UCC28810EVM-003: LED driver

Amol Dahake

Prodigy 90 points

Part Number: UCC28810EVM-003

HI TI,

I am working on UCC28810EVM-003: LED driver EVM board I have doubts mentioned below,

1. How PWM frequency and duty cycle is related to the output constant current.

2. How we are getting constant current.

over 2 years ago

0 Amol Dahake over 2 years ago

Prodigy 90 points

I am using external microcontroller for PWM signal to dimming the LED

0 Ray DiCecco over 2 years ago in reply to Amol Dahake

TI__Genius 10555 points

Hi Amol,

*Corrected*: Without the PWM dimming, the DC output of the buck stage is fixed. By using a PWM to enable/disable the buck controller, the output current is lowered in (inverse) proportion to this enable/disable duty cycle. This current is fed through the half-bridge transformers T2 & T3 to the LEDs.

Are you not getting a constant current on the output?

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UCC28810EVM-003: LED driver