bq24200, bq24201, bq24202
bq24203, bq24204, bq24205
SLUS501A 鈥?OCTOBER 2001
SINGLE CHIP LI ION AND LI POL CHARGE MANAGEMENT IC
FOR CURRENT LIMITED APPLICATIONS
FEATURES
D
Designed Specifically to Work With
D
D
D
D
D
D
D
D
Current-Limited Wall Supplies
Ideal for Low Dropout Charger Design for
Single-Cell Li-Ion Packs With Coke or
Graphite Anodes
Integrated PowerFET for 500 mA
Integrated Voltage Regulation With 0.5%
Accuracy
Battery Insertion and Removal Detection
Charge Termination by Minimum Current and
Time
Pre-Charge Conditioning With Safety Timer
Sleep Mode for Low-Power Consumption
Charge Status Output for LED or Host
Processor Interface Indicates
Charge-in-Progress, Charge Completion, and
Fault Conditions
Optional Temperature Monitoring Before and
During Charge
Small, 8-Pin Power-Pad MSOP Package
DESCRIPTION
The bq2420x series are simple Li-Ion linear
charge management devices targeted at low-cost
and space limited charger applications. The
bq2420x series offer integrated powerFET,
high-accuracy voltage regulation, temperature
monitoring, charge status, and charge
termination, in a single monolithic device.
The bq2420x is designed to work with a
current-limited wall-mount transformer and
therefore does not provide any current regulation.
However, these devices offer a fixed internal
current limit to prevent damage to the internal
powerFET. A time-limited pre-conditioning phase
is provided to condition deeply discharged cells.
Once the battery reaches the charge voltage, the
high accuracy voltage regulation loop takes over
and completes the charge cycle. Charge is
terminated based on minimum current. An internal
charge timer provides a backup safety for charge
termination.
Other standard features include an automatic
sleep mode activated when V
CC
falls below the
battery voltage and a recharge feature activated
when the battery voltage falls below the V
RCH
threshold.
In addition to the standard features, the core
product provides two additional enhancements:
temperature monitoring and status display. The
temperature-sense circuit continuously measures
battery temperature using an external thermistor
and inhibits charge until the battery temperature is
within the user鈥揹efined thresholds. The STAT pin
indicates three conditions of operation of the
charger. These conditions are
charge-
in-progress, charge complete,
and
fault.
This
output can be used to drive an LED or an interface
to a microcontroller.
D
D
TYPICAL APPLICATION
bq24202DGN
DC+
1
C1
IN
OUT
8
C1
2
VCC
BAT
7
+
3
DC鈥?/div>
R1
STAT
CE
6
4
VSS
N/C
5
BATTERY PACK
UDG鈥?1111
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
Copyright
铮?/div>
2001, Texas Instruments Incorporated
www.ti.com
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