The LM2596 series is a monolithic integrated circuit that provides all the active functions for a step-down (buck) switching regulator, capable of driving a 3A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5V, 12V, and an adjustable output version. Requiring a minimum number of external components, these regulators are simple to use and include internal frequency compensation, and a fixed-frequency oscillator. The LM2596 series operates at a switching frequency of 150 kHz thus allowing smaller sized filter components than what would be needed with lower frequency switching regulators. Available in a standard 5-lead TO-220 package with several different lead bend options, and a 5-lead TO-263 surface mount package. A standard series of inductors are available from several different manufacturers optimized for use with the LM2596 series. This feature greatly simplifies the design of switch-mode power supplies. Other features include a guaranteed ±4% tolerance on output voltage under specified input voltage and output load conditions, and ±15% on the oscillator frequency. External shutdown is included, featuring typically 80 µA standby current. Self protection features include a two stage frequency reducing current limit for the output switch and an over temperature shutdown.
The LM2596 series are monolithic step‑down (buck) switching regulators that deliver up to 3 A of output current with excellent line and load regulation. Fixed‑frequency operation at 150 kHz allows the use of small filter components, and the devices are offered in TO‑220 and TO‑263 packages with various lead configurations.
The datasheet details absolute maximum ratings, electrical characteristics, typical performance curves, and mechanical dimensions. It also includes ordering information for fixed‑output versions (3.3 V, 5 V, 12 V) and an adjustable version, as well as safety notices for life‑support applications.
| Maximum Output Current | 3 A |
|---|---|
| Switching Frequency | 150 kHz |
| Input Voltage Range | Up to 40 V |
| Efficiency (12 V in, 3 A out) | 73 % |
| Standby Current (shutdown pin) | ≈ 80 µA |
The LM2596 operates at a fixed internal oscillator frequency of 150 kHz.
The regulator can supply up to 3 A of output current.
Fixed‑output versions are offered at 3.3 V, 5 V, and 12 V.
The shutdown pin draws about 80 µA in standby mode.