I review a datasheet, and I found the different
input voltage of the chip has the different load
transient result :
High VIN --> VOUT undershoot is small
Low VIN --> VOUT undershoot is big
Because the rate at which you can change the inductor
current, dI/dt, is VIN/L. The loop "winds up" trying, as you
can see from the undershoot followed by a lesser overshoot
in that case. With adequate VIN the loop is more stable.
You're trying to "catch" the load-step from a standing
start, so you need all the acceleration you can get.
VIN determines acceleration, so to speak.
Do you mean a high VIN get a faster loop response?
==>The following is my idea:
That because the voltage of the inductance is smaller when VIN
is a high value and the target VOUT doesn't change.