The LM22674 is National Semiconductor's 500mA single-chip step-down switch power supply controller, which integrates the constant voltage controller, PWM generator, error amplifier, current detector and other functional circuits. It is suitable for power supply design with few external components.
The LM22674 series provides a monolithic step‑down (buck) switching regulator capable of delivering up to 500 mA with excellent line and load regulation. It integrates a low‑ON‑resistance N‑channel MOSFET, precision enable pin, thermal shutdown, and current limiting, all in a compact PSOP‑8 exposed‑pad package.
Designed for industrial control, telecom, embedded and automotive applications, the device operates from 4.5 V to 42 V input, switches at a fixed 500 kHz frequency, and achieves efficiencies greater than 90 %. The SIMPLE SWITCHER® concept and National’s WEBENCH® design tool simplify layout and component selection.
| Input voltage range | 4.5 V to 42 V |
|---|---|
| Switching frequency | 500 kHz |
| Efficiency | >90 % |
| Package | PSOP‑8 (Exposed Pad) |
| Operating temperature range | -40 °C to 125 °C |
| Enable pin pull‑up current | ≈6 pA |
| Typical quiescent current (EN=0 V) | 3.4 µA |
The regulator switches at a fixed frequency of 500 kHz.
The device is rated for a maximum input voltage of 42 V.
It is supplied in a PSOP‑8 package with an exposed pad.
Typical efficiency is greater than 90 %.