lm2576 is a switching regulator chip launched by micrel company. the chip works at a fixed frequency of 52 khz and has three fixed output voltages of 3.3v, 5v and 12v. the adjustable version has an output voltage range of 1.23v-37v. the chip has excellent input voltage range and load regulation. it is easy to use and has few external components, making it suitable for the design of switching power supplies
The LM2576 series provides a simple, high‑efficiency step‑down switching regulator. Fixed versions deliver 3.3 V, 5 V or 12 V, while adjustable versions cover 1.23 V to 37 V. The device operates from 4 V to 40 V input and can supply up to 3 A with excellent line and load regulation.
The regulator includes internal frequency compensation, a 52 kHz fixed‑frequency oscillator, and protection features such as cycle‑by‑cycle current limiting and thermal shutdown. It is offered in 5‑lead TO‑220 and TO‑263 packages and requires only a few external components for typical applications.
| Maximum Output Current | 3 A |
|---|---|
| Input Voltage Range | 4 V to 40 V |
| Fixed Output Voltages | 3.3 V, 5 V, 12 V |
| Adjustable Output Voltage Range | 1.23 V to 37 V |
| Oscillator Frequency | 52 kHz |
Typical efficiency is about 80 % and can exceed 82 % for the adjustable version.
It provides cycle‑by‑cycle current limiting and thermal shutdown for full fault protection.