MAXREFDES1196

説明

The MAXREFDES1196 is a DC-DC boost power supply that delivers up to 4A at 24V from a 10V to 18V supply voltage. It is designed for equipment that needs a high-power, 24V output voltage that is generated from a 12V DC bus.

The MAXREFDES1196 employs techniques that use the boost regulators to generate voltage higher than input voltage. This document explains how the MAX17499B current-mode PWM converter can be used to generate 24V from 10V to 18V input voltage.

The MAX17499B current-mode PWM controller contains all the control circuitry required for the design of wide-inputvoltage isolated and nonisolated power supplies. The MAX17499B is well suited for low input voltage (9.5VDC to 24V_DC) power supplies. An input undervoltage lockout (UVLO) is provided for programming the input-supply start voltage and to ensure proper operation during brownout conditions. An open-drain UVLO flag output with 210μs internal delay allows the sequencing of a secondary-side controller. The input-supply start voltage is externally programmable with a voltage-divider. A UVLO/EN input is used to shut down the devices. Internal digital softstart eliminates output voltage overshoot. The switching frequency for this IC is programmable with an external resistor. The MAX17499B provides a 75% maximum duty-cycle limit. This device is available in 10-pin μMAX^® package and is rated for operation over the -40°C to +125°C temperature range.