Best schematic for driving 12V LED strips with TLC5940 with a possibility to PWM

Other Hardware LEDs and Multiplexing
7

Grumpy_Mike:
You need a base resistor in that PNP transistor.

The outputs of the TLC5940 are sink only. Therefore you need a pull up resistor to 5V.

I would also make R1 between 1K and 10K.

  1. Isn't the TLC constant current out? You could set that to 1mA or so.

  2. Could add a 10k bleed resistor to VCC. Needed? See TLC datasheet for output off leak current.

  3. That would make PWM/switching slower. Wouldn't go more than 1k.

Leo..