green (about 590 nm) with a low diffuse re?ection and an area from red to infrared with high diffuse re?ection. this characteristic step is generated by the colour of blood and independent of the colour of skin. consequently the use of red or infrared leds for the halios?-switch should be preferred. this spectral range also ?ts ideally the low priced silicone pho - todiodes. the tcnd 3000 module uses a wavelength of 885 nm. the re?ection of clothes in the ir range can not be derived from the visible appearance as shown in figure 1.2. 1 optics 1 .1 optical operation principle figure 1.1 : diffusion of human ?nger / 39
e9 09.01 6 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 the area, where the touch is supposed to take place, is illuminated by the transmitting led and observed by the photodiode. the de?nition of this area is predetermined by the optical setup, especially the overlapping of radia - tion and receiving characteristics of the sending led and photodiode. the sensitivity of the system is speci?ed by a change between the received light resulting from an approaching ?nger in comparison to the received signal, when no object is near the surface. the setup using the tcnd3000 is shown schematically in ?gure 1.3. figure 1.2: diffusion of some clothes / 39
7 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 the light can take three different ways between the transmitting led to the receiving photodiode. the ?rst way is predetermined by the tcnd 3000 module itself (optical coupling d s_int ), the second is ?xed by the set-up (d s_ surf ) and the third way is de?ned by the ?nger (d s_obj ). the internal coupling of the module is designed for stable operation of the ic e909.01. the re?ection resulting from an approaching ?nger, however, should be greater than the one resulting from the internal setup. please note that every surface gives an additional re?ection. the situation can be simulated with ray tracing using a re?ector with lambertian surface characteristics substituting a ?nger. it is also possible to use an analytical description. the radiation characteristic of a led or the receiving characteristic of a photodiode is in good approximation given by: = 0 cos ( ? ) equation 1.1 the exponent is given by the half power angle ? 0.5 : = i n ( 0.5 ) equation 1.2 i n ( cos ( ? 0.5 ) ) the transmitting led and the receiving led have both a half angle of 20, consequently is approximately 11. the ?nger can be characterised as a lambertian re?ector described by the equation 1.1 by setting to 1. to provide a well working system, it is necessary to arrange the optical couplings d s and d c (cf. ?gure 1.3) in a certain ratio and a certain range. the optical coupling is given by the ratio of the received light power compared to the transmitted light power. especially the ratio of the two parts of d s should lie within a certain range. for more details, please refer to the next chapter. tcnd3000 leds ir-emitter leds (transmitter) ir-emitter ledc (compensation) photodiode gnd tin ledc translucent surface d s_obj d s_surf d s = d s_int + d s_surf + d s_obj d s_int d c ? figure 1.3: schematic setup with tcnd 3000 / 39
e9 09.01 8 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 lets take a closer look at the halios? - control constraint. the control constraint requires that the photodiode has to see the same light intensity from both light sources (leds). the elmos ic e909.01 controls the current of the leds. these currents are then translated into light intensity (k led ). the current produced inside the ic is controlled by a dac driven from the loop-value n. the transfer factor is 10 or 20 ma (i max_s ) nominal full range for the transmitting led and 1 or 2 ma (i max_c ) nominal full range for the compensating led. it is also possible to choose between two control principles. one controls both leds against each other (x-control) and the other de - termines the intensity of the transmitting led on a ?xed level (y-control). the system is described by the following equations: for x-control i max _ s n max -n k led d s = i max_c n k led d c equation 1.3 n max n max for y-control i max _ s k led d s = i max_c n k led d c equation 1.4 n max to balance both equations it is necessary to take the ratios of the optical coupling d and the ratio of the cur - rent ranges i max into account. the y-control clips if the ratios are out of balance. the x-control works under any circumstances, but compresses the loop signal to ?t into the range from zero to n max . the ratio of the current ranges can be chosen via parameters in three steps: i max_c = { 0.05, 0.1, 0.2 } equation 1.5 i max_s consequently the ratio of the optical couplings should ?t this range. normally it is not very easy to adjust the leds correctly to meet the speci?cation of d c and d s . using the tcnd 3000 one can save oneself the dif?cult adjusting work, as the development of the module already took this into consideration. the optical couplings are adjusted in such a way, that a ?nger can be detected in a range of 1 to up to 20 mm`s. the absolute value of the optical couplings determines the noise and proximity distance. inside the tcnd 3000 the values of the optical couplings are ?xed reliable levels. using the spi interface it is possible to read the loopvalue n. this value contains all information about the sys - tem. here are some hints to qualify the signal: ? noise (difference between min and max-value) without an object: about 2 to 6 ? loopvalue without an object: 100 to 400 ? change of loopvalue with object (?nger): > 100 always evaluate the combination of surface material and distance to the module. 1.2 optical and geometrical design / 39
9 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 the resulting photodiode current depending on the distance of an object (representing a ?nger) to the tcnd 3000 is shown in ?gure 1.5. please note that the compensating led causes a photodiode current of zero to up to 5 a depending on the loop value. figure 1.4: basic arrangement using tcnd 3000 module supplied by vishay? / 39
e9 09.01 10 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 figure 1.5: photocurrent caused by re?ection vs. distance. (cf. vishay? datasheet ?gure 5) / 39
11 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 it is possible to use a wide variety of materials for the surface, however, some constraints have to be taken into account. these constraints can be divided into two groups according to their mechanical or material properties. mechanical constraints: ? the surface should not move relative to the optic, otherwise the touch-algorithm does not work properly ? the surface should be mechanically stable ? the surface should ?t the requirements of mechanical and chemical stability for your application ? the surface should give the user a mechanical orientation, like a dent or a grove. ? this haptic feedback improves the mobility. material constraints: there are three parameters of the material that should not get mixed up. the visible transparency of a mate - rial is determined by two effects: the absorption in the volume and the diffusion in the volume. the last mate - rial parameter is the diffusion by surface roughness. nearly all arti?cial materials are transparent in the visible and near ir range. the transmitted light power is additionally in?uenced in fully clear materials by the refractive index (re?exion given by the fresnell law). consequently the transmission can reach a maximum of approxi - mately 92% for pmma. there are a lot of pigments and colouring dyes. organic dyes give the visible colour by absorbing some parts of the visible spectral range. they normally do not absorb in the infrared range. inorganic dyes are enclosed particles and give a diffusion of the material. this diffusion exists also in the infrared range. especially the colour white is always created by diffuse wavelength independent re?exion. diffuse surfaces and printing on surfaces gives additional diffusion. the target is to get as much ir light as possible through the surface and to in?uence the focusing of the opto- electronic components as little as possible. table 1.1 gives a rough overview about materials well suited for switch applications. 1.3 surface materials and mechanical set-up type supplier colour remark pmma n 6 n 7 n 8962 degussa roehm? clear pmma white 010 degussa roehm? white transmitter with small half power angle and directly mounted to the surface pmma white 017 degussa roehm? white transmitter with small half power angle and directly mounted to the surface pmma 962 (perspex ? ) ici? black pmma blue 627 degussa roehm? blue pmma 7704 (perspex ? ) ici? blue pmma red 555 degussa roehm? red pmma 4401 (per spex ? ) ici? red pmma green 777 degussa roehm? green plexiglas satinice? clourless degussa roehm? diffuse transmitter with small half power angle and directly mounted to the surface macrolon? ft: 450601 bayer? black table 1.1 : samples of tested materials / 39
e9 09.01 12 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 1.4 design rules to build up a well working switch please take the following steps: 1 . compile your set-up and read out the loop-signal 2 . select the kind of surface material, surface roughness and distance in such a way that the loopsignal ranges between 100 and 400 3 . control the loopsignal noise (good is 2 to 6 peak to peak) 4 . place your ?nger on the switch. the loopsignal should change a minimum of 100 and not go to saturation 5 . repeat step 2. here are some hints concerning the selection and adjustment of the components: ? diffuse material or a rough surface put the material as close as possible to the tcnd 3000 module ? signal change by ?nger too low decrease loop-value without ?nger, reduce surface re?exion; change default state of transmitter and compensator currents ? proximity distance too small use non diffuse surface material; reduce surface re?exion ? noise too high this is caused by a low energy at the photodiode. increase power of transmitter by increasing the current with a current mirror ? proximity-signal without an object this is caused by a top high noise. also a modulated light source with halios? frequency (125 khz) can cause this problem ? a touch is not detected check the amplitude in the loop-signal and the stability of the signal. check the mechanical stability of the surface. ? the system is sensitive to ambient light reduce the noise of the loop-signal; increase the system power by led current; check the dc photodio- de current (less than 1ma); check for modulated ambient light sources; use photodiode with ?lter ? effect of fixs con?guration by setting the fixs con?guration the touch amplitude is in most cases doubled, but the system is more sensitive to the mechanical adjustment ? effects of hics and hicc enabling or disabling both, gives the same sensitivity except that by enabling both the noise increases. enabling hics and disabling hicc gives a sensitive system and disabling hics while enabling hicc leads to a very stable system / 39
13 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 1.5 advanced con?guration in some special cases it might not be possible to achieve a proper functioning via adjusting the led currents using the spi commands or it might not be possible to change the mechanical setup. in such rare cases it could be helpful to adjust the led currents very precisely. therefore use a current mirror circuit as shown in ?gure 1.6. the depicted values are a very good starting point, but should be adjusted to your application. tcnd3000 leds 680 bc857 bc846 vdd ir-emitter leds (transmitter) ir-emitter ledc (compensation) photodiode gnd tin ledc 27 270 vdd gnd gnd to 909.01 pin 6 (leds) 150 1k bc857 bc846 vdd 2.2k adjust 2.2k adjust vdd gnd gnd to 909.01 pin 4 (ledc) to 909.01 pin 2 (tin) 1.8k in case of a very high backscattering from the surface to the module, adjusting the currents will not solve the problem. in such cases the insertion of an additional shielding between the transmitter and the receiver might be a better solution. this can be reached only by ?lling the grove in the module between transmitter and receiv - er by using black epoxy glue (please make sure that the glue is really ir absorbing), or by introducing a mechani - cal shielding from the module up to the surface. these two possibilities are shown in ?gure 1.7. if you use such a set-up please test appropriately and keep the tolerances in mind. figure 1.6: current mirror circuit (shown values are a very good starting point) / 39
e9 09.01 14 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 tcnd3000 possibility 1 filling of ir absorbing epoxy glue leds ir-emitter leds (transmitter) ir-emitter ledc (compensation) photodiode gnd tin ledc tcnd3000 possibility 2 leds ir-emitter leds (transmitter) ir-emitter ledc (compensation) photodiode gnd tin ledc mechanical shield made of black plastic scattering surface figure 1.7: introduction of optical shielding / 39
15 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 2 working principle asic 2.1 block diagram the high ambient light suppression using the halios? principle is based on two light sources which are clocked by inverted phases. the photo-current receiver ampli?es the difference of the received signal in both clock phas - es and modulates the light source intensity in a negative feedback loop in order to compensate the received sig - nal to zero. thus the input ampli?er is always regulated to its most sensitive operation condition independent of the ambient light conditions. the receiving path uses a transimpedance ampli?er with dc-current control to transfer the photo current into a voltage. the signal is then ampli?ed and ?ltered to remove disturbing signals and ampli?er offsets. the demod - ulator samples the voltages at the output of the ampli?er synchronously to the led clocks, takes the difference of the signal in phase a and phase b and delivers the sign of this difference to the digital integrator. the transmitting path produces the signals for the led modulation by converting the integrator output to an analogue voltage. the output drives the compensation led (ledc) as shown in ?gure 2.1 with a voltage control - led current source of maximum 1.5ma output current. the sending led (leds) is driven by a constant current of 10ma. both outputs are then clocked synchronously to the demodulator. the detection algorithm analyses the data sequence of the digital integrator to detect whether an object is sim - ply approaching the sensor or if it is actually touching the surface of the switch. figure 2.8: block diagram e909.01 control filter demod. spi avdd dvdd sck mosi touch a / ldb touch b / miso en_spi swto prox syi syo avss dvss dvdd tin ledc leds / 39
e9 09.01 16 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 2.2 overview basic functions when an object appears in the detection range of the sensor the signal prox is activated. if a touch occurs on the sensor surface a signal is given by closing an analogue switch of 40 ohm between the pins touch_a, and touch_b. with a wipe over the sensor surface the detection algorithm is reset.in order to reduce the current consumption the measurement cycle is activated only for a short time t measure . during the passive time t passive the ic is switched to an operation mode with reduced current consumption. when an object is in the detection area of the sensor the proximity signal is activated and the sampling rate is high. if no object is detected the sensor is switched to stand-by mode with reduced sampling rate in order to minimize the mean current consumption. to change this default con?guration a full bidirectional spi interface consisting of the pins ldb, sck, mosi and miso can be activated with the pin enspi. it is possible to adjust several thresholds and time constants which are used for the proximity, touch and wipe function. additionally it is possible to read back data from the switch to the supervising -controller in this case the output of the digital integrator can be observed directly by the c and it is possible to implement different algorithms for signal detection. if several switches are positioned in close range of each other, the measurement phases can be synchronised in order to minimise disturbances between the switches. the synchronisation bus consists of the pins syi and syo and connects all switches in a loop. 2.2.1 synchronisation the synchronisation is reached by passing a pulse from one switch to the next. the sensor which has activated the measurement cycle switches the output syo to ?high. then the ?rst switch delays the new cycle until the passive time t passive has passed. the ?rst switch is de?ned with a pull-up resistor at pin syo. the synchronisation leads to a reduced noise and improves the ambient light suppression. if the synchronisation pulse is observed by the c it is possible to reduce the noise caused by the communication by delaying the spi commands until the measurement cycles are ?nished. 2.2.2 active - and stand-by - operation mode to reduce the current consumption the measurement phase is only activated for a short time of 25 clock periods (200 s) and the leds are clocked with 125 khz. together with a settling time for the ampli?ers the total meas - urement time has a value of t measure = 464 s. afterwards during the passive time the measurement is stopped and the leds are switched off. when an object (movement) is detected and the proximity signal becomes ?0 the sensor is in the active operation mode for a minimum of 260 ms (minimum active time). in this case the measurement is activated with a rate of 244 hz. when no movement is detected during this time the sensor is switched to stand-by mode and the sampling rate is reduced to 15 hz. if the object is still in the detection area (without a movement) the prox-output stays active (?0), independent of the operation mode (default). by connecting the prox output to the interrupt pin of the supervising c, it is possible to use the proximity event as a wake-up signal for the c. / 39
17 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 2.2.3 detection algorithms the algorithms to detect a switch event are observing the integrator output which is proportional to the modu - lation current of the compensation led. if no object is in the detection area of the sensor and the regulation loop has settled, the integrator signal has a static value. if an object approaches the sensor the integrator output changes its value. as soon as a certain threshold value is reached the proximity signal prox is activated. to detect a touch event the 1st and 2nd derivatives of the integrator output are used additionally. these values are functions of the objects velocity and acceleration. a touch is detected if the object is approaching with a minimum velocity, stops on the sensors surface with a minimum of negative acceleration and remains on the surface of the sensor without moving after the touch for a minimum time of 130 ms (can be adjusted with the parameter totim in table 2.2). this time criterion is used to assure that the indented touch is really detected as such. if the object is removed from the sensor surface the stand-by mode is activated again as soon as the output of the integrator reaches the old value which it had before entering the active mode. if something should fall onto the surface and activate the touch, a time-out function switches back into stand-by mode after global time out (timov C descr. in table 2.2) and the recent static value of the integrator output is used as new reference value for the proximity function. the touch signal output (on pins 10 and 11 or via spi) depends on the pin swto. when this pin is connected to ground, touch is only active as long as the object touches the surface (touch-mode) . when it is connected to supply, it is in toggle-mode : a touch event closes the switch and the touch output stays active as long as the next touch event opens the switch. with a wipe over the sensors surface the detection algorithm is reset. if after a touch some dirt should remain on the sensor, the system will not turn to stand-by mode due to a higher re?ection. in this case a wipe stops the time-out and a new reference will be found. 2.3 spi interface 16 data bits are sent to the e909.01 via spi. the ?rst four bits contain the address bits. these four bits tell the e909.01 its general operation. the next four bits contain the data information. the last eight bits are not used. the spi interface consists of 4 pins: 1. mosi : master out slave in : c => asic 2. sck : serial clock : c => asic 3. ldb : load (active low): c => asic 4. miso : master in slave out : asic => c / 39
e9 09.01 18 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 2.3.1 spi transmission each transmission starts with a falling edge on ldb and ends with a rising edge. during transmission commands and data are shifted according to the following rules 1 . ldb line is active (active ?low) 2 . mosi data are shifted in on the rising sck edge msb ?rst and lsb last 3 . mosi data are read on the falling sck edge. 4 . a command is only carried out on the rising edge of ldb when 16 clock cycles are counted during the last transmission. 5 . miso is active when ldb is ?low and is tristated when ldb is ?high. 6 . sck should remain ?low after the 16th sck falling edge. the following diagram shows one data transmission over the spi-bus. for exact timing please refer to the speci? - cation 03sp0277e. figure 2.9: example of a correct data transmission, command h2200 2.3.2 miso line 16 bits of data are returned to the c on the rising edge of sck. the returned data contains information concer - ning the state of the switch and the value of the dac or the received command. this depends on the parameter retur (default ?low). in the example of ?gure 2.2 the received bits are: 1110001111111110 (with default parameters). this means the e909.01 is in active mode (internal prox, here: high active!), the states movedo and preto are low active and touch, wipe are high active. the integrator value is count=0111111111(511) and the lsb: tmode (high active) indicates that the e909.01 is not in test-mode . retur miso line msb [ 1 ] [ 2 ] [ 3 ] [ 4 ] [ 5 ] [ 6:13 ] [ 14 ] [ 15 ] lsb [ 16 ] low not standby movedo preto touch wipe count[ 9:0 ] tmode high not standby movedo preto touch wipe addr[ 0:3 ] data[ 0:3 ] retur tmode tmode table 2.2 / 39
19 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 bit position name description msb motion this bit is activated when an object is moving inside the sensor area. once the object remains still the signal is deactivated. bit ( 14 ) movedown* this signal is activated when the minimum touch level(thz 2 ) and the minimum velocity level(thd 1 ) have been reached. bit ( 13 ) pretouch* this signal is activated when movedown is active and the deceleration remains under the tha level(this parameter is coupled with thd 1 ). bit ( 12 ) touch if the signal remain in the state pretouch for the required touchtime(totim) the touch signal is activated. bit ( 11 ) wipe this signal is activated when an object slides quickly over the sensor surface. retur = 0 retur = 1 bit ( 10 ) -> count ( 9 ) addr ( 3 ) bit ( 9 ) -> count ( 8 ) addr ( 2 ) bit ( 8 ) -> count ( 7 ) addr ( 1 ) bit ( 7 ) -> count ( 6 ) addr ( 0 ) bit ( 6 ) -> count ( 5 ) data ( 3 ) bit ( 5 ) -> count ( 4 ) data ( 2 ) bit ( 4 ) -> count ( 3 ) data ( 1 ) bit ( 3 ) -> count ( 2 ) data ( 0 ) bit ( 2 ) -> count ( 1 ) na bit ( 1 ) -> count ( 0 ) na lsb testmode this bit indicates that the enspi pin is at half of vdd. it is now possible to conduit the productional tests. note: signals marked with * are active low; all others are active high. data is shifted out on the rising sck edge starting with msb. wipe: this signal resets the detection algorithm to it default state. if in toggle mode(set with pin swto) an active touch signal will not be reset unless the spi cmd. 0 x 1 b** has been sent (rswipe). retur: this bit determines the value that is returned over the spi interface. with the spi cmd 0 x 1 c** the count value is returned, and with the spi cmd. 0 x 1 d** the data returned contains the last spi cmd that was received. / 39
e9 09.01 20 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 2.3.3 address decoding address data hex default signal description 0000 0000 00** - - - unused 0001 01** - - - unused 0010 02** - - - unused 0011 03** - - - unused 0100 04** - - - unused 0101 05** - - - unused 0110 06** enabled g 0 disabled gain setting 6 db. 0111 07** enabled 1000 08** disabled g 1 disabled gain setting 12 db. 1001 09** enabled 1010 0a** enabled hicc disabled high current for compensation led. 1011 0b** enabled 1100 0c** disabled hics disabled high current for sending led. 1101 0d** enabled 1110 0e** disabled fixs disabled fixed current for sending led. 1111 0f** enabled / 39
21 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 address data hex default signal description 0001 0000 1 0** enabled acc_on disabled en/disabled the counters acceleration (see 4.1 ). -enabled -> step size: 1-8 lsd. -disabled -> step size: 1 lsb. 0001 1 1** enabled 0010 1 2** 4 lsb selacc 4 lsb select the maximum integrator step size (see 4.1 ) 0011 1 3** 8 lsb 0100 - 0111 1 4** - 1 7 ** - - - unused 1000 18 ** disabled selde - lay disabled en/disables an additional touch time , which is depending on the signals dynam - ic. it is used for synchronisation (see 4.4 ) 1001 19 ** enabled 1010 1a ** disabled rswipe disabled disables the resetcaused by a detected wipe signal when the switch is in toggle- mode (swto= 1 ) (see 4.2 ) 1011 1b ** enabled 1100 1c ** return counter value retur return counter value retur switches the data which is send out via miso, see section 4.1.3 1101 1d ** return com - mand 1110 1e ** enabled hold- prox disabled if enabled the prox output is held active (low) as long as an object is inside the detection area. 1111 1f ** enabled / 39
e9 09.01 22 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 address data hex default signal description 0010 0000 1 0** 4 lsb thz 1 sets to 3 lsb 1 st threshold for proximity 2 nd threshold for proximity is 2 * thz 1 sensitive not sensitive 0001 2 1** sets to 4 lsb 0010 2 2** sets to 4 lsb 0011 2 3** sets to 5 lsb 0100 - 0111 2 4** - 2 7 ** - - - unused 1000 2 8 ** 32 lsb thz 2 sets to 8 lsb minimum dynamic for touch detection sensitive not sensitive 1001 2 9 ** sets to 16 lsb 1010 2 a ** sets to 32 lsb 1011 2 b ** sets to 64 lsb 1100 2 c ** sets to 128 lsb 1101 2 d ** sets to 192 lsb 1110 2 e ** sets to 256 lsb 1111 2 f ** sets to 512 lsb / 39
23 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 address data hex default signal description 0011 0000 - 0111 30** - 37** - - - unused 1000 3 8 ** 4 lsb/ - 4 lsb (soft) thd 1 / tha 4 lsb/ - 1 lsb 4 lsb/ - 4 lsb velocity and acceleration threshold for touch. very soft soft middle hard 1001 3 9 ** 1010 3a ** 7 lsb/ - 7 lsb 1011 3 b ** 10 lsb/ - 10 lsb 1100 - 1111 3c ** - 3f** - - - unused address data hex default signal description 0100 0000 - 0111 4 0** - 47** - - - unused 1000 4 8 ** 130 ms totim 65 ms touch time (holdtime), constant part of tvalid 1001 4 9 ** 130 ms 1010 4 a ** 130 ms 1011 4 b ** 26 0 ms 1100 4c** 48 s timov touched 32 s prox 8 min duration of time - out when system sate is touched or prox 1101 4d** 48 s 12,5 min 1110 4e** 60 s 16 min 1111 4f** no timeout no timeout / 39
e9 09.01 24 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 address data hex default signal description 0101 0000 50 ** - - - unused 0001 5 1** enabled oscon disabled switches internal oscillator off 0010 - 0100 5 2** - 54** - - - unused 0110 - 1111 56** - 5f** - - - unused address data hex default signal description 0110 0000 - 1111 6* ** - - - unused / 39
25 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 table 2.3: address decoding address data hex default signal description 0111 0000 7 0** 2 dynstep sets to 0 pos./neg. steps greater than dynstep are counted up in the dynamic counters: negcnt and poscnt, otherwise they are in reset. sensitive not sensitive 0001 7 1** sets to 1 0010 7 2** sets to 2 0011 7 3** sets to 3 0100 7 4** 2 prox - num 1 sets to 0 if proxcnt, which counts the number of subsequent samples that pass the 1 st threshold thz 1 , is greater than proxnum 1 , than proximity is detected. sensitive not sensitive 0101 75 ** sets to 1 0110 76 ** sets to 2 0111 77 ** sets to 3 1000 - 1001 78 ** - 79** - - - unused 1010 7a ** 2 prox - num2 sets to 2 if poscnt or negcnt> proxnum 2 proximity is detected sensitive not sensitive 1011 7b ** sets to 3 1100 - 1111 7c ** - 7f** - - - unused address data hex default signal description 1xxx xxxx * * ** - - test mode com - mands dont use ! / 39
e9 09.01 26 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 2.3.4 adjustment of the halios? parameters while using the spi interface the parameterization of the ic via spi by using the parameter commands hicc, hics, fixs (see table 2.3) can lead to a spontaneous activation of the touch-output. this effect is the result of the sudden change of the dac values caused by the adjustment. the touch-output then will remain active for up to 40 seconds until timeout occurs. this behaviour only applies to applications that communicate via spi instead of using the ic stand alone. the necessary procedure to prevent this effect is described below. in this case the enspi pin of the ic has to be connected to an additional digital output from the external control - ler as shown in schematic fig. 2.10. the values of the resistor rd1 and rd2 (values are always equal) are depend - ant on the supply voltage dvdd. it must be ensured that the maximum possible current through enspi is limited to 1ma. avdd tin avss ledc dvss leds dvdd tcnd3000 use ceramic type condensators (1206) for components c1 and c4 enspi e 9 0 9 . 0 1 a c1 10u r4 100k r3 10 rd2 rd1 2,7k 2,7k r1 500 d2 c4 10u c3 47u display led red vdd vdd tin leds gnd sck mosi syi prox syo touch_b touch_a swto miso ldb enspi mosi sck to parameterize the ic, ?rst, enspi must be set low, followed by the two commands a5** and a4**sent via spi. then enspi has to be released (set high) again and the parameter commands can be transmitted. the required timing for this sequence is described in detail in fig. 2.11. all shown delay times, except the duration, are meant as minimum values. figure 2.11: timing diagram of the parameterization sequence figure 2.10: circuit diagram of a freely con?gurable switch ????? ? ? ? ? ??? ???? ???? ??? ???? ???? ???? ????????????? ??????? ???? ???? ? ??? ???? ???? / 39
27 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 the synchronisation is done by passing a pulse from one ic to the next. each ic has an input syi and an output syo. the output syo is connected to the input syi of a neighbouring ic e909.01 in a chain of ic e909.01 or con - nected to its own syi if there is only one switch. the output syo is ?high when an ic e909.01 is performing a measurement cycle. an e909.01 activates when 1. it is a slave e909.01 and there is a falling edge on the input syi 2. it is the master e909.01 and the passive time has elapsed. 2.4 synchronisation prox vdd vdd e909.01 master 100k 100k syi syo prox e909.01 slaves syi syo prox e909.01 syi syo figure 2.12: example of synchronisation of three e909.01 2.4.1 de?nition of master (via resistance 100k) in a chain of e909.01 there is only one master e909.01. the decision which one functions as master depends on the output pin syo. the master e909.01 is de?ned by a pull-up resistor of 100k on its syo output. initially the digital output of this pin is tristated so the value on the pin depends on whether it is connected to a pull-up or not. logic tristate vdd syo_out syo en_syo syo_read 100k after the initial power on or a spi-reset, each e909.01 checks to see if it functions as master or slave. this deci - sion depends on the value of syo_read while en_syo is ?low. the signal en_syo controls the tristate buffer, while it is ?low the pin syo_out is in high resistance state. the value of en_syo is the delayed power-on or spi reset. figure 2.13: decision of master / 39
e9 09.01 28 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 2.4.2 cancelling a touch signal the touch algorithm consists of mainly three states. in the state approx the algorithm has detected an object and the signal proximity is activated. when the object approaches further with a minimum velocity and stops on the sensor surface with a minimum acceleration the pre touch-state is enabled. when the object remains calm on the surface for a certain time the touch-state is entered. to avoid the situation where there occurs a touch by two or more switches at the same time a cancel-pretouch signal is sent over the syo line to all switches. to ensure that the switch with the highest dynamic responds to the touch event, the additional touch time with seldelay (see table 2.2) should be enabled. this means higher dynamic causes less delay. the ?rst switch detecting a touch sends a cancel-pretouch signal on the syo line. each switch in turn cancels its pretouch and sends the cancel-pretouch signal to the next switch. only the switch that originally detected the touch can stop this pulse, so the pulse is going round at least once until it reaches the switch which detected the switch event in the ?rst place. afterwards all other switches are able to detect another touch event. the cancel-pretouch signal is a small pulse which is sent after the measurement cycle is ?nished and a touch has been detected. to decide whether this signal has been sent or not, the time period is measured in which syi is zero after a falling syi event has occurred. if this time is too short then the switch knows that a touch was detected by a neighbouring switch and when it is in state pretouch it will cancel this touch event and change its state to approx. 2.4.3 proximity detection and change of sampling rate if in a chain of several ic`s e909.01 one of the slaves detects an approaching object it cant speed up the sam - pling rate by itself, as only the master chip is able to do this. thus all ic`s e909.01 in a synchronised chain are connected parallel to a pull-up resistor and the master chip can read the common prox signal to change the sampling rate (see ?gure 2.2). to ensure the appropriate functionality the parameter holdprox (see table 2.2) should be set to ?0 to get the internal prox = not standby which indicates the sampling rate. 2.5 analogue parameters the parameters hicc (high current compensation) and hics (high current sender) listed in the address decod - ing table in paragraph 2.3.3 can be used to set the operating point of the halios? loop. additionally a self test can be implemented when using spi interface. by switching the sending current from low to high a touch should be detected. the same effect can be achieved by switching the compensation current from high to low. with fixs (table 2.2) the led driver of the sender can be set to regulated (fixs=0) or ?xed mode (fixs=1). fixs=1 means that the sending led is pulsed with a constant current. by setting fixs=0 the sending current is inversely controlled to the compensation current. this means that if the compensation current increases, the sending cur - rent is decreased by the same relative amount. in this mode the system never saturates and can handle a great variation in optical re?ections. with g0, g1 the gain of the ampli?er is set. it should be set to value that the modulator can differ between sin - gle one lsb changes of the dac. the limiting factor here is the noise of the ampli?er which is about 2.7narms referred to the input. with oscon=0 (see table 2.2) the system can be set to a sleep mode. if this command is sent during a measure - ment phase the system waits until the measurement has ?nished before it stops. / 39
29 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 3 application diagrams 3.1 application diagram of a switch without spi the simplest con?guration consists of one switch ic e909.01 as a single switch without spi interface. the corre - sponding circuit diagram is shown in ?gure 3.1. the touch and the proximity signal are indicated with two leds. with the pin swto one is able to de?ne whether the touch output should be activated only during the time the touch event is detected (touch mode) or if the touch output should toggle its state with each touch event (tog - gle mode). the following voltages must be applied to select the corresponding mode: touch mode: swto = vdd toggle mode: swto = gnd avdd tin avss ledc dvss leds dvdd tcnd3000 enspi e 9 0 9 . 0 1 a c1 10u r4 100k r3 10 r1 500 d2 r2 500 c4 10u c3 47u d1 touch led proximity led vdd vdd leds tin gnd beeper sck mosi syi prox syo touch_b touch_a swto figure 3.12: circuit diagram of a single switch without spi interface 3.2 how to increase the detection range the sensitivity or the detection range is proportional to the sending current (pin leds) and inverse proportional to the compensation current (pin ledc). the ic e909.01 allows to increase the sensitivity by internally in?uenc - ing the range of the led currents with spi commands. with the spi command 0d it is possible to increase the sending current range from 10ma to 20ma. by using the spi command 0a the compensation current range is reduced from 2ma to 1ma. the two commands allow to improve the sensitivity of the sensor by a factor of four. with the external drivers shown in figure 3.2 it is possible to increase the currents to larger values than it is pos - sible with the internal drivers. with the emitter resistor of pnp2 the compensation current can be adjusted and it is possible to adapt the led current for both channels independently of each other. if the sensitivity is enlarged one must pay attention to avoid saturation of the measurement signal. should this happen, the stray-light from the sending led to the photodiode must be reduced by using an optical blocking layer between the translucent surface and the tcnd3000. this includes also the air-gap between both lenses of the tcnd3000. please refer to chapter 1.5. / 39
e9 09.01 30 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 another possibility to avoid saturation of the measurement signal is to regulate both the sending current and the compensation current. in normal mode after power up only the compensation current is regulated (fixs is enabled). by using the spi command 0e (fixs is disabled) the sending led current is regulated according to the equation i send = i r ange_send * (1 C loopvalue / 1023) while the compensation current is regulated according the following equation i comp = i r ange_comp * loopvalue / 1023. in this case, however, the sensitivity is decreased when the measurement signal approaches the limit of the range in order to avoid saturation. thus the most effective way to avoid saturation in a system with high sensi - tivity is to reduce the stray light as described above. avdd tin avss ledc dvss leds dvdd tcnd3000 enspi e 9 0 9 . 0 1 a c1 10u r4 100k r3 10 r14 2,2k rd2 0 r1 500 d2 c4 100n c3 47u proximity led vdd vdd tin leds bc857 pnp2 bc817 npn2 gnd c3 47u sck mosi spi signals syi prox syo touch_b touch_a swto miso ldb mosi sck r15 1k r16 2,2k r17 1,8k r10 27 bc857 pnp1 bc817 npn1 r12 680 r11 270 r13 150 figure 3.13: control of the optomodule tcnd 3000 with external led drivers / 39
31 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 3.3 cascading of optical switches several switches can build a group by using the synchronisation bus. this has several advantages. first, one proximity function for all switches in the group can be realized. this makes it possible to illuminate se - lected parts of the control panel and de?ne groups of functions. the second advantage is the possibility to avoid unwanted operation by cancelling parasitic touch events. if one switch detects a touch event all other switches are disabled for a short time. a third advantage is that the measurement phase of switches among one group is activated sequentially. this allows switches to be located close together avoiding disturbances if light from one switch is re?ected to another switch. the schematic below shows a group of two switches which are connected with the synchronisation bus. avdd tin avss ledc dvss leds dvdd tcnd3000 enspi e 9 0 9 . 0 1 a c1 10u r4 100k r3 10 r6 10 r1 500 d2 r2 500 c4 10u c3 47u d1 touch led a shared proximity led for both switches master (with pull up resistor at pin syo) vdd vdd leds tin gnd sck mosi syi prox syo touch_b touch_a swto avdd tin avss ledc dvss leds dvdd tcnd3000 enspi e 9 0 9 . 0 1 a c5 10u r5 500 c2 10u d3 touch led b slave (with pull up resistor at pin syo) vdd leds tin sck mosi syi prox syo touch_b touch_a swto the synchronisation bus is activated by connecting the syo pin of one switch to the syi pin of the next switch. the last switch is then connected to the ?rst switch building a closed loop. one switch in this loop is de?ned as the master by using a pull-up resistor at its syo pin and connecting all prox output pins with one pull-up resis - tor. if one switch in the group detects an approaching object all other switches are switched from standby mode to active mode. the master synchronizes the sampling rate, the pretouch time (parameter totim in table 2.2) and the global timeout (parameter timov in table 2.2) of all switches in the group. figure 3.4 shows how parasitic touches are cancelled. if several switches are in the pretouch phase at the same time the switch that leaves the pretouch time ?rst cancels all other pretouch phases that are active at this time. this is done by sending a pulse on the synchronisation bus from one switch to the next. if several switches have activated their pretouch phase during the same measurement cycle they will leave their pretouch phase at the same time. in this case the order in the chain of the synchronisation bus determines which switch will have a valid touch. this means the ?rst switch seen from the front of the chain will accept the touch. figure 3.14: circuit diagram of two synchronised switches / 39
e9 09.01 32 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 it is also possible to prioritise the switch with the largest signal amplitude to accept the touch. with the parame - ter seldelay (parameter seldelay is described in table 2.2) this option can be enabled. in this case the constant pretouch time is extended by a variable part, which is proportional to the signal amplitude. if now several switches are entering the pretouch phase during the same measurement cycle the switch with the largest sig - nal amplitude will win and activate its touch output. 3.4 reference design the circuit diagram (?gure 3.5) below shows an application where the spi interface is not used in normal opera - tion. it is, however, possible to activate the spi interface for test purpose by removing the components rd1, rd3, rd4, rd5, rd6 and inserting component rd2. in the case of an activated spi interface the touch output is not ac - tive any more. due to the synchronous demodulation principle of the halios? regulation loop asynchronous disturbances outside the modulation frequency band are not critical and do not disturb the measurement. only synchronous electrical and optical disturbances can in?uence the measurement. thus it is important to avoid electrical cou - pling of the modulation frequency to the photodiode input and the analogue supply of the e909.01 ic. this can be avoided by shielding the photodiode connection line with analogue ground, which should be designed like a grounded coplanar line. additionally the analogue supply should be decoupled with a lowpass of ?rst order given in the example by the components r3 and c4. the ground connection between tcnd3000 and e909.01 should be of low resistance type with a ground plane. pr etou ch ti me s wi tc h 1 p ar ameter : t ot im to uc h ac c epted sw it ch 2 : sw it ch 1 : sw it ch 3 : pr etou ch ti me s wi tc h 2 pr etou ch ti me s wi tc h 3 sw it ch 4 : pr etou ch ti me s wi tc h 4 to uc h ca nc el le d to uc h ac c epted ti me figure 3.15: prioritisation of touch events by disabling other touches during the pretouch time / 39
33 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 avdd tin avss ledc dvss leds dvdd tcnd3000 enspi e 9 0 9 . 0 1 a c1 10u r4 100k rd6 0 rd5 0 rd4 0 rd3 0 r3 10 rd2 0 rd1 0 r1 500 d2 r2 500 c4 10u c3 47u d1 touch led proximity led sck mosi miso ldb vdd vdd leds tin gnd beeper sck mosi syi prox syo touch_b touch_a swto do not insert component rd2 in case spi is not used! for test purpose the spi interface can be activated by removing the components rd1, rd3, rd4, rd5, rd6 and inserting component rd2. use ceramic type condensators for components c1 and c4 figure 3.16: schematic diagram of test circuit with spi interface figure 3.17: pcb layout of test circuit (top side) / 39
e9 09.01 34 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 figure 3.18: pcb layout of test circuit (bottom side) 4 related documents dokument-no.: 03sp0277e.xx speci?cation e909.01 [1] / 39
35 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 5 record of revisions chapter rev. change and reason for change date released 3.3 1 figure 3.14 03.04.2006 rme/zoe - 1 page 39 removed - page 5 moved to page 38 03.04.2006 rme/zoe / 39
e9 09.01 36 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 contents system comparison.................................................................................................................................................................................... 2 sop16 package outline and description.............................................................................................................................................. 4 tssop16 package outline and description......................................................................................................................................... 4 1 optics ........................................................................................................................................................................................................... 5 1.1 optical operation principle .......................................................................................................................................................... 5 1.2 optical and geometrical design ............................................................................................................................................... 8 1.3 surface materials and mechanical set-up ............................................................................................................................. 1 1 1.4 design rules ................................................................................................................................................................................... 1 2 1.5 advanced con?guration ............................................................................................................................................................. 1 3 2 working principle asic ......................................................................................................................................................................... 1 5 2.1 block diagram ................................................................................................................................................................................ 1 5 2.2 overview basic funktions ......................................................................................................................................................... 1 6 2.2.1 syncronisation ..................................................................................................................................................................... 1 6 2.2. 2 a ctive and stand-by operation mode........................................................................................................................ 1 6 2.2.3 detection algorithms........................................................................................................................................................ 1 7 2.3 spi interface.................................................................................................................................................................................... 1 7 2.3.1 spi transmission................................................................................................................................................................... 1 8 2.3.2 miso line............................................................................................................................................................................... 1 8 2.3.3 address decoding............................................................................................................................................................... 2 0 2 .3.4 a djustment of the halios? parameters while using the spi interface........................................................... 2 6 2. 4 synchronisation............................................................................................................................................................................ 2 7 2.4.1 de?nition of master (via resistance 100k).................................................................................................................. 2 7 2. 4.2 cancelling a touch signal................................................................................................................................................ 2 8 2. 4.3 proximity detection and change of sampling rate................................................................................................. 2 8 2. 5 analogue parameters................................................................................................................................................................. 2 8 3 application diagrams............................................................................................................................................................................ 29 3.1 application diagrams of a switch without spi.................................................................................................................... 29 3.2 how to increase the detection range.................................................................................................................................... 29 3.3 cascading of optical switches................................................................................................................................................... 3 1 3.4 reference design.......................................................................................................................................................................... 32 4 related documents............................................................................................................................................................................... 3 4 5 record of revision.................................................................................................................................................................................. 3 5 contents....................................................................................................................................................................................................... 36 list of figures ...................................................................................................................................................................................... 3 7 list of tables ........................................................................................................................................................................................3 7 / 39
37 e9 09.01 elmos semiconductor a g application note qm- no.: 03an0801e .0 1 list of figures figure 1.1 : diffusion of human ?nger..................................................................................................................................................... 5 figure 1.2 : diffusion of some clothes.................................................................................................................................................... 6 figure 1.3 : schematic setup with tcnd 3000..................................................................................................................................... 7 figure 1.4 : basic arrangement using tcnd 3000 module supplied by vishay?.................................................................... 9 figure 1.5 : photocurrent caused by re?ection vs. distance. (cf. vishay? datasheet ?gure 5)........................................... 1 0 figure 1.6 : current mirror circuit (shown values are a very good starting point).................................................................. 1 3 figure 1.7 : introduction of optical shielding...................................................................................................................................... 1 4 figure 2.8 : block diagram e909.01........................................................................................................................................................ 1 5 figure 2.9 : example of a correct data transmission, command h2200.................................................................................... 1 8 figure 2.10 : circuit diagram of a freely con?gurable switch....................................................................................................... 2 6 figure 2.11 : timing diagram of the parameterization sequence................................................................................................ 2 6 figure 2.1 2 : example of synchronisation of three e909.01 ic`s................................................................................................... 2 7 figure 2.1 3 : decision of master.............................................................................................................................................................. 2 7 figure 3.12 : circuit diagram of a single switch without spi interface....................................................................................... 29 figure 3.13 : control of the optomodule tcnd 3000 with external led drivers.................................................................... 3 0 figure 3.14 : circuit diagram of two synchronised switches.......................................................................................................... 3 1 figure 3.15 : prioritisation of touch events by disabling other touches during the pretouch time............................... 3 2 figure 3.16 : schematic diagram of test circuit with spi interface.............................................................................................. 3 3 figure 3.17 : pcb layout of test circuit (top side)............................................................................................................................... 3 3 figure 3.18 : pcb layout of test circuit (bottom side)..................................................................................................................... 3 4 list of tables table 1.1 : samples of tested materials.................................................................................................................................................. 1 1 table 2.2 ......................................................................................................................................................................................................... 1 8 table 2.3 : address decoding................................................................................................................................................................... 2 5 / 39
e9 09.01 38 elmos semiconductor a g application note qm-no.: 03an0801e.0 1 warning C life support applications policy elmos semiconductor ag is continually working to improve the quality and reliability of its products. never - theless, semiconductor devices in general can malfunction or fail due to their inherent electrical sensitivity and vulnerability to physical stress. it is the responsibility of the buyer, when utilizing elmos semiconductor ag products, to observe standards of safety, and to avoid situations in which malfunction or failure of an elmos semiconductor ag product could cause loss of human life, body injury or damage to property. in development your designs, please ensure that elmos semiconductor ag products are used within speci?ed operating ranges as set forth in the most recent product speci?cations. general disclaimer information furnished by elmos semiconductor ag is believed to be accurate and reliable. however, no respon - sibility is assumed by elmos semiconductor ag for its use, nor for any infringements of patents or other rights of third parties, which may result from its use. no license is granted by implication or otherwise under any patent or patent rights of elmos semiconductor ag. elmos semiconductor ag reserves the right to make changes to this document or the products contained therein without prior notice, to improve performance, reliability, or manufacturability . application disclaimer circuit diagrams may contain components not manufactured by elmos semiconductor ag, which are included as means of illustrating typical applications. consequently, complete information suf?cient for construction purposes is not necessarily given. the information in the application examples has been carefully checked and is believed to be entirely reliable. however, no responsibility is assumed for inaccuracies. furthermore, such infor - mation does not convey to the purchaser of the semiconductor devices described any license under the patent rights of elmos semiconductor ag or others. copyright ? 2 00 6 elmos semiconductor a g reproduction, in part or whole, without the prior written consent of elmos semiconductor a g , is prohibited . / 39
elmos semiconductor ag C headquarters heinrich-hertz-str. 1 | 44227 dortmund | germany phone + 49 (0) 231 - 75 49 - 0 | f ax + 49 (0) 231 - 75 49 - 149 sales@elmos.de | www.elmos.de elmos semiconductor ag C munich branch am ge?gelhof 12 | 85716 unterschlei?heim | germany phone + 49 (0) 89 - 318 370 - 30 | f ax + 49 (0) 89 - 318 370 - 31 sales@elmos.de | www.elmos.de elmos semiconductor ag C stuttgart branch max-eyth-str. 35 | 71088 holzgerlingen | germany phone + 49 (0) 70 31 - 63 19 91 | f ax + 49 (0) 70 31 - 63 19 97 sales@elmos.de | www.elmos.de mechaless systems gmbh | a member of the elmos group technologiepark karlsruhe | albert nestler str. 10 | 76131 karlsruhe | germany phone +49 - 721 - 62698 - 00 | fax +49 - 721 - 62698 - 11 info@mechaless.com | www.mechaless.com elmos north america, i nc. 31700 west 13 mile road suite 110 | farmington hills | mi 48334 | usa phone + 1 - 248 865 32 00 | f ax + 1 - 248 865 3203 sales-int@elmos.de | www.elmos.de elmos north america, inc. kokomo design center 2747 south albright r oad | kokomo | in 46902 | usa phone + 1 - 765 453 77 3 0 | f ax + 1 - 765 453 77 31 sales-int@elmos.de | www.elmos.de elmos france s.a. 29, rue de peupliers | 92752 nanterre cedex | france phone + 33 (0) 1 - 46 52 59 59 | f ax + 33 (0) 1 - 42 42 95 54 sales-int@elmos.de | www.elmos.de elmos representative in japan C musashino corporation tohchiku bldg. | 2-14-18 | minato-ku | tokyo 108-0023 | japan phone + 81 - 3 - 34 53 - 33 51 | fax + 81 - 3 - 3 4 53 - 33 5 0 info@musashinocorp.com elmos distr ibution line C channel microelectronic gmbh alleenstr. 29 /3 | 73730 esslingen | germany phone + 49 - 711 - 930 721 - 30 | fax + 49 - 711 - 930 721 - 40 info@channel-microelectronic.de 39 / 39

▲Up To Search▲

Price & Availability of E90901

	To Download E90901 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .