Preliminary

Datasheet

LP4062

LP4062 –00

Ver. 1.0 Datasheet

Nov.-2007

Page 2 of 13

Functional Pin Description

Pin Number

Pin Name

Pin Function

1

CHRG

Open-Drain Status Output

2

GND

Ground.

3

BAT

Charge Current Output

4

VCC

Positive Input Supply Voltage

5

PROG

Charge Current Program, Charge Current Monitor and Shutdown Pin.

CHRG (PIN 1):

Open-Drain Charge Status Output. When the battery is charging, the CHRG pin is pulled low by an internal

N-channel MOSFET. When the charge cycle is completed, a weak pull-down of approximately 12µA is connected

to the CHRG pin, indicating a “AC present” condition. When the LP4062 detects an undervoltage lockout condition,

CHRG is forced high impedance.

GND (PIN 2): Ground.

BAT (PIN 3): Charge Current Output. Provides charge current to the battery and regulates the final

float voltage to 4.2V. An internal precision resistor divider from this pin sets the float voltage which is

disconnected in shutdown mode.

LP4062 enters shutdown mode, dropping IBAT to less than 2µA.

PROG (PIN 5): Charge Current Program, Charge Current Monitor and Shutdown Pin. The charge

constant-current mode, this pin servos to 1V. In all modes, the voltage on this pin can be used to

measure the charge current using the following formula:

The PROG pin can also be used to shutdown the charger. Disconnecting the program resistor from

ground allows a 3µA current to pull the PROG pin high. When it reaches the 1.94V shutdown

threshold voltage, the charger enters shutdown mode, charging stops and the input supply current

drops to 25µA. This pin is also clamped to approximately 2.4V. Driving this pin to voltages beyond

charger to normal operation.

LP4062