Hello,
I wish to drive between 5-7 RGB LEDs in a portable application (5 - 7 x RGB LEDs = 15 - 21 channels). Only one will be active at a time - perhaps 10-12mA while active (sometimes the single LED will be flashing, other times perhaps continuous 10mA). The battery is a LiIon rechargeable with limited capacity (perhaps 50mAh).
I therefore need an LED driver that has very low active current consumption.
My initial thought was the TLC5946 (16 chan) or 5947 (24-chan), both of which can drive 10mA/channel easily. Also, the 5x5mm packages are probably acceptable (although it would be even better to find smaller). However, reading the datasheet, perhaps they are too high power (also they seem to be recommended for non-portable applications)
A couple of questions:
1) It's not clear what the active current consumption of the driver (not including the LED) will be in a typical situation - for example driving a single LED @ 10mA. I could live with up to 1mA (+10mA for the LED = 11mA total).
2) Does TI have a superior solution (16/24 channel) for portable applications (small size, lower active current, small package)?
3) Should I be considering driving the RGB LEDs directly using GPIO from my TI MSP430? I do not believe the voltage from a LiIon is high enough and I'd need a boost converter (at least for 2 of the 3 channels of RGB), and then I may have a unit-unit variation due to unit-unit VF variation (which constant current driving should mostly resolve, thus my interest in drivers).
Thanks in advance.
