This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
Hello,
there is an issue regarding the soft-start of TPS56121.
Requirement: 3.3V with soft-start time < 400µs
=> 22nF soft-start-C like in datasheet is not applicable; I have to use 4.7nF or 5.6nF (regarding all tolerances C_SS, V_FB, I_SS)
Here you see the measured waveforms:
My concern is the peak in voltage at the beginning of the calibration phase. I did not see this peak when soft-start-C was 22nF!
=>
- does this peak cause any trouble?
- how high may this peak be (here it's about 2.4V; OK < abs max ratings @ EN/SS = 7V BUT > 1.3V = soft-start voltage level ; start of ramp)?
Many thanks
regards
Udo