LiFePO4 charger with programmable current and timer
The MCP73123-22SI/MF is a single-cell Lithium Iron Phosphate (LiFePO4) battery charge management controller in a 10-DFN (3x3 mm) package. It targets portable and backup-power designs where a 3.6 V battery pack voltage and a programmable charge current up to 1.1 A are needed.
The 1.1 A maximum charge current is programmable via an external resistor or current-source setting, not a fixed output — the constant-current phase is adjustable down to lower rates.
Package and board-fit notes
The 10-VFDFN Exposed Pad package (3x3 mm DFN) has a large thermal pad on the underside — the board layout must include a thermal via array under the pad to pull heat away from the die during constant-current charging at 1.1 A. The exposed pad is also the ground return; a solid connection to the PCB ground plane is required for both thermal and electrical performance. Surface-mount assembly with a 0.50 mm pitch DFN — the pad geometry matches the standard JEDEC MO-229 footprint.