Datasheet

 
 
SLUS025F − MAY 2001 − REVISED JULY 2002
2
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DESCRIPTION (continued)
The bq2057 then begins the constant-voltage phase. The accuracy of the voltage regulation is better than ±1%
over the operating-temperature and supply-voltage ranges. For single and dual cells, the bq2057 is offered in
four fixed-voltage versions: 4.1 V, 4.2 V, 8.2 V, and 8.4 V. Charge stops when the current tapers to the charge
termination threshold, I
(TERM)
. The bq2057 automatically restarts the charge if the battery voltage falls below
the V
(RCH)
threshold.
The designer also may use the AutoComp feature to reduce charging time. This proprietary technique allows
safe and dynamic compensation for the internal impedance of the battery pack during charge.
AVAILABLE OPTIONS
PACKAGE
T
A
CHARGE REGULATION
VOLTAGE
SOIC
(SN)
TSSOP
(TS)
MSOP
†
(DGK)
4.1 V Not available bq2057TS bq2057DGK
−20°C to 70°C
4.2 V bq2057CSN bq2057CTS bq2057CDGK
−20°C to 70°C
8.2 V Not available bq2057TTS
Not available
8.4 V bq2057WSN bq2057WTS
Not available
†
Note the difference in pinout for this package.