TPS54160A: TPS54160A soft time

Hello Linda,

Soft start charging current is specified as being only 2 uA. Some probes draw enough current to affect soft start time. Could you measure output voltage startup again with no additional circuitry or probes connected to the soft start pin?

Using the power good pin as an indicator of soft start being complete should give good results in this case.

Regards, Robert

hello Robert,

thanks for your reply , this issue have been closed, but they want to know about this SS capacitor selector question, this Cap must select in below range? if they select it out of this range, what's happen for the system or circuit? or it maybe isn't Strict requirements for it.

if they use the 470nf with 20% accuracy, it is ok? they need make sure it.

HI TI Team，

any feedback about above question, thanks.

Hello Linda,

Yes, a rated value of 470 nF is OK. This specification was written with capacitor tolerance in mind.  If the value for your capacitor exceeds 470 nF due to tolerance, the slow start time may not increase proportionally due to noise.  This will not affect your circuit unless a significantly longer slow start time is wanted as a typical slow start time. 

Regards, Robert