Other Parts Discussed in Thread: TPS61176, TPS61500
Customer Question:
This product needs to drive two strings of high brightness LEDs from a single cell lithium ion battery.
The technical requirements:
1) Vin 3.0 – 4.2V. Maximum Vf of the LED strings is 34V.
2) Two strings in the product in total. It would be ideal to drive them both from one chip.
3) Each LED string needs to be driven with a constant 200 mA.
4) No dimming is needed.
I’ve looked at a few of the TI backlight drivers so far; mainly the TPS61169. Unfortunately the 1.2A limit of the internal switch doesn’t allow me to run the LED’s at the full 200 mA. Is there a similar part with an external switch possibly? Or another part in the TPS family that I should be considering?
I’ve also considered the TPS61176 by combining string inputs together. The part lists the maximum current total for its six sinks as 200 mA; is it possible to connect all six together to drive a single string of these LEDs at 200 mA? The datasheet (http://www.ti.com/lit/ds/symlink/tps61176.pdf, figure 19) only shows combining two sinks together at a time.
