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SM8134A White LED Driver IC
OVERVIEW
The SM8134A is a charge pump type white LED driver. It can drive 1 to 4 backlight white LED connected in parallel and 1 flash white LED, making the device ideal for camera-equipped cellular phones. The charge pump switches between x1 to x1.5 boost mode in response to LED drive current requirements to extend battery life to the maximum. The boost switching occurs in response to the drive current of all the connected LED and thus supports variations in LED forward-bias voltage drop (VF). Each LED drive current is controlled by a 5-channel LED drive current control circuit. The backlight LED drive current and ON/OFF control, and flash LED drive current and ON/OFF control are all set by 3-wire serial interface data input. Also, an under voltage lockout (UVLO) circuit is built-in to prevent incorrect operation when the battery voltage drops.
FEATURES
I I
PINOUT
(Top view)
GND DIN2 EN SCK DIN3 DIN4 DIN5 PGND C1P C1M C2M C2P SDA DIN1 VOUT VIN
I
I
I
I
I I I I
I
I I I I I I
I
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Noise reduction due to charge pump boost circuit Automatic charge pump switching to conserve power Drives 1 to 4 backlight white LED (30mA/ch at maximum setting) Drives a flash white LED (150mA at maximum setting) Backlight and flash white LED brightness adjustment 3-wire serial input interface for all setting and control Under voltage lockout (UVLO) circuit built-in Soft start circuit built-in Thermal protection circuit built-in Input voltage range * No-load current (IOUT = 0mA): 2.7 to 4.6V * Load current (IOUT = 80mA): 3.0 to 4.6V * Load current (IOUT = 180mA): 3.3 to 4.6V * Load current (IOUT = 200mA): 3.4 to 4.6V Quiescent current * Not-switching (x1.0 mode): 0.3mA (typ) * Switching (x1.5 mode): 1.7mA (typ) Standby current: 0.01A (typ) Operating frequency: 750kHz (typ) Maximum backlight LED current: 30mA/ch Maximum flash LED current: 150mA All LED total maximum current: 200mA Backlight LED current matching (ILED = 20mA) : 3% Flash LED current accuracy (ILED = 150mA) : 6.7% Packages: 16-pin QFN
PACKAGE DIMENSION
(Unit: mm)
TOP VIEW 3.0 0.08 B A 3.0 0.08 0.3 0.1 3 = 1.5 0.05 BOTTOM VIEW 1.8
0.5
1.8 C 0.3 0.22 0.05
0.2 S A B 0.1 0.05 S 0.2 S
0.05 M S A B
0.2 0.05
0.05 S 0.5
APPLICATIONS
I I I I
Cellular phone Digital still camera PDA Portable games
ORDERING INFORMATION
Device SM8134AB Package 16-pin QFN
0.7 0.05
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SM8134A
BLOCK DIAGRAM
VIN C1M C1P C2M C2P
Charge pump 1/ 1.5
VOUT
Thermal shut down Output voltage control UVLO Current control & Current detect Control logic DIN5 DIN1 DIN2 DIN3 DIN4
SCK SDA EN
GND
PGND
PIN DESCRIPTION
Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Name C1P C1M C2M C2P VIN VOUT DIN1 SDA SCK EN DIN2 GND DIN3 DIN4 DIN5 PGND I/O - - - - - O O I I I O - O O O - Description Charge pump capacitor connection 1P Charge pump capacitor connection 1M Charge pump capacitor connection 2M Charge pump capacitor connection 2P Voltage supply LED drive voltage output LED drive current control output 1 (connect to ground when not used) Serial data input Serial data clock input Serial interface enable input LED drive current control output 2 (connect to ground when not used) Ground LED drive current control output 3 (connect to ground when not used) LED drive current control output 4 (connect to ground when not used) LED drive current control output 5 (connect to ground when not used) Charge pump ground connection
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SM8134A
SPECIFICATIONS
Absolute Maximum Ratings
GND = PGND = 0V Note. The device may suffer breakdown if any one of these parameter ratings is exceeded.
Parameter Supply voltage range Input voltage range Output voltage range VOUT output current Power dissipation Junction temperature Storage temperature range *1. When mounted on a 4-layer PCB. Symbol VIN VEN, VSCK, VSDA VDIN1 to 5 VOUT IOUT PD TJMAX Tstg Rating -0.3 to 5.5 -0.3 to VIN + 0.3 -0.3 to VIN + 0.3 5.5 500 800 (Ta = 25C)*1 +125 -55 to +125 Unit V V V V mA mW C C
800 800 Power dissipation [mW] 640 600 480 400 320
200
0 25 35 45 55 65 75 85 Operating temperature [C]
Recommended Operating Conditions
GND = PGND = 0V
Rating Parameter Pin Symbol VIN1 VIN2 Supply voltage range VIN VIN3 VIN4 Input voltage range Ambient temperature range EN, SCK, SDA - VES Ta Conditions min x1.0 mode, IOUT = 0mA x1.5 mode, IOUT = 80mA, VF = 3.5V*1 x1.5 mode, IOUT = 180mA, VF = 3.5V*1 x1.5 mode, IOUT = 200mA, VF = 3.5V*1 Each logic-level pin 2.7 3.0 3.3 3.4 0 -30 typ 3.6 3.6 3.6 3.6 - - max 4.6 4.6 4.6 4.6 VIN +85 V V V V V C Unit
*1. The maximum value of VF in the drive LED
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SM8134A
Electrical Characteristics
DC Characteristics GND = 0V, VIN = 3.6V, Ta = 25C unless otherwise noted.
Rating Parameter Standby current Quiescent current Maximum output voltage Maximum output current Operating frequency Internal circuit power-ON reset time*1 Soft start time LED drive pin leakage current LED drive current matching LED drive current 1 LED drive pin voltage 1*2 LED drive current 2 LED drive pin voltage 2*2 Under voltage lockout threshold*3 Thermal protection circuit operating temperature*1 Thermal protection circuit hysteresis*1 Logic-level input voltage Pin VIN VIN VOUT VOUT C1M VIN DIN1 to 5 DIN1 to 5 DIN1 to 4 DIN1 to 4 DIN1 to 4 DIN5 DIN5 - - - EN, SCK, SDA EN, SCK, SDA Symbol ISTB IDD1 IDD2 VOUT IOUT fOSC TPOR TSS ILEAK1 to 5 ILED ILED1 to 4 VDIN1 to 4 ILED5 VDIN5 VUV TSD TSDHYS VIH VIL IIL IIH HIGH-level input voltage range LOW-level input voltage range EN = SCK = SDA = VIN EN = SCK = SDA = GND Standby mode x1.0 mode, no load x1.5 mode, no load x1.5 mode VOUT maximum voltage x1.5 mode x1.5 mode switching frequency Time from when power is applied until internal circuit reset Time between EN signal falling edge and LED turning ON Standby mode, VDIN1 to 5 = VIN x1.0 mode, matching between channels with ILED1 to 4 = 20mA setting x1.0 mode, ILED1 to 4 = 20mA setting ILED1 to 4 = 20mA setting x1.5 mode, ILED5 maximum setting IDIN5 maximum setting VIN falling Condition min - - - 4.6 200 650 - - - -3.0 19.0 - 140 - 1.6 - - 1.8 - - -1.0 typ 0.01 0.3 1.7 4.9 - 750 0.05 1.0 0.01 - 20.0 160 150 400 1.9 170 20 - - - - max 1.00 1.0 4.0 5.2 - 850 1.0 3.0 1.00 +3.0 21.0 - 160 - 2.2 - - - 0.6 1.0 - A mA mA V mA kHz ms ms A % mA mV mA mV V C C V V A A Unit
Logic-level input current
*1. Design guaranteed value *2. Pin voltage value which switching x1.0 mode to x1.5 mode when LED current shortage detection *3. When UVLO is active, the output is stopped and internal register is reset.
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SM8134A AC Characteristics GND = 0V, VIN = 3.6V, Ta = 25C unless otherwise noted.
Rating Parameter SCK clock cycle SCK HIGH-level pulse width SCK LOW-level pulse width EN setup time EN hold time EN recovery time Write data setup time Write data hold time Symbol tSCK tWH tWL tCS tCH tCR tDS tDH Condition min 2000 800 800 1000 800 1000 600 600 typ - - - - - - - - max DC - - - - - - - ns ns ns ns ns ns ns ns Unit
EN tCS SCK tWH tSCK
tDH
tWL
tCR
tCH
tDS
SDA
Data input timing diagram
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SM8134A
VOUT EFFICIENCY
100
VOUT power efficiency [%]
90
VF = 3.2V
80
VF = 3.4V VF = 3.6V VF=3.8V
70
60
50 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6
VIN [V]
Efficiency of PIN vs. POUT Backlight LED x 4pcs, ILED1 to 4 = 20mA, Flash LED x 1pc, ILED5 = 0mA, IOUT = 80mA
100
VOUT power efficiency [%]
90
VF = 3.2V
80
VF = 3.4V VF = 3.6V VF=3.8V
70
60
50 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6
VIN [V]
Efficiency of PIN vs. POUT Backlight LED x 3pcs, ILED1 to 4 = 16mA, Flash LED x 1pc, ILED5 = 0mA, IOUT = 48mA
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SM8134A
100
VOUT power efficiency [%]
90
80
VF = 3.2V VF = 3.4V VF = 3.6V VF=3.8V
70
60
50 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6
VIN [V]
Efficiency of PIN vs. POUT Backlight LED x 4pcs, ILED1 to 4 = 20mA, Flash LED x 1pc, ILED5 = 120mA, IOUT = 200mA
100
VOUT power efficiency [%]
90
80
VF = 3.2V VF = 3.4V VF = 3.6V VF=3.8V
70
60
50 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6
VIN [V]
Efficiency of PIN vs. POUT Backlight LED x 3pcs, ILED1 to 4 = 16mA, Flash LED x 1pc, ILED5 = 150mA, IOUT = 198mA
SEIKO NPC CORPORATION --7
SM8134A
FUNCTIONAL DESCRIPTION
Serial Interface
The SM8134A uses a 3-wire serial interface to control each setting. Input data on SDA is input MSB first in an 8 clock pulse cycle structure, with the first 4 cycles of data setting the mode and the next 4 the corresponding mode data. Data bits on SDA are read as received data on the rising edges of the SCK clock after EN goes HIGH. Only the leading 8 bits on SDA are read after EN goes HIGH and all subsequent input data bits are ignored, but the received data is reflected in SM8134A operation with timing almost simultaneous with the EN falling edge. Conversely, if less than 8 bits are input on SDA, the data is ignored to prevent incorrect operation. All registers are write-only, and their status cannot be read. After power is applied, an internal power-ON reset circuit initializes all registers to logic level LOW in standby mode. However, the possibility exists that there may be insufficient reset time, depending on the VIN input voltage rise time and fall time, so reset mode (0H or EH) should be expressly invoked after power is applied. There is no restriction in the input sequence when setting parameters. However, since the parameters are set in the same order as the data input sequence and the time taken from LED ON/OFF data input to LED dimming data input can exceed the soft start time, it is highly advisable to enter the LED dimming data first. The charge pump circuit, that supplies the LED drive voltage, starts whenever any parameter in address 5H (LED ON register) is set to 1, with the LED drive voltage output on VOUT. Conversely, when all parameters in address 5H are set to 0, all other parameter data settings input after reset are retained in standby mode. The serial interface pins EN, SDA, and CSK are CMOS inputs, thus the input voltage on VIN must be a logic-level voltage and should not be left open circuit (floating). Control Data
Mode selection data M1 MSB M2 Data 1 M3 Data 2 M4 Data 3 D1 Data 4 D2 Data 5 Setting data D3 Data 6 D4 LSB
EN
SCK
SDA
M1
M2
M3
M4
D1
D2
D3
D4
Control data input sequence
I
Mode selection
Mode data Mode M1-M2-M3-M4 0H Reset L-L-L-L 2H DIN1 to 4 dimming L-L-H-L 4H DIN5 dimming L-H-L-L 5H LED ON L-H-L-H EH Reset H-H-H-L Other NPC test -
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SM8134A Mode data "0H": Reset register Mode data "EH": Reset register
Setting data High All system data reset and standby Low D1 D2 D3 D4
Reset mode is selected if EN goes LOW 4 clock cycles after 0H or EH mode select data is input, regardless of when power is applied or the parameter set data bits. When reset mode is selected, all data input previously is reset, thus dimming and control data must be reentered. Mode data "2H": DIN1 to 4 dimming register Mode data "4H": DIN5 dimming register
Setting data 0H 1H 2H 3H 4H 5H 6H 7H 8H 9H AH BH CH DH EH FH D1 Low Low Low Low Low Low Low Low High High High High High High High High D2 Low Low Low Low High High High High Low Low Low Low High High High High D3 Low Low High High Low Low High High Low Low High High Low Low High High D4 Low High Low High Low High Low High Low High Low High Low High Low High DIN1 to 4 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 DIN5 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Unit mA mA mA mA mA mA mA mA mA mA mA mA mA mA mA mA
Note. "H": Hexadecimal Note. Target values only. Current rating accuracy is not guaranteed.
D1 to D4 setting data bits control the LED current in 15 steps. Mode data "5H": LED ON register
Setting data High Low D1 DIN1 to 4 ON DIN1 to 4 OFF D2 - - D3 DIN5 ON DIN5 OFF D4 - -
This register controls the DIN1 to 4 and DIN5 ON/OFF state. Each state is ON when the corresponding bit is HIGH, and OFF when LOW. Each circuit starts when the corresponding bit in address 5H (D1 or D3) is set HIGH, transferring from standby mode. It is recommended that these data settings be held LOW when possible to control current consumption.
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SM8134A
Thermal Shutdown Circuit (Overheating Protection)
The thermal shutdown circuit operates whenever the IC temperature exceeds approximately 170C for whatever reason. VOUT output recommences when the IC temperature falls below approximately 150C. In that case, the setting register is saved.
Under Voltage Lockout Circuit (UVLO)
When a VIN voltage falls below the 1.9V (typ), the under voltage lockout circuit operates, initializing all the registers to logic 0. In this mode, all previous data is reset, thus all dimming and LED control data must be input again.
VOUT Output Circuit Mode Switching
The SM8134A switches between 3 output states: standby mode (standby state), x1.0 mode (VIN through mode), and x1.5 mode (x1.5 charge pump boost). This automatically adjusts the VOUT output to match the drive LED characteristics and reduces the total power dissipation. Switching to and from x1.0 and x1.5 mode occurs automatically in an internal circuit, and cannot be controlled using an external input. Switching to standby mode The internal circuit operating mode switches from x1.0/x1.5 mode to standby mode when Reset resistor (mode data "0H", "EH") was input, suppressing current consumption. Switching from x1.0 mode to x1.5 mode If the LED drive current set by serial interface can be driven without boosting the VIN input voltage, the VOUT output operates in x1.0 mode. In other words, if sufficient current flows even with the LED forward-direction voltage drop "VF", then VOUT is less than 4.9V. Operation in the more efficient x1.0 mode reduces the total power dissipation and extends the battery drive time. And if low "VF" LEDs are used or the LED drive current setting is LOW, the operating time in x1.0 mode is also extended.
1.0 mode (high efficiency)
High VF LED
1.5 mode (low efficiency)
1.0 mode (high efficiency)
Low VF LED High VIN input
1.5 mode (low efficiency)
Low
VOUT mode switching time comparison due to drive LED "VF" variation If the VIN voltage falls or LED drive current set by serial interface increases such that the LED drive current is too low in x1.0 mode, then the LED drive circuit low-current detector operates, the VOUT output is automatically switched to x1.5 mode, and the charge pump boosts the output voltage. This occurs even if only one LED low-current condition is detected among the 5-channel LED drive circuits, thus it is recommended that LEDs have small "VF" variation to optimize the total efficiency.
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SM8134A
VIN input voltage
1.0
1.5 threshold
Low ILED detector
Low ILED detected
(1)
VOUT mode
(2) 1.0 mode 1.5 mode
VOUT output voltage
4.9V
(3)
VIN voltage drop and VOUT output voltage (1) When VIN falls, VOUT cannot overcome the LED "VF" rating, causing insufficient current flows and the ILED low-current signal becomes active. (2) When the ILED low-current condition is detected, the VOUT output circuit switches to x1.5 mode (charge pump mode). (3) Prior to switching to x1.5 mode, the VOUT voltage may be lower than 4.9V but sufficient current is supplied to the LED. If after startup, the LED connected to a DIN pin is switched, the LED connection detector circuit flags an error, and correct mode switching may not occur. If the DIN pin does not control the LED drive current, the low-current detector does not operate and the device cannot switch to x1.5 mode.
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SM8134A Switching from x1.5 mode to x1.0 mode VF increases immediately after the LED current starts to flow, and then decreases as the LED temperature increases due to the heating effect of the current flow. It can take about 10 seconds for the LED temperature to stabilize and for VF to reach equilibrium, and VF may fluctuate more than 200mV. The VF fluctuation is affected by the ambient temperature and LED current setting, and has a large affect on the automatic mode switching voltage tolerances. To counter the effects of VF fluctuation, the SM8134A outputs a mode reset signal once every 1.4 seconds which automatically switches the output mode to x1.0, and then a determination is made whether to make the x1.0 x1.5 mode switch.
1.4sec/cycle Mode reset
(1)
VOUT mode
(2)
1.5 mode 1.0 mode
Mode hold L: hold
min 80s max 200s
ILED detector ignore
(3)
VOUT output voltage
4.9V (4)
Low ILED detector
(5)
Switching from x1.5 to x1.0 mode due to the mode reset signal (1) Mode reset signal is output once every 1.4 seconds. (2) Switching from x1.5 to x1.0 mode due to the mode reset signal pulse. (3) The mode hold time of 200s (max) starts when output switches to x1.0 mode. During this interval, the mode is not switched even if an ILED undercurrent condition is detected. (4) If VIN is low, the VOUT voltage momentarily drops because the boost function stops as a result of switching to x1.0 mode. (5) The ILED undercurrent signal is ignored during the mode hold time, and the mode only switches in response to the detector output after the mode hold time expires.
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SM8134A For example, if the VIN voltage is low and the VOUT output voltage in x1.0 mode does not provide sufficient drive current, then the mode reset will cause a LED undercurrent condition. The LED undercurrent detector circuit will output an LED undercurrent signal immediately after the switch to x1.0 mode, but the output will stay in x1.0 mode and not return to x1.5 mode for the duration of the mode hold time. Consequently, the VOUT output is not boosted during the 85s (min) to 200s (max) mode hold time and the voltage drops and the LED brightness is reduced. However, the LEDs are OFF for a maximum of 200s only, and this is not discernible to the naked eye and thus is not a problem.
1.0
VIN input voltage
1.5 threshold
Mode reset (1.4sec/cycle) Mode hold (H: hold)
VOUT mode (H: 1.5, L: 1.0)
1.4sec
max 200S
VOUT output voltage Low ILED detector (H: low ILED)
4.9V
VOUT drop due to the mode reset single
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SM8134A
STARTUP SEQUENCE
After power is applied to the SM8134A or when a reset input occurs (reset register mode setting), the internal power-ON reset circuit initializes all registers to their default value of 0. Consequently, all required data for LED drive operation must be input using the serial interface. The registers can be addressed in arbitrary sequence. Note that the registers are set in the same sequence as they are addressed.
Example 1. Set LED1 to LED4 to 20mA drive without group setting
Set EN HIGH, input "2AH" using the serial interface, set EN LOW (LED1 to 4 current setting 20mA), set EN HIGH, input "58H", set EN LOW, LED1 to LED4 turn ON after the soft start ends.
Set LED1 to 4 current 20mA EN 2 SDA 0 0 1 0 1 0 A 1 0 0 1 5 0 1 1 0 8 0 0 LED1 to 4 ON
SCK Soft start time 20mA
LED1 to 4
EN = High
Send serial data "2AH" 2: DIN1 to 4 dimming command A: Dimming data (20mA)
EN = Low
EN = High
Send serial data "58H" 5: LED ON command 8: LED1 to 4 ON
EN = Low
Example 1 input waveform
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SM8134A
Example 2. Set LED1 to LED4 to 20mA and LED5 to 120mA drive
Input "2AH" (LED1 to 4 current setting 20mA), "4CH" (LED5 current setting 120mA), "58H" (LED1 to 4 ON) on successive EN cycles using the serial interface. LED1 to LED4 turn ON after the soft start ends. Then input "5AH" (LED1 to 5 ON) and in addition to LED1 to LED4, LED5 turns ON.
Set LED1 to 4 current 20mA EN 2 SDA 0 0 1 0 1 0 A 1 0 0 1 5
LED1 to 4 ON
Set LED5 current 120mA
LED1 to 5 ON
8 0 1 1 0 0 0 0 1
4 0 0 1 1
C 0 0 0 1
5 0 1 1 0
A 1 0
SCK 20mA LED1 to 4 Soft start time 120mA LED5 Soft start time
EN = High
Send serial data "2AH" 2: DIN1 to 4 dimming command A: Dimming data (20mA)
EN = Low
EN = High
Send serial data "58H" 5: LED ON command 8: LED1 to 4 ON
EN = Low
EN = High
Send serial data "4CH" 4: DIN5 dimming command C: Dimming data (120mA)
EN = Low
EN = High
Send serial data "5AH" 5: LED ON command A: LED1 to 4 ON, LED5 ON
EN = Low
Example 2 input waveform
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SM8134A
Example 3. Set LED1 to LED4 to 30mA drive, and then change LED 1 to LED4 to12mA drive and set LED5 to 150mA drive
Input "2FH" (LED1 to 4 current setting 30mA) and "58H" (LED1 to 4 ON) using the serial interface. LED1 to LED4 turn ON after the soft start ends. Then input "26H" (LED1 to 4 current setting 12mA), the current of LED1 to LED4 change to 12mA. Moreover input "4FH" (LED5 current setting 150mA) and "5AH" (LED1 to 5 ON), LED5 turns ON in addition to LED1 to LED4. The total current of LED1 to LED5 should be set not exceeding 200mA.
Set LED1 to 4 current 30mA EN 2 SDA 0 0 1 0 1 1 F 1 1 0 1 5 0 1 1 0 8 0 0 0 0 2 1 0 0 1 6 1 0 0 1 4 0 0 1 1 F 1 1 0 1 5 0 1 1 0 A 1 0 LED1 to 4 ON Set LED1 to 4 current 12mA Set LED5 current 150mA LED1 to 5 ON
SCK 30mA LED1 to 4 Soft start time 12mA 150mA LED5 Soft start time
EN = High
Send serial data "2FH" 2: DIN1 to 4 dimming command F: Dimming data (30mA)
EN = Low
EN = High
Send serial data "58H" 5: LED ON command 8: LED1 to 4 ON
EN = Low
EN = High
Send serial data "26H" 2: DIN1 to 4 dimming command 6: Dimming data (12mA)
EN = Low
EN = High
Send serial data "4FH" 4: DIN5 dimming command F: Dimming data (150mA)
EN = Low
EN = High
Send serial data "5AH" 5: LED ON command A: LED1 to 4 ON, LED5 ON
EN = Low
Example 3 input waveform
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SM8134A
TYPICAL APPLICATION CIRCUIT
In circuits where the SM8134A logic-level inputs would become open circuit (floating) when the microcontroller supply stops, pull-down resistors should be connected to each logic-level signal input.
2.7 to 4.6V C4 4.7F VIN
C1 1.0F C1M C1P
C2 1.0F C2M C2P
Charge pump 1/ 1.5
VOUT C3 4.7F Back Light Max 30mA 4ch
Thermal shut down Output voltage control UVLO Current control & Current detect Control logic
DIN1 DIN2 DIN3 DIN4
SCK SDA Microcontroller EN
DIN5
Pull down GND PGND
Flash Max 150mA
Note. If the driving LEDs are less than 5 pcs, the unused DIN pins should be connected to GND.
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SM8134A
PERIPHERAL PARTS
About the External Capacitors
The best capacitors for use with the SM8134A are multi-layer ceramic capacitors. When selecting a multi-layer ceramic capacitor, only X5R and X7R dielectric types are strongly recommended, since the loss of capacitance in various conditions is less than other types such as Z5U and Y5V. The much loss of capacitance in various conditions may cause the output voltage unstable.
Table. The EIA three digit "TC" code
Lower temperature limit X = -55C Y = -30C Z = +10C High temperature limit 5 = +85C 6 = +105C 7 = +125C 8 = +150C Maximum allowable capacitance change from + 25C (0V DC) F = 7.5% P = 10% R = 15% S = 22% T = +22%/-33% U = +22%/-56% V = +22%/-82% For example : X5R
About the Input Capacitor "C4"
The parts layout of PCB may merely cause the "VOUT" output voltage unstable. In this case, increasing the "C4" input capacitance value or adding another capacitor on the VIN input line is effective to solve the unstable output voltage.
FOOTPRINT PATTERN
3.6 0.1 2.2 0.1 0.5 x 3 = 1.5 0.05
0.
32
0.5 x 3 = 1.5 0.05
3.6 0.1
2.2 0.1
0.25 0.05
0.7 0.1
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SM8134A
Please pay your attention to the following points at time of using the products shown in this document. The products shown in this document (hereinafter "Products") are not intended to be used for the apparatus that exerts harmful influence on human lives due to the defects, failure or malfunction of the Products. Customers are requested to obtain prior written agreement for such use from SEIKO NPC CORPORATION (hereinafter "NPC"). Customers shall be solely responsible for, and indemnify and hold NPC free and harmless from, any and all claims, damages, losses, expenses or lawsuits, due to such use without such agreement. NPC reserves the right to change the specifications of the Products in order to improve the characteristic or reliability thereof. NPC makes no claim or warranty that the contents described in this document dose not infringe any intellectual property right or other similar right owned by third parties. Therefore, NPC shall not be responsible for such problems, even if the use is in accordance with the descriptions provided in this document. Any descriptions including applications, circuits, and the parameters of the Products in this document are for reference to use the Products, and shall not be guaranteed free from defect, inapplicability to the design for the mass-production products without further testing or modification. Customers are requested not to export or re-export, directly or indirectly, the Products to any country or any entity not in compliance with or in violation of the national export administration laws, treaties, orders and regulations. Customers are requested appropriately take steps to obtain required permissions or approvals from appropriate government agencies.
SEIKO NPC CORPORATION
15-6, Nihombashi-kabutocho, Chuo-ku, Tokyo 103-0026, Japan Telephone: +81-3-6667-6601 Facsimile: +81-3-6667-6611 http://www.npc.co.jp/ Email: sales@npc.co.jp
NC0417BE 2006.04
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