Synchronous buck converters feature innovative noise reduction

Diodes Incorporated has released two highly integrated synchronous buck converters that ease circuit design in automotive power systems with its Power Good output and its creative EMI mitigation for noise-sensitive applications.

The AP63356Q and AP63357Q are 3.5A converters offering an input voltage range of 3.8V to 32V. Using peak current mode control as well as high-side and low-side power MOSFETs on-chip, the converters reduce external components to minimise BOM costs and board size.

Both devices offer a Power Good indicator with an internal 5MOhm pull-up resistor valuable for power sequencing. To also aid sequencing, their enable pin provides accurate voltage thresholds, which enables adjustment of the input voltage device power-on and UVLO. The high-voltage capability of the EN pin enables direct connection to VIN to simplify the auto-start of the device. When disabled, the converter draws only 0.6µA shutdown current typical.

The AP63356Q functions continuously in PWM mode at the nominal 450kHz switching frequency for all loads. The AP63357Q shifts to PFM mode at light loads, keeping efficiency as high as 86% at 5mA load and drawing quiescent current of only 22µA under no load.

Both devices feature an LDO operation, which maintains their output-voltage regulation as the input decreases to a level near the output voltage. Built-in protection features comprise output UVP, cycle-by-cycle peak current limit, and thermal shutdown. The protection features, as well as with 40V (for 400ms) input voltage surge withstand capability, allow the devices to deliver a robust Automotive POL solution.

The devices are qualified to AEC-Q100 Grade 1, support PPAP documentation, and are manufactured in IATF 16949 certified facilities. The devices are each available in a 3mm x 2mm V-DFN3020-13 (SWP) package with wettable flanks to assist in automated optical inspection.