LM2576 buck regulator: 3 A, up to 40 V in

A classic 3 A step-down switching regulator: fixed and adjustable outputs, input limit, 52 kHz switching and the parts it needs.

By Jignesh Panchal · Sources, testing and AI policy

  • TypePower
  • LevelIntermediate
  • ReviewedNov 2026

The LM2576 is a 3 A step-down (buck) switching regulator in 3.3 V, 5 V, 12 V, 15 V and adjustable versions, with a 52 kHz fixed oscillator, a 40 V input (60 V for the HV version) and ±4 percent output tolerance. It replaces a hot linear regulator with a cooler one, and needs only four external components. Figures are from the Texas Instruments LM2576 datasheet.

Key specifications

Output current3 A
Outputs3.3, 5, 12, 15 V, adjustable 1.23–37 V
Inputup to 40 V (60 V HV)
Switching52 kHz
Standby50 µA typ
Protectioncurrent limit, thermal shutdown

What the datasheet promises

ItemDatasheet value
Output current3 A specified
Fixed outputs3.3 V, 5 V, 12 V, 15 V
Adjustable output1.23 V to 37 V (57 V for the HV version), ±4 percent maximum over line and load
Input voltageUp to 40 V; up to 60 V for the HV version
Switching frequency52 kHz fixed, ±10 percent
Standby current50 µA typical with the shutdown pin used
ProtectionCycle-by-cycle current limit and thermal shutdown
External partsFour components (input and output capacitors, diode, inductor)
PackageTO-220 (5 pin), among others

The datasheet marks the LM2576 as an older design and lists newer converters, such as the LMR51430 and the LM76003, for new products. The LM2576 stays useful because it is common on cheap modules and because its 52 kHz switching is easy to filter.

Using it on a robot

  • Use a Schottky catch diode and an inductor from the datasheet’s selection guide; a wrong diode or inductor is the usual reason for overheating.
  • Place a bulk capacitor on the input, because motors on the same battery cause voltage dips.
  • Set an adjustable module with a meter and no load before connecting a servo or controller.
  • For a similar small module see the LM2596; for a linear alternative at low current see the LM317.

Sources and further reading

Last reviewed: November 2026. Limits are from the Texas Instruments datasheet; modules sold with this chip vary. No price is quoted because it has not been checked.

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