Abstract:
In spread-spectrum electromagnetic interference (EMI) suppression, transmitter (TX) frequency is continuously modulated with fast speed. Conventional receiver (RX) autotu...Show MoreMetadata
Abstract:
In spread-spectrum electromagnetic interference (EMI) suppression, transmitter (TX) frequency is continuously modulated with fast speed. Conventional receiver (RX) autotuning methods cannot be used because of their slow response speed. Another limitation of conventional autotuning is their low efficiency if the incoming TX frequency is deviated far from RX nominal frequency (i.e., boundary of tunable range), even if the RX is reconfigured to tuned resonance. To solve the issues, the proposed PWM-tuning RX achieves constantly high efficiency even at the boundary of frequency tuning range. The proposed topology boosts the reflected resistance, thereby increasing the TX-to-RX efficiency compared to traditional variable tunings. We also propose an RX feedback loop which can track the fast-varying TX frequency and tune the RX capacitor accordingly. The step-response of proposed loop is fast (0.1 ms) in order to be suitable for spread-spectrum EMI suppression. The tuning mosfet achieves soft switching both at turn-on and turn-off. A simple grounded gate driving can be used. The measurement results show that the proposed ATR can improve the overall power transfer efficiency (PTE) by 7%–12% point for spread-spectrum ranging from 108 to 137 kHz, enabling 19.9 dB EMI suppression.
Published in: IEEE Transactions on Industrial Electronics ( Volume: 70, Issue: 1, January 2023)