A synthetic ripple generator that controls conversion of an input voltage to an output voltage while maintaining a relatively constant switching frequency including a ripple capacitor and resistor, a transconductance amplifier circuit, an output error circuit, a frequency control circuit and a hysteretic comparator. The ripple capacitor and resistor develop a ripple voltage. The transconductance amplifier circuit switches, based on a PWM signal, between charging the ripple capacitor based on the input voltage and discharging the ripple capacitor based on the output voltage. The output error circuit provides a compensation voltage indicative of an error of the output voltage. The frequency control circuit develops a ripple window voltage relative to the compensation voltage to adjust switching frequency. The hysteretic comparator has a first input receiving the ripple voltage, a second input receiving the compensation voltage, a third input receiving the ripple window voltage, and an output providing the PWM signal.