Dual-Phase Buck Controller Manages Graphics-Card Demands

Bolstered by pulse-width-modulation (PWM) video-identification dynamic-output control, the AP3958A dual-phase synchronous-rectified buck controller helps assure fast, high-response required by inherently large variations in GPU and CPU core power-supply output loading. The device, developed by Diodes Inc., includes a PWM controller, two MOSFET drivers with internal bootstrap diodes, channel-current balance, and protection features in a low-pin-count U-QN4040-24 package. Targeting 12-V systems, it delivers up to 60-A output current and harnesses external compensation to minimize output-voltage ripple and enhance transient response. Lossless R_DS(ON) current sensing maintains accurate phase-current balance, while inductor current-sampling provides a dependable current limit. A power-save mode, which enables the controller to switch automatically between dual- and single-phase operation when subject to light loading, boosts efficiency. Protection functions include overcurrent, overtemperature, and undervoltage/overvoltage. Also incorporated are an adjustable soft-start, adjustable operating frequency selection, and power-good and enable control.

DIODES INC.