Datasheet

MCP73827
DS21704B-page 8 © 2007 Microchip Technology Inc.
3.0 PIN DESCRIPTION
The descriptions of the pins are listed in Table 3-1.
TABLE 3-1: Pin Function Table.
3.1 Logic Shutdown (SHDN)
Input to force charge termination, initiate charge, or ini-
tiate recharge.
3.2 Battery Management 0V Reference
(GND)
Connect to negative terminal of battery.
3.3 Charge Status Output (MODE)
Open-drain drive for connection to an LED for charge
status indication. Alternatively, a pull-up resistor can be
applied for interfacing to a microcontroller. A low
impedance state indicates foldback current limit or con-
trolled current phase. A high impedance indicates con-
stant voltage phase or battery cell disconnected.
3.4 Charge Current Monitor (IMON)
Amplified output of the voltage difference between V
IN
and V
SNS
. A host microcontroller can monitor this out-
put with an A/D converter.
3.5 Cell Voltage Monitor Input (VBAT)
Voltage sense input. Connect to positive terminal of
battery. Bypass to GND with a minimum of 10 µF to
ensure loop stability when the battery is disconnected.
A precision internal resistor divider regulates the final
voltage on this pin to VREG.
3.6 Drive Output (VDRV)
Direct output drive of an external P-channel MOSFET
pass transistor for current and voltage regulation.
3.7 Charge Current Sense Input (VSNS)
Charge current is sensed via the voltage developed
across an external precision sense resistor. The sense
resistor must be placed between the supply voltage
(V
IN
) and the source of the external pass transistor. A
50 mΩ sense resistor produces a fast charge current of
1 A, typically.
3.8 Battery Management Input Supply
(VIN)
A supply voltage of 4.5V to 5.5V is recommended.
Bypass to GND with a minimum of 10 µF.
Pin Name Description
1 SHDN Logic Shutdown
2 GND Battery Management
0V Reference
3 MODE Charge Status Output
4I
MON
Charge Current Monitor
5V
BAT
Cell Voltage Monitor Input
6V
DRV
Drive Output
7V
SNS
Charge Current Sense Input
8V
IN
Battery Management
Input Supply