On-Chip Condition-Adaptive Δ f 3 EMI Control for Switching Power ICs

With perpetual electrification and highly dynamic operations, modern automotive ICs face unprecedented electromagnetic interference (EMI) challenges. To address such, this article presents a condition-adaptive [Formula Omitted] EMI control for automotive power circuits, which coordinates integral spread-spectrum modulation (SSM) schemes to regulate EMI adaptively in response to drastic condition changes of input voltage [Formula Omitted] and load current [Formula Omitted]. Specifically, a [Formula Omitted] spread control technique steers the [Formula Omitted] spread direction according to [Formula Omitted], while a [Formula Omitted] spread range modulation scheme adjusts the [Formula Omitted] range according to [Formula Omitted]. Meanwhile, a [Formula Omitted] adaptive multi-rate (MR) SSM scheme prevents spectrum overlap spikes. With the three distinct [Formula Omitted]-focused control modules working cohesively, we name the overall EMI control as the [Formula Omitted] EMI control in this work. In addition, to avoid high-energy EMI from entering the audible frequency range, a modulation frequency [Formula Omitted] envelope tracking scheme is also developed. Demonstrated in an automotive-use GaN switching power converter, this work was fabricated using a 180-nm HV BCD process. It auto-extends [Formula Omitted] from 10% to 32% and reduces EMI by 17.2 dB to counteract [Formula Omitted] elevation from 200 mA to 1 A. Meanwhile, it can down-spread [Formula Omitted] adaptively by the MR-SSM with a 16.3 dB reduction in response to a [Formula Omitted] increase from 12 V to 24 V without causing overlap spikes.