TLC5947: PWM Frequency

Mikael Movsisyan

Prodigy 80 points

Part Number: TLC5947

Hello,

What is the frequency of the 12-bit PWM used for dimming in the TLC5947?

Thank you,

Mikael

over 3 years ago

0 Mikael Movsisyan over 3 years ago

Prodigy 80 points

One more question, can this constant current sink support RGB LEDs, since Vf will be different? My plan is to use a series resistor to ensure Vout is <= 2.0V.

0 Frank Qiu over 3 years ago in reply to Mikael Movsisyan

TI__Genius 15776 points

Hi Monet, could you help in this case.

+1 Monet Xu over 3 years ago in reply to Mikael Movsisyan

TI__Expert 8335 points

Hi Mikael,

For question 1, you can refer to the page 13 in the datasheet. The TLC5947 is integrated with a 4-Mhz internal oscillator. and the 12-bit GS data include 4095 steps. So the frequency of the 12-bit PWM is 4MHz and the frequency of LED is 4MHz/4095.

For question 2, the current sink can support different VF LEDs and you can series a resistor for decreasing power.

Best Regard

Monet Xu

0 Mikael Movsisyan over 3 years ago in reply to Monet Xu

Prodigy 80 points

Hi Monet,

Thank you very much!

Best,
Mikael

0 Monet Xu over 3 years ago in reply to Mikael Movsisyan

TI__Expert 8335 points

Hi Mikael,

If there is more question please contact me again. If this solves your problem, please click 'resolved'.

Best Regard

Monet Xu

Power management

Power management forum

TLC5947: PWM Frequency