Other Parts Discussed in Thread: LM3481, BQ25606,
Trying to maintain backward compatibility with the power source and downstream power requirements we have designed a new power board which takes a 12V DC input into the BQ25606 to manage power/charge with a LiPo battery back. From the BG25606 we go into the TPS61230 to get 5VDC. From there we go to the final stage - LM3481 to get 24VDC. We're having issues with the 5V output being very noisy and not able to hold 5V with even a small current draw (<100mA). We've done tested a few things and the LM3481 is not getting anywhere close to 24VDC output either, only showing between 10-12VDC.
Initially we could the Webench design called for double output capacitors on both 5V and 24V stages and only single caps were used in the PCB. But soldering on more caps didn't solve the issue. We believe we have sufficient grounds planes and shielding, etc. Trace size could be a concern for the current draw, but shouldn't affect the voltage and noise levels....
Schematics:
