LM2596 Buck Converter Module
Adjustable buck converter for efficiently stepping down higher voltages to project logic levels.
An adjustable buck (step-down) converter module used to efficiently drop higher battery voltages down to a project's logic-level supply. Built around the LM2596 switching regulator IC, it converts a higher input voltage down to a lower, adjustable output set by an onboard trimmer potentiometer, with far less wasted heat than a linear regulator — the standard choice for powering 5V or 3.3V electronics from a 9V, 12V, or higher battery/adapter source in DIY projects.
Specifications
| Converter type | LM2596 adjustable DC-DC buck (step-down) converter |
| Input voltage | 4.5V–40V DC (practical range; must exceed the desired output plus ~1.5V dropout) |
| Output voltage | Adjustable from ~1.25V to ~35V DC via onboard trimmer potentiometer |
| Output current | Up to ~3A typical (with adequate heatsinking/cooling at higher loads) |
| Switching frequency | ~150 kHz |
| Efficiency | Up to ~92% typical, much cooler-running than a linear regulator dropping the same voltage difference |
| Adjustment | Onboard trimmer potentiometer sets output voltage — measure with a multimeter under no/light load while adjusting |
Pinout
| Pin | Name | Description |
|---|---|---|
| 1 | IN+ | Positive voltage input from battery/power source |
| 2 | IN- | Negative input / ground |
| 3 | OUT+ | Positive regulated stepped-down output |
| 4 | OUT- | Negative output / ground (shared with IN-) |
As with other adjustable regulator boards, set the output voltage using the onboard trimmer potentiometer and a multimeter before connecting sensitive electronics — these modules ship at an arbitrary factory-set voltage. Input voltage must be at least ~1.5V higher than the desired output for the regulator to maintain regulation; if the input voltage is already lower than what you need, use a boost converter like the MT3608 instead, since buck converters cannot step voltage up.
Variants
Reach for the LM2596 whenever you need to drop a higher voltage source down to a lower project voltage efficiently. If your input voltage is already lower than the target output, you actually need a boost converter like the MT3608 instead — buck and boost converters solve opposite problems and aren't interchangeable.
| Variant | Temp range | Hum range | Accuracy | Protocol | Price |
|---|---|---|---|---|---|
| LM2596 buck module | ~$1-3 | ||||
| MT3608 (boost/step-up) | ~$1-3 | ||||
| Fixed-output buck module (e.g. 5V-only) | ~$1-2 |