Other Parts Discussed in Thread: ISO7760
Hi,
I have a design using TPS7A7833PWPT in HB mode. Intermittently it powers up and LDO_OUT is 1.7V rather than 3.3V. I suspect it may have to do with me violating the Cldo_in/Cldo_out 10:1 ratio. My circuit values are as follows:
TPS7A78 in HB mode
Cs: 680nF
Rs:330R
Cscin: 330uF + 100nF
Csc1: 1u +100n
Csc2: 2.2u + 100n
Cldo_in: 22u+10u
Cldo_out: 22u+22u+1u+100n
Appreciate if you can...
1. explain the my intermittent 1.7V on LDO_OUT.
2. explain the 10:1 ratio requirement
3. how to calculate hold time for the TPS7A78 in HB mode. I assume on power outage TPS7A78 remains powered by Cscin?
Thanks
tc