I2C to Dual UART Module - I2C - 2x UART converter

An efficient step-down converter that steps down the input voltage from as low as 45 V to a regulated output voltage range of 1.4 to 7 V, offering high efficiency and a maximum continuous current of 3.8 A. It has built-in reverse polarity, overload and short circuit protection, and the spread spectrum function reduces EMI interference. Pololu 4853

AP3429A DC-DC Step-Down Converter Module with 1.8 V output voltage, 2.7 to 5.5 V input voltage and 2 A maximum output current. SparkFun COM-21338

The Step-Down Converter Module converts 4-40V to a regulated output voltage of 1.25-36V, supporting a maximum of 8A and 200W, with a conversion efficiency of 94%. It is a compact device (61 x 41 x 27 mm) using PWM modulation, ideal for industrial applications requiring a stable output voltage.

DC-DC Step-Down converter module with 5V output voltage and 1A output current. The module can be a replacement for the popular LM7805 regulator.

A compact voltage converter module that reduces input voltage from 9.4 to 65 V to a stable 9 V at up to 700 mA. It features high efficiency, low quiescent current (<0.2 mA), and short-circuit and thermal protection, ensuring safe and efficient operation. Its small size and ease of integration make it ideal for mobile devices, battery-powered designs, and systems requiring stable power. Pololu 5436

The Step-Down Converter Module with Voltmeter and Ammeter offers a wide input and output voltage range, with a maximum output current of 12A and a power of 160W. It comes with advanced monitoring and protection features and its conversion efficiency is around 96%.

The Step-UpU1V11A Buck Voltage Regulator module with adjustable output voltage 2-5.25V, input voltage range of 0.5-5.5V and a maximum output current of 1.2A. Pololu 2560

The Step-Down D24V6F3 Buck Voltage Regulator module gives the output voltage of 3.3V with a wide input voltage range of 4.8-42V and a maximum output current of 600 mA. Pololu 2106

Step-Down converter with adjustable or constant output voltage from 0.8 to 17 V, input voltage from 4.5 to 24 V and a maximum current of up to 3 A

This synchronous switching step-down (or buck) regulator takes an input voltage of up to 38 V and efficiently reduces it to 5 V with an available output current of around 9 A.

This small synchronous switching step-down (or buck) regulator takes an input voltage of up to 36V and efficiently reduces it to 5V. The board measures only 0.7″ × 0.7″ yet delivers a typical continuous output current of up to 2.5A and features reverse voltage protection. Pololu 2858

DC-DC Step-Up/Step-Down Converter Module. It has an input voltage of 1.4 to 16 V, an output voltage of 6 V and a maximum output current of 1 A to 1.5 A. Pololu 4966

Power switch that enables efficient power management of devices in the Qwiic ecosystem, allowing selective shutdown of devices and energy saving. The module offers I2C bus isolation, additional GPIO pins and works with SparkFun Qwiic Mux, making it easy to control multiple devices in your projects. SparkFun PRT-26784

The Step-Up / Step-Down S18V20F12 inverter module gives the output voltage of 12V with a wide input voltage range of 3 ... 30V and a maximum output current of 2A. Polol 2577

DC-DC Step-Down converter module AP63203 with an output voltage of 3.3 V, an input voltage of 3.8 to 32 V and a maximum output current of 2 A. SparkFun COM-18356