A COMPACT BUCK CONVERTER Suitable For Wearables And IoT

A buck converter is a DC-DC power device that efficiently steps down a voltage to a lower level. It uses an inductor, resistors, and a capacitor to regulate the output, making it particularly suitable for wearable electronics and IoT devices.

- ASHWINI KUMAR SINHA

Low-dropout regulators (LDOs) offer a more straightforward approach to voltage regulation, but they often dissipate significant energy as heat, thereby undermining efficiency in compact, power-sensitive systems. Buck converters provide a more efficient solution, although the inclusion of an inductor increases the design footprint.

This compact converter design is based on a buck converter IC. The complete power system, including the converter, fits within a 9mm footprint—ideal for space-constrained applications while leaving room for other essential components.

A key feature is its ability to deliver variable output voltages ranging from 1.2V to 3.3V DC, achieved by replacing a fixed resistor with a potentiometer. This enables fine-tuned voltage adjustment to match the specific needs of each device.

The converter may be used as a standalone variable-voltage module or integrated directly into wearable electronics.

The converter is embedded within the device's PCB, providing the desired output voltage range with over 93% efficiency and no thermal issues. The design incorporates the PAM2305D SMD IC, housed in a compact DFN-6 (2 × 2mm) package. Fig. 1 shows the author's DC-DC buck converter integrated into the custom-designed PCB.