Microchip MCP73871 Li-ion battery charge management control program

Microchip MCP73871 Li-ion battery charge management control program

Microchip's MCP73871 is a discrete function of the system load balancing Laptop Battery Li-ion / Li-Polymer battery charge management controller and battery can be input to choose between the power supply: single-cell lithium-ion battery or input power (ac-dc wall adapter or USB port). MCP73871 device constant current / constant voltage (CC / CV) charging method, charge termination point optional. Widely used in GPS / navigation systems, PDA and smart phones, portable media players and MP3 players, digital cameras, Bluetooth headsets and portable medical equipment. This article describes the main features of the MCP73871, function block diagram, typical applications, and MCP73871 Evaluation Board features, circuit diagrams and the use of materials (BOM).

MCP73871: load balancing with the system features discrete lithium-ion / Li-Polymer Battery Charge Management Controller

MCP73871 devices to achieve the system load balancing and the adoption of ac-dc wall adapter or USB port power supply to the lithium-ion / Li-polymer battery dell laptop battery provides a fully integrated linear solution. It can input and battery to choose between the power supply. The device is not only small and requires fewer external components, makes it very suitable for portable applications.

MCP73871 device can automatically choose to provide to the system load power, single-cell lithium-ion battery or input power (ac-dc wall adapter or USB port). MCP73871 devices fully meet the USB specification limits the current consumption. The introduction of ac-dc wall adapter power supply to the system, the external resistor will be the maximum charge current amplitude is set to 1A, to support the system load and battery charge current is 1.8A or less the sum of the occasion. dell 312-0292 battery MCP73871 device constant current / constant voltage (CC / CV) charging method, charge termination point optional.

There are four kinds of options to choose from a fixed constant voltage: 4.10V, 4.20V, 4.35V or 4.40V in order to meet the emerging requirements of battery charging. In the high power or high ambient temperature conditions, MCP73871 device will be under the die temperature to limit the charge current. Adjusted according to the temperature of this feature to shorten the charging time, but also to ensure the reliability of the device.

MCP73871 device with a low battery directives, power voltage of the normal direction and two charge status indicator, the output can be connected with the LED, or communicate with the host microcontroller. MCP73871 device in the environment temperature -40 ° C to +85 ° C within the scope of the indicators completely normal.

MCP73871 Features

Integrated load balancing, and battery charging systems management functions

For the system power supply and to the lithium-ion battery at the same time

Voltage and current proportional control dell Inspiron 2200 battery (Voltage Proportional Current Control, VPCC) to ensure that the priority of the system load is higher than lithium-ion battery charge current

Off through the realization of the ideal diode low loss power path management

The full linear charge management controller

Integrated transistor

Integrates the current detection

Integration of the reverse-discharge protection

Optional input power: USB port or AC-DC wall adapter

The default precision charge voltage:

4.10V, 4.20V, 4.35V or 4.40V

Tolerance ± 0.5% voltage regulator

Can be thermal regulation of the Constant Current / Constant Voltage (Constant Current / Constant Voltage, CC / CV) Operation

Maximum total input current control 1.8A

Programmable fast-charge current dell Inspiron 1000 battery (using resistance control) Range: 50 mA to 1A

Resistor-programmable charge termination set-point

Optional USB input current control

Absolute max: 100 mA (low) / 500 mA (high)

Auto-recharge

Automatic charging end of the control

With enable / disable control, safety timer

To the depth of depleted batteries 0. 1C pre-charge

Battery Temperature Monitor

Undervoltage lockout (Undervoltage Lockout, UVLO)

Low battery instructions (LBO)

Supply voltage and normal directions (PG)

Charge status and fault conditions, the instructions

Temperature Range: -40 ° C to 85 ° C

Package: 20-pin QFN (4 mm × 4 mm)

MCP73871 Application:

GPS / Navigator

PDA and smart phones

Portable media players and MP3 players

Digital Cameras

Bluetooth Headset

Portable Medical Equipment

Block-type charger / docking station

Toys

 

Functional Block Diagram Figure 1.MCP73871

MCP73871 Evaluation Board

In the portable electronic design, space and complexity are two key dell TD347 battery factors to be considered. The highly integrated device includes the development of new MCP73871 Li-Ion / Li-polymer battery-powered products needed for a number of components across the barrier design to meet the design requirements of portable electronics.

MCP73871 device requires only minimal external components will be able to supply the load to the system, respectively, as well as to the single-cell lithium-ion batteries. When they are not applied input power or its power is not enough, the lithium-ion batteries will become the main power supply or to act as auxiliary power supply to provide the required system load current. Development MCP73871 Evaluation Board is designed to help product designers to use the popular Microchip system load balancing capabilities with discrete lithium-ion battery charge management controller to simplify product design, shorten product design time.

MCP73871 Evaluation Board demonstrates Microchip's MCP73871 "with the system load balancing capabilities of discrete linear Li-Ion / Li-Polymer battery dell KD476 battery charge management controller" function.

MCP73871 Evaluation Board is designed to default to the system load and the charging voltage of 4.2V (MCP73871 are 4.1V, 4.35V and 4.4V regulator option), single-cell lithium-ion battery to provide at least the total current of 1.5A.

MCP73871 Evaluation Board has two toggle switch (dip switch) is used to select the input current limit. The first toggle switch (SW2) is used to Ac-Dc adapter and USB port (AC / USB) input power to choose between. The second toggle switch (SW1) is used in the 500 mA high-current USB ports, or 100 mA low current USB ports (high / low) to choose between. When using SW2 selected USB as a power source, the input current limit by the USB specification.

When using SW2 select AC adapter, the maximum fast-charge current from the resistor (RPROG1) is set to 1A, charge termination current from the resistor (RPROG3) is set to 100 mA.

MCP73871 Evaluation Board provides three status LED, 2 as a charge status output, an dell GD761 battery indicator as a normal power supply voltage.

MCP73871 Evaluation Board Kit includes:

MCP73871 Evaluation Board, 102-00183

Analog and Interface Products Demonstration Board CD-ROM (DS21912)

MCP73871 Evaluation Board Users Guide (DS51755)

MCP73871 Data Sheet "Stand-Alone Linear Li-Ion / Li-Poly Battery Charge and

System Load Sharing Management Controller "(DS22090)

MCP73871 Evaluation Board demonstrates the use of Microchip's discrete linear Li-Ion battery dell Inspiron 1501 battery charger to achieve system power path management control and load balancing solution. When the disconnect input power, the lithium-ion batteries to give the system load. MCP73871 offers a large number of device options, so that it can be used in a variety of applications. To learn more about the device options, please see the MCP73871 Data Sheet (DS22090A_CN) and / or contact your local Microchip technical support.

Reference design can be used as a typical application of a smart phone, PDA, portable media players, MP3 players, digital cameras, handheld medical devices, Bluetooth headsets, ultra-mobile PC and portable transmitters.

MCP73871 Evaluation Board has the following features:

Integrated load balancing system

Available toggle switch control input current limit, for Ac-Dc adapter, a typical value of 1650 mA, for USB high-current input, max 500 mA, for USB low-current input, max 100 mA

3 LED to indicate charging status, battery power is low and the supply voltage normal signals

Pre-lithium-ion battery charge voltage: 4.2V ± 0.5%

By default, the temperature monitors have been banned, but can be enabled for the introduction of NTC thermistor for temperature monitoring

Factory default for the depth of dell Inspiron E1505 battery depletion of the pre-charge the battery 0.1C

Factory pre-set with a timer function of time-out period to enable a 6-hour security timer

Constant current / constant voltage (CC / CV) charging method

By a resistor to set the maximum charge current: 1A

The termination charge set by the resistor set-point: 100 mA

Automatic charge termination

Auto-recharge

Internal thermal regulation

With an extra hole at the bottom of the exposed pad to better dell Inspiron 6400 battery heat dissipation too