Buck
LM2596 Buck Converter Module
Adjustable step-down module built on the LM2596 — trimpot-set output, wide input range, heavy vendor variance on everything except the chip itself.
Generic (various OEMs, built around the TI LM2596)
Overview
A DC-DC buck converter breakout: four screw terminals or pin headers (IN+, IN-, OUT+, OUT-) around an LM2596 switching regulator and a small blue trimpot that sets the output voltage by feel, not by spec. The chip inside is a known quantity — TI's LM2596 switches at a fixed 150kHz and is rated for up to 3A output — but almost nothing else about the module is standardized. Sellers use different inductors, different output capacitor ESR, different trace widths on the input/output pads, and the trimpot ships at an unpredictable position out of the bag, so the very first thing to do with a new module is measure its output with a multimeter under no load before connecting anything to it. Treat the 3A rating on the silkscreen as optimistic: sustained current much above 1.5-2A usually needs the module's tiny inductor and (usually absent) heatsinking to not run hot. Good for stepping a 9-24V wall supply or a 2S/3S LiPo pack down to 5V or 3.3V for a board's power input; not a precision reference — expect noticeable output ripple compared to a linear regulator.
Wiring tip: IN+/IN- from the raw supply, OUT+/OUT- to the load — adjust the trimpot and verify with a meter BEFORE connecting a load
Pins & wiring
LM2596 Buck Converter Module
Module
Physical pin order shown left to right.
All pins
Hover · click to selectSelected pin
IN+
- Direction
- Power
Raw, unregulated input — the supply you're stepping down.
Full pin table
| Pin | Name | Role | Direction | Note |
|---|---|---|---|---|
| IN+ | Power | Power | Raw, unregulated input — the supply you're stepping down. | |
| IN- | Ground | Passive | — | |
| OUT+ | Power | Out | Regulated output, set by the trimpot. | |
| OUT- | Ground | Passive | — |
Wiring examples
12V supply stepped down to feed a board's 5V rail directly
Any 5V hostCommon when running several 5V loads (servos, NeoPixels) off a 12V supply and wanting to feed the board's 5V pin directly, bypassing its own onboard regulator's lower current limit.
| LM2596 Buck Converter Module pin | Connects to | Note |
|---|---|---|
| OUT+ | 5V | Feeds the board's 5V rail directly — verify the trimpot is actually set to 5.0V first. |
| OUT- | GND | — |
- Adjust the trimpot and confirm the output voltage with a multimeter, with NOTHING connected to OUT+/OUT-, before wiring it to a board. Modules ship at an arbitrary trimpot position — some have been measured well above 12V out of the box, which will destroy a 5V-only board instantly.
- Feeding a board's 5V pin directly (rather than its barrel jack/VIN) bypasses that board's own onboard protection and regulation — a mistake here goes straight to every 5V part on the board.
- Common ground between the buck module's input side and output side is automatic (it's one board), but if the input supply and the powered board have any OTHER shared ground path, check for ground loops.
Specifications
Electrical
- Topology
- buck
- Min Input Voltage
- Varies by vendor
- Max Input Voltage
- Varies by vendor
- Output Voltage
- N/A
- Adjustable Output
- Yes
- Max Output Current
- Varies by vendor
- Dropout Voltage
- N/A
- Quiescent Current
- Varies by vendor
Performance
- Peak Efficiency
- Varies by vendor
- Switching Frequency
- 150 kHzsrc
Physical
- Package
- Module
- Length
- Varies by vendor
- Mounting
- module
Footprint
No independently verified physical footprint is on file for this part yet.
Alternatives
Budget options
Cheaper, with a stated tradeoff — read the reason before swapping.
Load only needs a few hundred mA at a fixed 3.3V and the input is already close to 5V — a linear regulator is simpler, cheaper, and has no switching noise, at the cost of wasting the voltage difference as heat.
Compare with LM2596 Buck Converter Module- Topology: switching (buck) → linear (LDO) — Only sensible when Vin isn't much above Vout — the AMS1117 can't step down 12V to 3.3V without cooking itself.
Similar parts
Does the same job with a different part. Expect wiring and library changes — a starting point, not a guarantee.
Fixed 5V output instead of adjustable, same 'linear regulator' simplicity tradeoff — no trimpot to accidentally leave mis-set, but far worse efficiency at high input voltages.
Compare with LM2596 Buck Converter Module- Adjustable output: true → false
Documents
Datasheets
- LM2596 SIMPLE SWITCHER Power ConverterTexas Instruments
Frequently asked questions
What voltage does the LM2596 Buck Converter Module run at?
Banana Board does not have a verified operating voltage on file for the LM2596 Buck Converter Module yet — check the datasheet in Documents before wiring it up.
How many pins does the LM2596 Buck Converter Module have?
The LM2596 Buck Converter Module has 4 pins. See the full pinout table in Pins & wiring for each pin's role.
Can I simulate the LM2596 Buck Converter Module before ordering hardware?
Not yet — the LM2596 Buck Converter Module does not have a live simulation model in Banana Board today, so validate the wiring here and test on real hardware.
Where is the LM2596 Buck Converter Module datasheet?
Linked in the Documents section on this page, and cited on every spec that came from it.
Related references
Build it, do not just look it up
Describe your circuit in one sentence and Banana Board wires it to these exact pins, validates it, and lays out a fab-ready PCB.