A control circuit for a PWM switching power regulator including an error amplifier and an amplifier filter circuit. The error amplifier has a first input receiving a reference signal, a second input receiving an output sense signal, and an output providing a compensation signal used to control PWM switching. The amplifier filter circuit has an input receiving a ratio-metric tracking signal and an output providing the reference signal to the input of the error amplifier. The control circuit may include a resistive voltage divider for providing the tracking signal. The amplifier filter circuit may be implemented as a transconductance amplifier having an input receiving the tracking signal and an output coupled to a capacitor. The transconductance amplifier may have a relatively small current drive capacity and its output may have a relatively slow and weak response to changes of the tracking signal.