ABSTRACT Electromagnetic interference (EMI) from sharp switching transitions poses a critical challenge in light‐load single‐input dual‐output (SIDO) DC–DC converters, often requiring bulky input filters and degrading efficiency under variable loads. This paper presents a patterned pulse‐skipping modulation (PSM) strategy, implemented on a Kintex‐7 FPGA and validated on a MOSFET‐based SIDO buck converter. We analyze EMI over load currents of 50–200 mA using equal‐charge/skip (2:2), unequal‐charge/skip (5:2), and sequential one‐charge/ skip patterns under the strict voltage regulation constraints typical of IoT systems. The sequential 1:4 pattern suppresses the 200‐kHz switching‐frequency component to the noise‐floor‐limited level (approximately −104 dB), while maintaining peak‐to‐peak output ripple between 50 and 100 mV and suppressing higher order harmonics by over 30 dB. Analytical modeling attributes this spectral suppression to deterministic cancellation of the switching‐frequency component and controlled spectral redistribution of the inductor current, demonstrating a favorable trade‐off between EMI mitigation and conversion efficiency. The proposed patterned PSM delivers a compact, modulation‐based EMI mitigation technique for multirail converters requiring precise voltage regulation.
Gupta et al. (Thu,) studied this question.