This paper introduces a boost converter in conjunction with a synchronized switch mode Active Electromagnetic Interference Filter (AEF), which reduces energy storage requirements compared to passive EMI filters. The proposed AEF, operating at a frequency of 30 MHz prevents additional EMI into the system as its operational frequency lies beyond the typical range of conducted EMI. The AEF is realized using a synchronous buck converter with a series resonant tank and the current configuration is designed to counteract the ripple component of the boost converter. We implemented the duty-controlled switching in the proposed AEF using high-speed analog circuits to generate the filter's pulse width modulated (PWM) signals. The proposed methodology analytically models the AEF circuit to control the current magnitude to a desired level in an open loop to reduce the complexity of the circuit. The AEF is employed in a 12V-to-24V boost converter switching at 150 kHz and has been found to attenuate the fundamental ripple component by 23 dB effectively reducing the volume of AEF by 47% compared to that of passive counterpart.
