What is it?

Introducing our compact and ultra-low-power Buck-Boost Converter Module, designed using the high-performance RP605K333B DC/DC converter IC. This versatile module is perfect for powering a wide range of electronic devices, providing a stable 3.3V output (up to 300mA) from varying input sources ranging from 1.8V to 5.5V. This nifty little IC also features built-in Battery Monitor (BM) circuitry that, when enabled, divides the input voltage (VIN/3) and directly provides a buffered voltage to be measured by the ADC. These readings can be used to estimate the state of a battery.

Whether you're working on a DIY project with ESP32/ESP8266 or LoRa/LoRaWAN, developing new Bluetooth/Thread based IoT/Wearable gadgets, or integrating into existing systems, this RP605K333B Buck-Boost Converter Module ensures reliable performance and it's ideal for battery-operated devices (Coin Cell, 2-3S Alkaline, Lithium Ion/Polymer, etc.).

Some specs:

• Input voltage range (VIN): 1.8 V to 5.5 V
• Output current: up to 300 mA
• Output Voltage: 3.3V
• Output Voltage Accuracy: ±1.5%
• Operating quiescent current: ~300 nA
• Shutdown current: 0.01 μA
• Output DC/DC auto-discharge is included
• Efficiency: ~90% in buck mode, ~75% in boost mode
• Battery monitor: VIN/3 typ. 0.1 μA extra supply current
• Operating Temperature: −40 to 85 °C
• Module dimensions: 19.3 mm x 34.5 mm (0.76 in. x 1.36 in.) with 4x M2 mounting holes

Why did you make it?

While designing the Generic Node (SE) I was looking for an ultra-low-power buck-boost converter and after searching for available options this chip captured my attention mainly because of such low quiescent current consumption and the built-in battery monitor circuitry. This enabled us to save some BOM cost and space on our designs.

What makes it special?

This DC/DC converter IC offers some unique features such as Variable Frequency Modulation (VFM) and built-in battery monitoring circuit with only 100 nA supply current. The module is breadboard friendly and all of the pins are broken out for easy interfacing. Additionally, there are two JST-PH connectors on input and output for easy battery and device connections.