Hello,
I hope some one can help me. I have been doing all day trying to set up my SEPIC using TPS40210. It work fine around 24V input. But if I set it up for high line (40V input) then it will not work at 15V input (low line), it went to OC mode then restart in that loop forever. Just like a tug of war I am so frustrated please some one help. I design for 57V output at about 0.9A. I could do a boost but SEPIC keeps the battery input blocked when the IC in DISABLE mode (work nicely). The frequency is 650khz, R sense is 10mOhm, two inductors are 10uH. capacitor is 10uF ceramic. One exception that I have to connect to large capacitor output (12,000uF). I have 4.7uF at SS pin in series with 10K so the 12,000uF cap charge within 1 second (work nicely). I think the switching freq and R sense somehow mess thing up. Thanks for your help.
Kelvin Le