Other Parts Discussed in Thread: TLC5951, TLC5929
Hello,
I'm using the TLC5926IPWPR in a design to control LEDs. In this application I control 15 LEDs. One for each channel. Only one LED is ever on at any given time.
In my application I am finding that I need a much larger dynamic range in current. The TLC5926IPWPR says I need 5mA minimum. So I designed it to have 5mA to 59mA for the full 0x00-0xFF register range.
I may need a much larger range like 400uA-50mA or 100uA to 50mA or something around there. . I would like to look at all options.
Questions:
1) Do you have a device like the TLC5926IPWPR that has a wider operating range?
2) Is there something that I could add externally that could force a high or low range? For example, when this external circuit is disabled, I have my normal 5mA to 59mA range, but when external circuit is turned on, it can have 400uA to 5.9mA? For example, a resistor in parallel with an LED will take away some of the 5mA on a channel and the rest will be through the LED. The problem with that is now the LED current is not deterministic, I set a channel to 5mA, but the current through the LED and resistor will change as the LED forward voltage changes (with temp or age, etc). It's not really a constant current source anymore.
3) Why does the TLC5926IPWPR have a minimum current of 5mA? Not that it would solve my issue if it could go lower because it need a bigger range and lower values.
