bq2057, bq2057C

bq2057T, bq2057W

SLUS025F − MAY 2001 − REVISED JULY 2002

7

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APPLICATION INFORMATION

CC

SNS

VCC

VSS

COMP

BAT

TS

STAT

bq2057

VCC

R1

1 k

Ω

D1

R2

2 k

Ω

RT2

RT1

VCC

TEMP

PACK−

PACK+

C1

0.1

µF

NTC

Battery

Pack

C2

0.1

µF

DC+

GND

RSNS

0.2

Ω

Q1

FZT788B

Figure 1. Low Dropout Single- or Two-Cell Li-Ion/Li-Pol Charger

functional description

The bq2057 is an advanced linear charge controller for single or two-cell Li-Ion or Li-Pol applications. Figure 1

shows the schematic of charger using a PNP pass transistor. Figure 2 is an operational state diagram, and

Figure 3 is a typical charge profile. Figure 4 shows the schematic of a charger using P-channel MOSFET.