リファレンスガイド

説明

The MAXREFDES1257 is a DC-DC boost power supply that delivers up to 500mA at 48V from an 8V to 14V supply voltage. It is designed for equipment that needs a high-power, 48V output voltage that is generated from a 12V DC bus.

The MAXREFDES1257 employs techniques that use the boost regulator to generate a voltage higher than the input voltage. This document explains how the MAX17597 peak-current-mode controller can be used to generate 48V from 8V to 14V input voltage.

The MAX17597 offers input thresholds suitable for low-voltage DC-DC applications (4.5V to 36V). The MAX17597 implements a boost converter and contains a built-in gate driver for external N-channel MOSFETs.

The MAX17597 houses an internal error amplifier with a 1% accurate reference, eliminating the need for an external reference. The switching frequency is programmable from 100kHz to 1MHz with an accuracy of 8%, allowing optimization of magnetic and filter components, resulting in compact and cost-effective power conversion. For EMI-sensitive applications, the MAX17597 family incorporates a programmable frequency dithering scheme, enabling low-EMI spread-spectrum operation.

Users can start the power supply precisely at the desired input voltage, implement input overvoltage protection and program soft-start time.

A programmable slope compensation scheme is provided to ensure stability of the peak-current-mode control scheme. Hiccup-mode overcurrent protection and thermal shutdown are provided to minimize dissipation in overcurrent and overtemperature fault conditions.

The MAX17597 provides a 95% maximum duty-cycle limit. This device is available in a 3mm x 3mm TQFN package and is rated for operation over the -40°C to +125°C temperature range.