Aspects of the disclosure provide a circuit that includes a switch control circuit and a timing control circuit. The switch control circuit is configured to enable/disable a pulse width modulation (PWM) switch control to a regulator to transfer power to a load. The timing control circuit is configured to enable an analog to digital converter (ADC) to convert an analog signal to a digital stream when the PWM switch control is disabled in order to reduce noise in the digital stream due to switching activities in the regulator.