描述 Description

The MCP73871 device is a fully integrated linear

solution for system load sharing and Li-Ion/Li-Polymer

battery charge management with AC-DC wall adapter

and USB port power sources selection. It is also

capable of autonomous power source selection

between input and battery. Along with its small physical

size, the low number of required external components

makes the device ideally suited for portable

applications.

The MCP73871 device automatically obtains power for

the system load from a single-cell Li-Ion battery or an

input power source (AC-DC wall adapter or USB port).

The MCP73871 device specifically adheres to the

current drawn limits governed by the USB specification.

With an AC-DC wall adapter providing power to the

system, an external resistor sets the magnitude of 1A

maximum charge current while supporting up to 1.8A

total current for system load and battery charge

current.

The MCP73871 device employs a constant

current/constant voltage (CC/CV) charge algorithm

with selectable charge termination point. To

accommodate new and emerging battery charging

requirements, the constant voltage regulation is fixed

with four available options: 4.10V, 4.20V, 4.35V or

4.40V. The MCP73871 device also limits the charge

current based on the die temperature during high

power or high ambient conditions. This thermal

regulation optimizes the charge cycle time while

maintaining device reliability.

The MCP73871 device includes a low battery indicator,

a power good indicator and two charge status

indicators that allow for outputs with LEDs or

communication with host microcontrollers. The

MCP73871 device is fully specified over the ambient

temperature range of -40°C to +85°C.

特性 Features

? Integrated System Load Sharing and Battery

Charge Management

- Simultaneously Power the System and

Charge the Li-Ion Battery

- Voltage Proportional Current Control (VPCC)

ensures system load has priority over Li-Ion

battery charge current

- Low-Loss Power-Path Management with

Ideal Diode Operation

? Complete Linear Charge Management Controller

- Integrated Pass Transistors

- Integrated Current Sense

- Integrated Reverse Discharge Protection

- Selectable Input Power Sources: USB Port or

AC-DC Wall Adapter

? Preset High Accuracy Charge Voltage Options:

- 4.10V, 4.20V, 4.35V or 4.40V

- ±0.5 Regulation Tolerance

? Constant Current/Constant Voltage (CC/CV)

Operation with Thermal Regulation

? Maximum 1.8A Total Input Current Control

? Resistor Programmable Fast Charge Current

Control: 50 mA to 1A

? Resistor Programmable Termination Set Point

? Selectable USB Input Current Control

- Absolute Maximum: 100 mA (L)/500 mA (H)

? Automatic Recharge

? Automatic End-of-Charge Control

? Safety Timer With Timer Enable/Disable Control

? 0.1C Preconditioning for Deeply Depleted Cells

? Battery Cell Temperature Monitor

? Undervoltage Lockout (UVLO)

? Low Battery Status Indicator (LBO)

? Power Good Status Indicator (PG)

? Charge Status and Fault Condition Indicators

? Numerous Selectable Options Available for a

Variety of Applications:

- Refer to Section 1.0 “Electrical

Characteristics” for Selectable Options

- Refer to the Product Identification System

for Standard Options

? Temperature Range: -40°C to +85°C

? Packaging: 20-Lead QFN (4 mm x 4 mm)

Applications

? GPSs/Navigators

? PDAs and Smart Phones

? Portable Media Players and MP3 Players

? Digital Cameras

? Bluetooth? Headsets

? Portable Medical Devices

? Charge Cradles/Docking Stations

? Toys