SLUU180B January 2022 – February 2022 TPS40070 , TPS40071
The TPS40071 incorporates voltage mode control with feedforward compensation to minimize gain variations with a variable supply voltage. A type-3 compensation circuit is used to provide two zeroes and three poles as detailed below.
The power circuit LC double pole corner frequency, fC, is found to be 10.6 kHz, and the output capacitor ESR zero occurs in the vicinity of 1.1 MHz. The first pole is located at placed at the origin to improve dc regulation.
The first zero is placed at 758 Hz:
The second zero is selected to be near the LC corner frequency at 10.4 kHz:
The second and third poles are placed at 192 kHz and 194 kHz to roll off the high frequency gain: