One of our customers is have an issue with the TPS61170.
I've taken measurements with the TPS61170 and I don't think this part isn't working as it should. We have 5 V input voltage, the output resistors are set so that about 24 V output voltage comes out. I want to reduce this output voltage to 12 V with the PWM. PWM 20 kHz, duty cycle 50%. Unfortunately, this doesn't work at all as desired. It comes out about 12 V, but usually switches on and off with the PWM frequency of 20 kHz. Firstly, this leads to an enormous ripple and secondly, the maximum performance is reduced by 50%. If you do a PMW at 95 kHz, 50% duty cycle, it seems to be working properly. However, according to DB, a PWM between 5 kHz and 100 kHz should work. What's going on here?
Measurement of the current on the coil with 20kHz PWM, Vin 5V, Vout 12V:
Thanks and Kind Regards