Datasheet

© 2007 Microchip Technology Inc. DS22036B-page 9
MCP73811/2
3.0 PIN DESCRIPTION
The descriptions of the pins are listed in Table 3-1.
TABLE 3-1: PIN FUNCTION TABLES
3.1 Charge Enable Input (CE)
A logic High enables battery charging. A logic Low
disables battery charging. The charge enable input is
compatible with 1.8V logic.
3.2 Battery Management 0V Reference
(V
SS
)
Connect to negative terminal of battery and input
supply.
3.3 Battery Charge Control Output
(V
BAT
)
Connect to positive terminal of battery. Drain terminal
of internal P-channel MOSFET pass transistor. Bypass
to V
SS
with a minimum of 1 µF to ensure loop stability
when the battery is disconnected.
3.4 Battery Management Input Supply
(V
DD
)
A supply voltage of [V
REG
(typ.) + 0.3V] to 6V is
recommended. Bypass to V
SS
with a minimum of 1 µF.
3.5 Current Regulation Set (PROG)
For the MCP73811, the current regulation set input
(PROG) functions as a digital input selection. A logic
Low selects a 85 mA charge current; a logic High
selects a 450 mA charge current.
For the MCP73812, the charge current is set by placing
a resistor from PROG to V
SS
.
Pin Number
Symbol Function
SOT-23-5
1 CE Active High Charge Enable
2V
SS
Battery Management 0V Reference
3V
BAT
Battery Charge Control Output
4V
DD
Battery Management Input Supply
5 PROG Current Regulation Set and Charge Control Enable