Datasheet

© 2007-2011 Microchip Technology Inc. DS22071B-page 15
MCP73837/8
4.0 DEVICE OVERVIEW
The MCP73837/8 devices are simple, yet fully integrated linear charge management controllers. Figure 4-1 depicts the
operational flow algorithm.
FIGURE 4-1: Flow Chart.
SHUTDOWN MODE*
V
DD
< V
BAT
- 100 mV
V
DD
< V
STOP
STAT1 = Hi-Z
STAT2 = Hi-Z
PG = Hi-Z
PRECONDITIONING MODE
Charge Current = I
PREG
STAT1 = LOW
STAT2 = Hi-Z
PG = LOW
Timer Reset
FAST CHARGE MODE
Charge Current = I
REG
STAT1 = LOW
STAT2 = Hi-Z
PG = LOW
Timer Enabled
CONSTANT VOLTAGE MODE
Charge Voltage = V
REG
STAT1 = LOW
STAT2 = Hi-Z
PG = LOW
V
BAT
> V
PTH
V
BAT
= V
REG
V
BAT
< V
RTH
V
BAT
> V
PTH
CHARGE COMPLETE MODE
No Charge Current
STAT1 = Hi-Z
STAT2 = LOW
PG = LOW
I
BAT
< I
TERM
Timer Expired
V
BAT
< V
PTH
STANDBY MODE *
V
BAT
> (V
REG
+100 mV)
PROG > 200k Ω
STAT1 = Hi-Z
STAT2 = Hi-Z
PG = LOW
* Continuously Monitored
TEMPERATURE FAULT
No Charge Current
STAT1 = Hi-Z
STAT2 = Hi-Z
PG = LOW
Timer Suspended
SYSTEM TEST (LDO) MODE
V
THERM
> (V
DD
-100 mV)
STAT1 = LOW
STAT2 = LOW
PG = LOW
Timer Suspended
TIMER FAULT
No Charge Current
STAT1 = Hi-Z
STAT2 = Hi-Z
PG = LOW
Timer Suspended
Timer Expired