Step-Down converter D36V50F9 with an output voltage of 9 V, an input voltage from 9.9 to 50 V and a maximum output current of 7 A. Pololu 4094

Step-Up converter U3V70A with an output voltage from 4.5 to 20 V, an input voltage from 2.9 to VOUT and a maximum output current of 10 A. Pololu 2890

The compact (0.4″ × 0.5″) D24V5F9 synchronous buck voltage regulator takes an input voltage of up to 36 V and efficiently reduces it to 9 V while allowing for a maximum output current of 500 mA. Pololu 2845

Step-Down DC-DC converter module based on the D24V150F7 chip. Input voltage 9..40V, output voltage 7.5V (max 15A). Pololu 2883

KAmod TPS5401 is a compact Step-Down switching regulator based on the energy-efficient TPS5401 chip, providing an output voltage of 3.3 V, 5 V, or 12 V (depending on the version). It supports a maximum continuous current of 0.5 A and a wide input voltage range of 4...42 V, while its 2.54 mm pitch terminals allow for easy mounting.

The compact (0.4″ × 0.5″) D24V5F2 synchronous buck voltage regulator takes input voltages between 3 V and 36 V and efficiently reduces them to 2.5 V while allowing for a maximum output current of 500 mA. This regulator offers typical efficiencies between 80% and 90%. The pins have a 0.1″ spacing, making this board compatible with standard solderless breadboards and perfboards.

The very small step-down 6 V, 2.5 A synchronous inverter can be supplied with voltage up to 36 V, dimensions: 17.8 mm x 17.8 mm. Pololu 2859

This small synchronous switching step-down (or buck) regulator takes an input voltage of up to 36 V and efficiently reduces it to 7.5 V. The board measures only 0.7″ × 0.7″ yet delivers a typical continuous output current of up to 2.4 A and features reverse voltage protection.

The MyoWare Power Shield is designed to take two standard CR2032 coin cell batteries to power the MyoWare Muscle Sensor. We have made this board in a way that the coin cell batteries are connected in parallel for extended capacity at a nominal 3.0V. DEV-13684

A high-efficiency UBEC switching regulator for powering receivers and servos in RC models with 2–8 S LiPo batteries. It provides a stable voltage of 5.25 V with a load of up to 5 A, with power reserve for temporary overloads, ideal for large models requiring a reliable power source.

This synchronous switching step-down (or buck) regulator takes an input voltage of up to 40V and efficiently reduces it to 5V with an available output current of around 15A. Typical efficiencies of 80% to 95% along with its high current capabilities make this regulator well suited for powering large loads. Pololu 2881

Step-Up converter U3V70F7 with an output voltage of 7.5V, an input voltage from 2.9 to 7.5 V and a maximum output current of 10 A. Pololu 2893

This synchronous switching step-down (or buck) regulator takes an input voltage of up to 40 V and efficiently reduces it to 3.3 V with an available output current of around 15 A. Pololu 2880

This synchronous switching step-down (or buck) regulator takes an input voltage of up to 40 V and efficiently reduces it to 6 V with an available output current of around 15 A. Pololu 2882

The S9V11MA switching step-up/step-down regulator efficiently produces a finely adjustable output between 2.5 V and 9 V whether it is higher or lower than the input voltage, which can range from 2 V to 16 V.  Pololu 2869 

The S9V11F3S5CMA switching step-up/step-down regulator efficiently produces a fixed 3.3 V (default) or 5 V (selectable) output whether it is higher or lower than the input voltage, which can range from 2 V to 16 V. (Note: minimum start-up voltage is 3 V, but it operates to 2 V after that.)

The Step-Up Buck Voltage Regulator module with output voltage of 3.3V and input voltage range of 1-3V and a maximum output current of 200 mA. STMicroelectronics EVAL4971

Step-Up converter U3V70F15 with an output voltage of 15 V, an input voltage from 2.9 to 15 V and a maximum output current of 10 A. Pololu 2896