Other Parts Discussed in Thread: LM3409, LM3409HV,
Hello
We are using the LM3409HV with shunt FET in two commercial products. We now need higher power but are running into heat issues with the LM3409. The sense resistor seems to be the main cause of efficiency loss, but the diode and PMOS also contributes.
We are looking for a driver that can power a rather large bank of LEDs. Vin is 48 volt, Vf is 42 volt and the If is 3-5A. We are doing color mixing with 5 colors and the PWM duty cycle needs to be very precise. We are using 12 bit resolution. (I.e we are using 5 buck drivers to power the five banks of different color LEDs and controlling the duty cycle of each color to produce a final color or spectrum.)
It looks like TPS92641 with shunt FET might be a suitable part. Due to space restrictions on the emitter board we do not have room for separate return paths for the five led banks. High side sensing would allow for that.
1. Is there a way to adapt the TPS92641 for high side sensing?
2. Is there a different part better suited for this?
Thanks
/Morten