Hello,
We are using TPS40210 in SEPIC regulator. We have an issue that output voltage is not increasing without interruption. We have 6mF capacitor buffer on the output, and boost voltage from 24V to 32V.
Se purple line V_32V_BUF on the flowing scope. Yellow line is voltage cross sensing resistor on ISNS pin, Cyan line is current to the output capacitors. Green is voltage on SS pin.
I was tring increase capacity on SS pin for soft start from 220nF to 1uF. But it doesn't help just increased time between first and second start. What other should I try to avoid this behavior? Thanks for any idea.
Schematic:
