If you're into DIY electronics, you know how important power efficiency is, especially for battery-powered projects. Today, we’ll build a simple but effective ultra-low power boost converter using the TLV61220DBVR. This tiny yet powerful boost converter allows us to step up low voltages (as low as 0.7V) to a usable level, making it ideal for running small microcontrollers, sensors, or other low-power electronics from a single AA or AAA battery.

Why Use the TLV61220DBVR?

The TLV61220DBVR is a high-efficiency boost converter designed for ultra-low power applications. Some of its key benefits include:

● Operates at ultra-low input voltages (0.7V - 5.5V) – perfect for single-cell battery applications.

● High efficiency (up to 95%) – minimizes power loss and extends battery life.

● Compact size (SOT-23-5 package) – ideal for space-constrained designs.

● Low quiescent current (~5µA) – ensures minimal power drain when idle.

This makes it an excellent choice for battery-operated IoT devices, wearables, and low-power sensors.

Project Overview: Battery-Powered Sensor Node

For this DIY project, we'll build a battery-powered sensor node that can power a small environmental sensor (such as a temperature or humidity sensor) using just a single AA battery. The TLV61220DBVR will step up the battery voltage (which can drop as low as 0.9V) to a stable 3.3V, allowing the sensor to operate reliably.

Materials Required

● TLV61220DBVR Boost Converter IC

● Inductor (4.7µH - 10µH)

● Schottky Diode (e.g., BAT54 or SS14)

● Capacitors (1µF and 10µF, ceramic)

● Resistors (as needed for load regulation)

● AA or AAA Battery Holder

● Environmental Sensor (e.g., DHT11, BMP280)

● PCB or Prototype Board

● Wires and Soldering Tools

Step 1: Understanding the Circuit

The goal is to step up the 1.2V-1.5V output from the AA battery to a regulated 3.3V to power our sensor. The TLV61220DBVR will handle this conversion with minimal power loss.

Main Functional Blocks

1. Power Source: A single AA or AAA battery.

2. Boost Converter Circuit: The TLV61220DBVR, along with an inductor, diode, and capacitors, to generate a stable 3.3V output.

3. Load (Sensor Node): A temperature/humidity sensor that operates at 3.3V.

Step 2: Assembling the Circuit

1. Connecting the TLV61220DBVR

● Identify the VIN, VOUT, GND, L (Inductor), and FB (Feedback) pins on the TLV61220DBVR.

● VIN (Input Voltage): Connect to the positive terminal of the AA battery.

● GND (Ground): Connect to the battery's negative terminal.

2. Inductor Selection and Placement

· Choose a 4.7µH to 10µH inductor. This helps the TLV61220 store energy and efficiently boost voltage.

● Solder one end of the inductor to the L pin and the other end to VOUT.

3. Schottky Diode Connection

● Connect the anode (positive side) of the Schottky diode to the inductor's output.

● Connect the cathode (negative side) to the VOUT pin.

4. Capacitors for Stability

● Place a 1µF capacitor between VIN and GND (input side).

● Place a 10µF capacitor between VOUT and GND (output side).

● These capacitors help smooth out voltage fluctuations.

5. Setting the Output Voltage

● The TLV61220DBVR has a Feedback (FB) pin, which helps regulate the output voltage.

● Use an appropriate resistor divider network to set the output to 3.3V.

● A typical setup uses a 470kΩ resistor (high-side) and a 150kΩ resistor (low-side) to achieve 3.3V.

Step 3: Connecting the Sensor

● Most environmental sensors operate at 3.3V, so connect:

—  VCC of the sensor to VOUT of the boost converter.

—  GND of the sensor to GND of the circuit.

—  Data output of the sensor to a microcontroller (optional).

Step 4: Testing and Optimization

1. Power On the Circuit

● Insert an AA battery into the holder.

● Measure the output voltage using a multimeter—it should be 3.3V.

2. Check Efficiency

● If the output voltage is unstable, try adjusting the inductor value or capacitor sizes.

● Ensure that the Schottky diode is fast-switching and has low forward voltage drop.

3. Connect the Sensor

● If using a microcontroller (e.g., an ESP8266 or Arduino), ensure it correctly reads data from the sensor.

● Verify that the sensor operates reliably under different battery conditions.

Step 5: Improving Battery Life

To make this project energy-efficient, consider these power-saving tips:

● Use a low-power microcontroller (e.g., ATtiny85 or ESP32 in deep-sleep mode).

● Reduce the sensor sampling rate (e.g., take readings every minute instead of continuously).

● Use a larger inductor (e.g., 10µH instead of 4.7µH) to improve efficiency.

● Use high-quality capacitors with low ESR to reduce energy loss.

Step 6: Finalizing the Project

● Solder the components onto a small prototype board or custom PCB.

● Enclose the circuit in a small casing for protection.

● Label connections for easier troubleshooting.

Applications of This Project

This low-power boost converter can be adapted for various applications, such as:

● Wearable health monitors powered by a coin cell or single battery.

● Remote weather stations using energy-efficient sensors.

● IoT devices that require stable power from low-voltage sources.

● Solar-powered gadgets with small rechargeable cells.

Conclusion

By using the TLV61220DBVR, we successfully built an ultra-low power boost converter that efficiently steps up a single AA battery's voltage to power a sensor node. This project demonstrates how simple components can significantly improve energy efficiency, making it ideal for long-lasting battery-powered electronics.

Try modifying this project for your needs—maybe adding solar charging or integrating it into an IoT system. The possibilities are endless!