Design of Adaptive On-Time GaN DC-DC Converter with Active Gate Driving for Automotive System

초록

The proposed paper introduces a single-stageGallium Nitride (GaN) DC-DC converter employing adaptiveon-time (AOT) hysteresis control including an active gatedriving bootstrap (BST) gate driver. To achieve optimal onecycletransient response during load variations, it incorporatesa sample and hold-based load detecting transient enhancer forprecise detection of load changes and accurate control of ontimeextension. Additionally, an active gate driver utilizing adv/dt detector is designed and applied to independently controldv/dt and di/dt, mitigating the trade-off betweenelectromagnetic interference (EMI) and switching loss. Theconverter was fabricated using a 0.18-μm HV BCD 1P6Mprocess with a total chip area of 1.05 × 0.80 mm. It converts upto 60-V input down to 3-V and operates in the frequency rangeof 0.95–9.5 MHz. Designed to support a wide automotivebattery voltage range from 7 to 60 V, post-layout simulationsshow the output voltage ripple is as low as 2.9 mV at 12 to 3 Vconversion and 4.2 MHz switching frequency, achieving amaximum efficiency of 91.3%.

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