Maximum Output Constant-Current
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Question

What is the maximum output constant-current per channel?
What should I use as ?

I know that the maximum output constant-current per channel will be when that channel is full brightness, ie the uniformity dot correction bits are set to maximum, as well as the pixel brightness greyscale bits are set to maximum.

My selected RS-1515MBAM LEDs can sink an absolute maximum of forward current on the red channel, and on each of the green and blue channels.

I will not consider the maximum forward current of alternative LED packages here, as it will be trivial to change a single resistor in the event that I need to change 735 LEDs.

I will therefore design for a maximum per-channel constant sink-current of , such that the LED drivers implicitly aid in ensuring that the LED absolute forward current limit is met.

As per the TLC5951DAP datasheet, this requires an external resistor given by

where is the internal reference voltage on the IREF pin, typically .

Schematic Note

Have an extra DNF parallel resistor for in case I want to increase the current limit (ie have higher brightnesses)—by lowering the , I get finer brightness control over each channel

Question

Ideally I would start on the maximum current limit, and optionally drop it down—this would require me to be able to increase though (NF parallel resistor and desolder?)

Maximum Current IREF

Select the maximum constant sink-current value to be greater than the maximum continuous output current of each channel.

Maximum Output Constant-Current...

Maximum Output Constant-Current
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