This paper proposes a zero output ripple buck converter for low noise applications. Unlike the conventional zero ripple converter which requires perfectly matched inductors, the proposed converter uses a novel inductor mismatch compensation technique to achieve perfect ripple cancellation. In order to prevent the loop instability due to inversion of PWM signal in the ripple cancellation path, a split PWM controller is used. Implemented in 180nm CMOS process, the proposed converter achieves simulated output ripple of less than 300µV for the entire range of duty cycle (0 to 100%) with peak efficiency of 93.5% for the load current of 0.1-1A at 2.5MHz switching frequency. An undershoot/overshoot of 86mV/56mV with settling time of less than 3.5µS was achieved when a load step of 0.5A/50ns is applied at the output. © 2021 IEEE