This module is a single-cell Li-ion battery charger based on the Microchip MCP73831. It takes a DC input at VIN, regulates charge current via a programming resistor, provides status indication with an LED, and outputs to the battery at VBAT. Key functions and components:
- Input power connector: VIN
- Charger IC: IC1
- Charge-current programming resistor: Rprog
- Sets charge current (up to 500 mA) according to the MCP73831 datasheet formula
- Decoupling capacitors:
- C1 (80 nF–1 µF on VIN)
- C2 (input decoupling)
- C3 (output decoupling on VBAT)
- Charge-status indicator LED: STAT
- Battery output connector: VBAT
- Common reference (0 V): GND
Workflow: apply a DC source (e.g., 5 V) to [VIN], the MCP73831 regulates and limits charge current according to [Rprog], decoupling capacitors stabilize the rails, and [STAT] indicates charge status (on/fast-charge vs. off/charge-done). The battery attaches at [VBAT].