Pololu 12V, 2.4A Step-Down Voltage Regulator D36V28F12

Need a dependable 12V rail from a higher-voltage source? The Pololu D36V28F12 is a compact, efficient buck (step-down) switching regulator that converts up to 50V input down to a stable 12V output. It’s a great choice for 24V/36V/48V systems powering 12V loads—especially when you want less heat and better efficiency than linear regulators.

Input range: 12.9V to 50V (minimum depends on dropout vs load).
Output: 12V with 4% accuracy.
Current capability: listed typical max output current is 2.4A at 36V in; continuous current depends on VIN and thermal dissipation.

Why/Benefits

Efficient 12V from high-voltage rails

Typical efficiency 90–95% (VIN/load dependent).
Switching frequency ~500kHz under heavy loads.
Power-save mode keeps operation ultrasonic (>20kHz) while improving light-load efficiency.

Safer + easier to integrate

Enable (EN) input for shutdown/low-power mode (great for battery and remote power control).
Power Good (PG) open-drain indicator when output is out of regulation.
Protections: reverse-voltage (up to 40V), over-current, short-circuit, UV/OV output protection, thermal shutdown, soft-start.

Technical specifications

Pololu item	D36V28F12 Step-Down Regulator
Topology	Buck (step-down) switching regulator
Input voltage (VIN)	12.9V to 50V (minimum depends on dropout vs load)
Output voltage (VOUT)	12V (±4% accuracy)
Typical max output current	2.4A (at 36V in; continuous depends on thermals)
Typical max continuous current range	~2.0A to 3.3A (VIN/thermal dependent; see Pololu graph)
Efficiency	Typically 90% to 95% (VIN/load dependent)
Switching frequency	~500kHz under heavy loads
No-load quiescent current	~1mA to 3mA typical
Size	0.7" × 0.8" × 0.345" (17.8 × 20.3 × 8.8mm)
Mounting	Two 0.086" mounting holes for #2 or M2 screws
Key protections	Reverse-voltage (up to 40V), UV/OV output protection, over-current, short-circuit, thermal shutdown, soft-start

Pinout & power notes

Connections: VIN, VOUT, two GND pins, EN (enable), and PG (power good).
Enable thresholds: pull EN below 1.2V to enter low-power sleep; raise past 1.35V to wake. Sleep draw is ~10–20µA per volt on VIN (dominated by internal pull-up and reverse-protection circuitry).
Power Good (PG): open-drain output goes low when VOUT is >20% high or >10% low (with hysteresis). Requires an external pull-up resistor.
Dropout behavior: practical minimum VIN is approximately VOUT + dropout, and dropout rises with load (see Pololu dropout graphs).
Handling: under load, the board can get hot enough to burn—mount with airflow/clearance.

FAQ

What’s the “real” max current?

The listed typical max is 2.4A at 36V in, but continuous current depends heavily on input voltage, airflow, ambient temperature, and heatsinking. Pololu provides a maximum continuous output current graph for guidance.
Can I use EN for low-battery cutoff?

Yes. Because EN has tight thresholds, you can set a precise low-VIN cutoff using an external voltage divider from VIN.
Do I need a pull-up for PG?

Yes—PG is open-drain. Add a pull-up resistor to your logic voltage to read it.