© 2007 Microchip Technology Inc.

DS22071A-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

V

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

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