User manual

MCP73X23 LITHIUM IRON PHOSPHATE

BATTERY CHARGER EVALUATION

BOARD USER’S GUIDE

Chapter 2. Installation and Operation

2.1 INTRODUCTION

The MCP73123/223 is a highly integrated Li-Ion battery charge management controller

for use in space-limited and cost-sensitive applications. The MCP73123/223 provides

specific charge algorithms for Lithium Iron Phosphate batteries to achieve optimal

capacity and safety in the shortest charging time possible. Along with its small physical

size, the low number of external components makes the MCP73123/223 ideally

suitable for low-cost and small-capacity (less than 2000 mAh) LiFePO

battery

applications. It will take longer time to complete a charge cycle for larger capacity

LiFePO

battery packs.

The absolute maximum voltage, up to 18V over voltage protection, allows the use of

MCP73123/223 in harsh environments, such as low cost ac-dc adapter.

The MCP73123/223 employs a constant current / constant voltage (CC-CV) charge

algorithm and 3.6V per cell voltage regulations. The fast charge, constant current value

is set with one external resistor from 130 mA to 1100 mA. The MCP73123/223 also

limits the charge current based on die temperature during high power or high ambient

conditions. This thermal regulation optimizes the charge cycle time while maintaining

device reliability.

The PROG pin of the MCP73123/223 also serves as enable pin. When high impedance

(typ. 200 kΩ) is applied, the MCP73123/223 will be in standby mode.

Typical applications for the reference design are Toys, Power Tools, Uninterrupt Power

Supply, Backup Power Storage and applications in wider temperature range than

typical Li-Ion batteries.

2.2 FEATURES

The MCP73X23 Lithium Iron Phosphate Battery Charger Evaluation Board has the

following features:

• Input Over Voltage Protection:

- 6.5V for the MCP73123,

- 13V for the MCP73223

• Charge Regulation Voltage:

- 3.6V for the MCP73123,

- 7.2V for the MCP73223

• 10% Preconditioning of Deeply Depleted Cells

• 32-Minute Preconditioning Timer

• 6-Hour Safety Timer

• 10% Automatic Charge Termination

• 500 mA and 1000 mA Preset Fast Charge Current

• Automatic Recharge

• Thermal Regulation

• One Blue LED Charge Status Indicator For Each Circuit

• Pre-installed MCP73123 and MCP73223 Devices