So my project involves driving 48 white LEDs in a grid pattern from a single 3.7V lipo cell.
The LEDs will have about a 3V forward voltage at their rated current, so I'd like to avoid simply using a 48 channel linear driver with current sinks. I don't have much room for thermal losses here. Also routing 48 traces in a grid will be a bit of a nightmare, especially if I want to maintain good thermal transfer across the board.
One option I'm looking at is the LED7707, 16 channels with a boost converter, so I can tie the LEDs together in series strings of 3 or 4, and let the IC boost the voltage up for me.
This might be the optimal solution, but since I don't have much experience in the field I'm asking for some advice.
Literally all I need is PWM dimming of the whole lot at once, and a relatively high efficiency (>85%?).
If I can do it without SPI or I2C that'd make things simpler, but I'm sure that's where I'll end up.
Anyone who's done something similar I'd love to hear your solution!
Also, LEDs are rated for about 65mA, so I'm looking at around 10W for the whole lot.