# TPS54331 buck converter: 3.5 to 28 V in, 3 A out

> A 3 A step-down converter at a fixed 570 kHz for 12 V and 24 V robot rails: input range, reference, protections and layout notes.

Canonical: https://roboticsengineering.in/components/tps54331-buck-converter/ | Published: 2026-11-03 | Updated: 2026-11-03

**The TPS54331 is a non-synchronous buck converter with an 80 mΩ internal switch that takes 3.5 to 28 V in and delivers up to 3 A, with the output adjustable down to 0.8 V.** It switches at a fixed 570 kHz and has a pulse-skipping Eco-mode for light loads. It is the design-it-yourself step above the [LM2596](https://roboticsengineering.in/components/lm2596-buck-converter/) and [LM2576](https://roboticsengineering.in/components/lm2576-buck-regulator/). Figures are from the Texas Instruments datasheet SLVS839H.

## Key specifications

| Input | 3.5–28 V |
| --- | --- |
| Output current | 3 A |
| Output | adjustable down to 0.8 V |
| Switching | 570 kHz fixed |
| Shutdown | 1 µA typical |
| Package | SOIC-8 / SO PowerPAD |

## What the datasheet promises

| Item | Datasheet value |
| --- | --- |
| Input voltage | 3.5 to 28 V |
| Output current | 3 A continuous |
| Output voltage | Adjustable down to 0.8 V |
| Reference voltage | 0.8 V (0.772 to 0.828 V) |
| Switch | Integrated 80 mΩ high-side MOSFET |
| Switching frequency | Fixed 570 kHz |
| Shutdown current | 1 µA typical, 4 µA maximum (EN = 0 V, VIN = 12 V) |
| Control | Current mode with internal slope compensation; adjustable slow start; programmable UVLO |
| Protection | Cycle-by-cycle current limit, frequency foldback, overvoltage transient protection, thermal shutdown (165 °C) |
| Junction temperature | −40 to 150 °C |
| Package | SOIC-8 or SO PowerPAD-8 |

The output voltage is set with a divider from the output to the feedback pin; the output follows from the 0.8 V reference. Because the part is not synchronous it needs an external catch diode, an inductor and ceramic capacitors; the datasheet has the design equations.

## Using it on a robot

- Use it for a 12 V or 24 V battery down to 5 V or 3.3 V, where a linear regulator such as the [LM7805](https://roboticsengineering.in/components/lm7805-fixed-regulator/) would waste too much as heat.
- Keep the switching loop (input capacitor, switch, diode) small and on one side of the board, as the datasheet layout section advises.
- Use the PowerPAD package with a copper area under it if you load it near 3 A.
- Check the ripple on the output with a scope before you power a microcontroller or sensor from it.

## Sources and further reading

- [Texas Instruments TPS54331 datasheet (SLVS839H)](https://www.ti.com/lit/ds/symlink/tps54331.pdf) — input range, current, reference, frequency, shutdown current and protection above.

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