Pololu 12V Step-Up/Step-Down Voltage Regulator S18V20F12

The S18V20F12 is a compact 12V step-up/step-down (buck-boost) regulator that keeps your output at 12V even when your input voltage moves above or below it. It uses a SEPIC switching topology (high efficiency, lower heat vs linear regulation), making it ideal for battery-powered builds where voltage drops as the pack discharges—yet you still need a stable 12V rail for your system.

Wide input range: accepts roughly 2.9V to 32V (treat 32V as absolute max; 30V recommended due to reverse-voltage protection limit).
Stable 12V output: fixed output with 4% accuracy.
Powerful when VIN is near 12V: typical max output current is about 2A when input voltage is close to the output (actual continuous current depends on thermal dissipation).
Efficient conversion: typical efficiency is 80% to 90% depending on VIN, VOUT and load.
Built-in protections: reverse-voltage protection (up to 30V), over-current protection, thermal shutdown (typically ~165°C), and under-voltage lockout (turns off around 2.5V typical).

Important notes (quick buyer FAQ killers):

“2A” is not guaranteed at all VIN: max usable current depends on VIN vs 12V, efficiency, airflow, and ambient temperature (boosting from low VIN reduces available output current).
ENABLE doesn’t fully disconnect output: due to the SEPIC topology, there’s an inherent capacitor path from input to output, so VOUT is not completely isolated when disabled.
It can get hot: during normal operation this board can become hot enough to burn—mount with airflow/clearance.

Why/Benefits

Perfect for batteries that sag

Maintains 12V even when a battery starts above 12V and later drops below it
Lets you use more battery pack options (cell counts/form factors) while keeping the same 12V load
Typical quiescent current is ~1mA in many VIN/VOUT combinations; use ENABLE sleep for low idle draw

Project-friendly hardware

Compact board with multiple wiring options: terminal blocks, 0.1" headers, or direct solder
4 mounting holes sized for #2 / M2 screws (also useful for strain relief)
Reverse-voltage + thermal protection helps protect your build

Technical specifications

Product	Pololu 12V Step-Up/Step-Down Voltage Regulator S18V20F12
Topology	SEPIC switching regulator (step-up/step-down)
Input voltage	2.9V to 32V (32V absolute max; 30V recommended)
Output voltage	12V fixed (±4% accuracy)
Typical max output current	~2A when VIN is close to VOUT (continuous current depends on thermals)
Typical efficiency	80% to 90% (varies with VIN, VOUT, load)
Quiescent current	~1mA typical (can rise significantly in extreme boost conditions); sleep via ENABLE reduces to ~10–20µA per volt on VIN
Protections	Reverse-voltage protection (to 30V), over-current protection, thermal shutdown (~165°C typical), under-voltage lockout (~2.5V typical)
Size	1.7" × 0.825" × 0.38" (43 × 21 × 10mm)
Mounting	4× 0.086" holes for #2 or M2 screws

Pinout & power notes

VIN: input supply (keep within range; 30V recommended).
GND: common ground.
VOUT: regulated 12V output.
ENABLE: pulled up by default (board ON). Drive low (<0.7V) for low-power sleep; leave floating if you don’t need the feature.
Wiring options: use the included 2-pin 5mm terminal blocks in the larger holes, or solder 0.1" headers into the small holes for breadboards/0.1" systems.

FAQ

When should I use a step-up/step-down regulator instead of a buck converter?

Use step-up/step-down when your input might be above or below 12V (common in battery packs as they discharge). If VIN is always above 12V, a buck converter can be simpler; if VIN is always below 12V, a boost converter is often better.
Can it really do 2A?

2A is a typical maximum when VIN is close to 12V. At low VIN (boosting), available output current drops and thermal limits apply—design with airflow and margin.
Does ENABLE fully cut power to the output?

Not completely—SEPIC regulators have an inherent capacitor path from input to output, so VOUT is not fully isolated even when disabled.

Pololu 12V Step-Up/Step-Down Voltage Regulator S18V20F12

Name: Pololu 12V Step-Up/Step-Down Voltage Regulator S18V20F12
Brand: circuitrocks
SKU: POL2577
Price: 2238.0 PHP
Availability: InStock