Other Parts Discussed in Thread: TPS65185
Hi,
I use the TPS63031 DC/DC Converter at a EPD-Driver-Board (TPS65185 and STM32F405). Unfortunately I always get audible noises.
I measured at the inductor of the DCDC-Converter with an oscilloscope. I detected a frequency of about 1 kHz. Power save is activated. Hence the cause for a
audible noise could be the converter I assume. (The inductor has already been replaced without success). The volume depends on the load. (At 100 mA it is louder than at 10 mA.)
After the TPS63031 I assembled a 10µF elecrolyte capacitor (unsoldering doesn't change the volume).
I pushed with a metal-stick on some capacitors from the rest of the pcb (not DC/DC) and sometimes the volume changed.
- What is the switching frequency for power save mode at the inductor (also about 2.2 MHz)? Can the 1 kHz be possible?
- All the electronic parts I've already used on an older pcb (so i resoldered it, hence two times reflow). I don't think that's the reason
because the MCU and the rest works fine.
I would really appreciate it if you could give me some help respectively some experiences.
Best regards
