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Max Output current LED Driver TLC5927

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guardspecialone

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Maximum Output Current: LED Driver TLC5927

Hello

I will be using LED driver TLC5927. I will be driving 16 LEDS and each led will consume around 30mA, thats total 30mA*16 = 480mA

I was reading datasheet and it says output current: 120mA

Device Topology: Constant Current
Driver Case Style: SSOP
Input Voltage Max: 5.5V
Input Voltage Min: 3V
No. of Outputs: 16
No. of Pins: 24
Output Current: 120mA
Output Voltage: 17V

Q1: Is this 120mA on each output or this is maximum current on all 16 outputs?
Q2: This driver has OE pin (output enable/disable). Can I connect CCP from MCU to this pin and use it to controll brightness with PWM? Is this safe or not recommended?
 

I think its each channel can be up to 120mA...but you will need to do power calc to check temperature of chip.

with 16 leds, I would just put them in series and drive them off a constant off time led driver, eg HV9910B OR LM3421 , ETC

there SHOUDL BE A PWM Dimming input for pwm dimming, I wouldn't ue the en/dis pin unless the d'sheet specifically says so
 
TLC5927 current is 120 mA maximum per channel, or 1920 mA in total. You can dissipate about 3 W with the PWP thermally enhanced package, you see that the highest current is only possible with a carefully matched LED supply voltage. But 30 mA is well in the comfort zone.

The maximum output current is programmed by a resistor, in addition you have a wide range of digital current programming trough SPI. PWM is another option and the usual way to set the pixel brightness in LED video displays built with TLC5927 and similar drivers.
 
FvM said:
TLC5927 current is 120 mA maximum per channel, or 1920 mA in total.
Click to expand...

Good, thank you

treez said:
I would just put them in series and drive them off a constant off time led driver, eg HV9910B OR LM3421
Click to expand...

Thanks! I never realized how those LED drivers (with 1 output) works. I dont see how can I control individual leds with LM3421 and my PIC?
 
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