Other Parts Discussed in Thread: TPS923655
Tool/software:
I’m currently working on a backlight driver board using the TPS923655DMTR, I’ve configured the board to use boost and buck-boost mode.
I’ve tested the device in boost mode with a Vin of 12V and the device is close to working as the correct voltage is being outputted under load and no-load conditions, the OVP is correct to what I’ve calculated it to be (around 40V).
I’ve also tested the device shorting ADIM and PWM to VCC
However, the current draw to the device is erratic, It starts at about 60mA and after 3 to 5 seconds its jumping between 100 and 200mA even when there’s no load, and the IC does get hot? I can’t see what’s causing this issue.
I’ve made my design in line with the design of the TPS923655DMTREVM boost circuit on page 14 of the attached TPS923655DMTREVM.pdf and that of the boost circuit on page 21 of the tps923655.pdf
I’ve tried also varied FSET and TEMP resistances as a last-ditch attempt to rule everything out but It’s made no difference.
