TPS7A4701-EP: TPS7a4701 with adjustable output

Hey Jon,

I have tested this in TINA and not seen the behavior you are describing.

Have you downloaded the model from the -EP version?

Hi Daniel

Thanks for your efforts. I haven't simulated the design, as there didn't seem much that could go wrong. I tried another part but get the same behavior. The only other thing I can think is that it could be something to do with the pad. I haven't soldered the pad as I just hand soldered the device with an iron. Do you think that would make any difference?

Thanks

Jon  

Hey Jon,

My apologies I thought this was a simulation issue.

Can you please provide waveforms of:

1. Voltage at the input pin
2. Output voltage behavior you are seeing

I would also suggest perhaps adding more capacitance.
What is the ESR of your output capacitors?

Thanks,
Daniel

Hi Daniel

The input and output voltages look fine (just flat lines). The device is behaving a bit better now, although the output voltage seems to be creeping up over time. It started at about 23.75V and then slowly went over 23.8V and carried on climbing. The output capacitors I am using are :-
GRM21BR6YA106ME43L

Thanks
Jon

Hey Jon,

If you continue to have problems, try adding more output capacitance.

Also do you have the LDO loaded at all?
Often drawing a small amount of current will help with these issues.

Thanks,
Daniel