Power Pins

  • VBUS - The 5V power rail from the USB connector
  • OUT - Regulated load output. This pin will provide a regulated output when the input voltage is below the over voltage protection threshold and above the regulation voltage. It will never be higher than 4.4V (but it may dip down to 3V or whatever the LiPo battery voltage is at, if USB/DC isnt plugged in)
  • LIPO - Battery input. Connect to the positive terminal of the battery,
  • GND - Common ground for all power and logic

JST Connectors

The top Load Out connector is the same as the OUT pin - it will have between ~3V and 4.4V output, and can be used to power the load project

The bottom Lipo Batt connector is the same as the LIPO pin - it is the port for connecting the 3.7V/4.2V nominal LiPoly or LiIon battery

Control Pins

  • CE - Charge Enable (active low) - Set or pull to a high logic level to disable charging. This pin is pulled low by a 10K resistor by default.
  • THERM - Optional external NTC Thermistor Input. To use, carefully cut the THERM jumper connection and connect a 10kΩ NTC thermistor in the battery pack to the THERM pin. The thermistor should also be connected to the negative lead of the battery pack (e.g. to ground)
  • ISET - Optional Fast charge current setting input to manually set the charge current if not using the charge current jumpers. Carefully cut the trace on the 1.0A solder jumper and connect a 590-Ω to 8.9-kΩ resistor from ISET to GND to program the fast charge current level. Charging is disabled if ISET is left unconnected. 
    If you just want 0.5A, 1A or 1.5A charge rates, you can use the selectable jumpers in the middle of the board. Cut the 1.0A one and solder closed your desired charge rate!

Status Pins

  • PGOOD - Power Good Status (active low). PGOOD pulls to GND (open drain) lighting the connected led when a valid input source is connected. If the input power source is not within specified limits, PGOOD is disconnected from ground (high impedance) and the LED will be off.
  • CHG - Charge status (active low) pulls to GND (open drain) lighting the connected led when the battery is charging. If the battery is charged or the charger is disabled, CHG is disconnected from ground (high impedance) and the LED will be off.

Solder Jumpers

  • 0.5, 1.0, 1.5A - Used to configure the charge current by connecting ISET to included resistors. To change the charge current, carefully cut the trace on the 1.0A solder jumper and bridge either of the other two current level jumpers.
  • THERM - Connects the thermistor input to ground when not in use. To use a thermistor, carefully cut the THERM jumper connection and connect a 10kΩ NTC thermistor in the battery pack to the THERM pin. The thermistor should also be connected to the negative lead of the battery pack.
  • D+/D- These are the USB data lines from the USB socket. You can attach them along with VBUS and GND to connect the USB socket to something else.
  • EN1 and EN2 - Input current limit configuration. To modify from the default, cut the traces in the jumpers and solder according to the options below

EN1 Low, EN2 Low - 100 mA input current limit

EN1 High, EN2 Low - 500 mA input current limit 

EN1 Low, EN2 High - (Default) Input Current limit set by an 1K external resistor from ILIM to GND

EN1 High, EN2 High - Standby (USB suspend mode)

This guide was first published on Sep 16, 2020. It was last updated on Mar 27, 2024.

This page (Pinouts) was last updated on Mar 27, 2024.

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