Datasheet

MCP73841/2/3/4
DS21823D-page 10  2003-2013 Microchip Technology Inc.
3.0 PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 3-1.
TABLE 3-1: PIN DESCRIPTION TABLE
3.1 Charge Current Sense Input
(SENSE)
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
DD
) and the external pass transistor (Q1). A 220 m
sense resistor produces a fast charge current of
500 mA, typically.
3.2 Battery Management Input Supply
(V
DD
)
A supply voltage of [V
REG
(Typ) + 0.3V] to 12V is
recommended. Bypass to V
SS
with a minimum of
4.7 µF.
3.3 Charge Status Output (STAT1)
Current limited, open-drain drive for direct connection
to a LED for charge status indication. Alternatively, a
pull-up resistor can be applied for interfacing to a host
microcontroller.
3.4 Logic Enable (EN)
Input to force charge termination, initiate charge, clear
faults or disable automatic recharge.
3.5 Cell Temperature Sensor Bias
(THREF)
Voltage reference to bias external thermistor for
continuous cell temperature monitoring and
prequalification.
3.6 Cell Temperature Sensor Input
(THERM)
Input for an external thermistor for continuous cell-
temperature monitoring and pre-qualification. Apply a
voltage equal to 0.85V to disable temperature-sensing.
3.7 Timer Set (TIMER)
All safety timers are scaled by C
TIMER
/0.1 µF.
3.8 Battery Management 0V Reference
(V
SS
)
Connect to negative terminal of battery.
3.9 Battery Voltage Sense (V
BAT
)
Voltage sense input. Connect to positive terminal of
battery. Bypass to V
SS
with a minimum of 4.7 µF to
ensure loop stability when the battery is disconnected.
A precision internal resistor divider regulates the final
voltage on this pin to V
REG
.
3.10 Drive Output (DRV)
Direct output drive of an external P-channel MOSFET
for current and voltage regulation.
MCP73841,
MCP73842
Pin No.
MCP73843,
MCP73844
Pin No.
Name Function
1 1 SENSE Charge Current Sense Input
22V
DD
Battery Management Input Supply
3 3 STAT1 Charge Status Output
4 4 EN Logic Enable
5 — THREF Cell Temperature Sensor Bias
6 — THERM Cell Temperature Sensor Input
75TIMERTimer Set
86V
SS
Battery Management 0V Reference
97V
BAT
Battery Voltage Sense
10 8 DRV Drive Output