As described in
Section 7.3.8, the NR/SS cap affects
both the total noise and the soft-start time. The recommended value for a 5-ms
soft-start time and good noise performance is 470 nF. The maximum NR/SS cap is 3.3 μF
for a start-up time of 35 ms. Values greater than 1 μF have minimal improvement in noise
performance. Use
Equation 9 and
Equation 10 to
calculate the soft-start time based on desired soft-start time or the chosen capacitor
value.
Equation 9. Equation 10.