? by semikron b 14 C 101 0898 absolute maximum ratings (t a = 25 c) symbol term values units v dd15v v dd5v v ih v il v su f sw t op / t stg 15 v supply voltage (reference for output signals) 5 v supply voltage (reference for input signals) input signal voltage (high) max. input signal voltage (low) min. supply undervoltage monitoring us- ing v dd15v switching frequency operating/storage temp. 18 6 v dd5v + 0,3 gnd - 0,3 13,5 50 C 25 ... + 85 v v v v v khz c electrical characteristics (t a = 25 c) 1) symbol term values units v dd15v v dd5v v band- gap i s5v i s15v t d 15 v supply voltage 5 v supply voltage reference voltage 10 v supply current (v dd5v ); typ 4) supply current (v dd15v ); typ 4) propagation time 15 + 5 % 5 + 5 % 9,99 ... 10,01 3 15 860 v v v ma ma ns t tdswitch 2) dead time of interlock; typ. 0, 1, 2, 3, 4 m s t supswitch t supreset short pulse suppression top- bot ;typ pulses are suppressed pulses are not suppressed short pulse supppression re- set;typ. < 480 3) > 640 9 ns ns m s input signal top, bottom, select, tdt1, tdt2 v it+ v it- r down r up input threshold voltage (high) input threshold voltage (low) internal pull down resistor (top; bottom) internal pull up resistor (select, tdt1, tdt2) 3,7 + 0,2 1,9 + 0,2 66 + 2 64 + 2 v v k w k w error input signals toperr, boterr v et+ v et- r eup t swosz t td input threshold voltage (high) input threshold voltage (low) internal pull up resistor oszillator frequency dc/dc-conver- ter time of interlock dc/dc-converter > 3,55 < 1,3 27 + 0,2 500 3) 250 v v k w khz ns error input signal senseerr v et+ v et- r eup input threshold voltage (high) input threshold voltage (low) internal pull up resistor 3,4 + 0,2 2,2 + 0,2 36 + 2 v v k w output signal error; tpw, tw i outmax max. output current at v dd5v + 5ma v outmax max. output voltage at + 5 ma 4,8 v v outmin min. output voltage at - 5 ma 0,22 v output signal topout; botout; tr1p; tr1n; tr2p; tr2n r ti t r typ. t f typ. inhibit time for v ce; err rise time fall time 2 25 5) 35 5) m s ns ns semidriver ? igbt driver circuit skic 2001 preliminary data features igbt-halfbridge driver circuit with protection functions ? interlock of top and bottom switches of one halfbridge ? short pulse suppression ? temperature monitoring ? supply undervoltage protection ? v ce error protection ? over-current error input ? generation of the system clock ? integrated dc/dc-converter driver circuit ? error monitoring typical applications ? driving of igbts - for halfbridge configuration, also for sixpack and single switch possible - due to isolation (magnetic transformer, optocoupler) can be used for voltages > 1200 v and high power applications evaluation boards available on request 1) values for v dd15v ; v dd5v ; f sw = 25khz 2) input select = low = t td = 0 m s 3) with f sw = 8 mhz at osc1, osc2 4) stand by 5) capacitive load (max) < 1 nf at v dd15v = 15 v package sop 28
? by semikron b 14 C 102 0898 pin array: pin-no. terminal function 1 tdt2 code for interlock time 2 sensb input analogue sense b 3 sensa input analogue sense a (type kty85, optional) 4rset input, analogue temp. sense resistance for adjustment of comparator threshold 5 error output error signal 6 sensb_out output for overtemperature signal 7 fout system clock output 8 osc1 input oscillator 9 osc2 input oscillator, external switching 10 cpor time constante for power on reset 11 tr1p output dc/dc-converter 12 tr2p output dc/dc-converter 13 tr2n output dc/dc-converter 14 tr1n output dc/dc-converter 15 vdd15v supply voltage 15 v 16 botout driver output bottom 17 gnd gnd 18 topout driver output top 19 vdd15v supply voltage 15 v 20 vdd5v supply voltage 5 v 21 senseerr input error signal, secondary side 22 boterr input error signal, secondary side 23 toperr input error signal, secondary side 24 error output error signal 25 top driver input top 26 bottom driver input bottom 27 select interlock on/off 28 tdt1 code or interlock time fig. 1 functional block diagram of the control ic (SKIC2001) inside a propulsion control
? by semikron b 14 C 103 0898 overview the integrated intelligent controller circuit (SKIC2001) presented for the control of igbts, especially in a halfbridge, for high power applications (up to 1,700v and several hundred amperes) and frequencies up to 50khz. it includes several driver, protection and monitor functions. fig. 1. shows the functional block diagram of the control ic inside a propulsion control. it consists of a digital control unit, mostly a microprocessor (p), the control ic (skic 2001), a potential separation (ferrite signal transformer or opto-couplers), the gate driver stages, an igbt halfbridge and a consumer, in this case a motor. with the help of the digital unit a pulse frequency modulation of the igbt driver signals is possible and, therefore, a power control of the consumer can be realized. the developed control circuit contains the signal processing, power supply, the driving and monitoring functions for two igbts in a halfbridge (application also for sixpack and single switch possible). a power supply of 5v and 15v is necessary. the most important parts, functions, connections and in- and outputs are shown in fig. 1: ? the forward branch with selector, switch on delay, short pulse suppression, driver and signal transformer to the secondary side (high voltage side) ? the backward branch with error detection and process- ing (undervoltage, temperature, v ce and overcurrent) ? the additional part with clock generator, power supply control and dc/dc converter circuit the control circuit has several inputs, some of them with a schmitt-trigger characteristic for increased noise immunity. top and bottom are the main control inputs. reset sets back the error storage. with tdt1, tdt2 and select a switch on delay between 0 and 4s can be chosen. sensa - sensb (temperature sensor) and rset are optional inputs, if the customer applies a temperature monitoring. as temperature sensor a kty85 is used which is insulated placed on the dcb- substrate. so the temperature of the heat sink is determined. with input rset the variation of the comparator thresholds (a and b) or adaptations to an other sensor are possible with the help of an external resistance. the error signal of comparator a sets the internal error storage. the error signal of comparator b lies at output sensb_out. with the use of ferrite signal transformers the information between primary and secondary side may flow in both directions and high levels of dv/dt and insulation are guaranteed (opto-couplers are also possible). the high frequency dc/dc converter avoids the requirement of an externally insulated power supply to obtain the necessary voltage and power for the igbt gates. for this operation the dc/dc converter circuit supplies a 15v signal with a frequency of 500khz. there is the possibility to use one halfbridge of external power mosfet (1 pmos and 1 nmos) for a lower power supply or a bridge (2 pmos and 2 nmos) for a higher power supply. the igbt driver stages are externally placed. so the stages can be matched to the respective power range and the optimum function (switching frequency and gate charge of the igbts, negative switch off voltage, soft turn off). a short circuit at the igbt driver stages can be monitored by a permanent control of the collector- emitter-voltage (optionally). in general this method is used, but it has the disadvantage, that a time of a few s has to be waited, until we can decide between a normal switch on or a short circuit by the v ce -value. a better and faster method is the evaluation of a differential quotient of the v ce -drop. in the case of a detected short circuit, the igbt is switched off immediately and an error signal v ce -error is transformed to the control ic. another (optional) way to detect a short circuit is the use of a current sensor at the output of the halfbridge (fig. 1). for high power application a current measuring signal is fundamentally indispensable for an optimum microprocessor control of the propulsion system. we use a newly developed compensating current sensor on the basis of a magnetic field sensor. it can be placed outside or inside the power module. the sensor current (in a ratio of 2000 : 1 to the output current) is converted into a proportional analog voltage signal in the separate sensor circuit and evaluated by the microprocessor. in addition the sensor circuit contains a comparator stage where the same signal is also used for the overcurrent monitoring of the igbts. in case of an overcurrent the igbts are switched off directly in about 1s and then an error signal i err is sent to the control ic. the advantage of this solution is the saving of the expensive v ce - monitoring and the very short reaction time to a short circuit. an internal protection function of the skic 2001 is the power supply control. the circuit will be blocked, if the 15v-power supply drops under a value of about 13,5v. in this case a safe function, especially of the transformers, cant be guaranteed any longer. all detected error signals are processed in the control ic. the forward driver signal is blocked or the igbts are switched off and error signals are given at the output to the microprocessor (error and error for undervoltage of power supply, v ce -error and over temperature). the error storage can be reset by a reset pulse, which is generated, if 9 m s the inputs (top, bottom) are low.
|
