As described in
Section 6.3.8, the NR/SS cap affects
both the total noise and the soft-start time. The recommended value for a 5ms soft-start
time and good noise performance is 470nF. The maximum NR/SS cap is 3.3μF for a start-up
time of 35ms. Values greater than 1μF have minimal improvement in noise performance. Use
Equation 7 and
Equation 8 to
calculate the soft-start time based on desired soft-start time or the chosen capacitor
value.
Equation 7.
Equation 8.