Datasheet

2008-2013 Microchip Technology Inc. DS20002090C-page 21
MCP73871
4.0 DEVICE OVERVIEW
The MCP73871 device is a simple but fully integrated
linear charge management controller with system load
sharing feature. Figure 4-1 depicts the operational flow
algorithm.
FIGURE 4-1: MCP73871 Device Flow Chart.
SHUTDOWN MODE *
V
DD
< V
UVLO
V
DD
< V
BAT
STAT1 = Hi-Z
STAT2 = Hi-Z
PG = Hi-Z
PRECONDITIONING MODE
Charge Current = I
PREG
STAT1 = LOW
STAT2 = Hi-Z
PG = LOW
Timer Reset
CONSTANT VOLTAGE MODE
Charge Voltage = V
REG
STAT1 = LOW
PG = LOW
V
BAT
> V
PTH
CHARGE COMPLETE MODE
No Charge Current
STAT1 = Hi-Z
STAT2 = LOW
PG = LOW
Timer Reset
I
BAT
< I
TERM
Timer Expired
V
BAT
< V
PTH
STANDBY MODE *
V
BAT
> (V
REG
+ 100 mV)
CE = LOW
STAT1 = Hi-Z
STAT2 = Hi-Z
PG = LOW
* Continuously Monitored
TEMPERATURE FAULT
No Charge Current
STAT1 = LOW
STAT2 = LOW
PG = LOW
Timer Suspended
TIMER FAULT
No Charge Current
STAT1 = LOW
STAT2 = LOW
PG = LOW
Timer Expired
LBO *
V
IN
< V
BAT
STAT1 = LOW
STAT2 = Hi-Z
PG = Hi-Z
V
BAT
> V
PTH
STAT2 = Hi-Z
Timer Reset
FAST CHARGE MODE
Charge Current = I
REG
STAT1 = LOW
STAT2 = Hi-Z
PG = LOW
Timer Enabled