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500mA Li-ion/Polymer Battery Charger
PT0324S-1 12/21/10
1
PT8A2803
Features
• A Constant-Current / Constant-Voltage Linear
Charger for Single-Cell Li-ion/Polymer Batteries
• Integrated Pass Element and Current Sensor
• Highly-Integrated, Requiring No External FETs or
Blocking Diode
• ±0.5% 4.2V Voltage Accuracy at Room
Temperature. ±1% All Temperatures. (Available
with 4.1V and 4.36V options upon request)
• Programmable Charge Current 50mA to 500mA
• Programmable End-Of-Charge Current by Current
Recharge Algorithm
• Pre-Charge for Fully Discharged Batteries
• Less Than 1µA Leakage Current Of the Battery
when No Input Power Attached or Charger Disabled
• Power Present and Charge Status Indications
• Thermal Regulation on Charging Current to Prevent
Over-Heat
• Available with 8-pin 2x3 TDFN Package
Applications
• Cell-phones, PDA, MP3, MP4, PMP
• Standalone Chargers
• Bluetooth Applications
Description
The PT8A2803 is a fully integrated single-cell Li-
ion/Polymer battery charger. The charger operates in a
constant-current-constant-voltage (CC/CV) charging
profile without employing external FETs and blocking
diodes.
The fast charge current and end-of-charge (EOC) current
can be easily programmed by modifying two external
resistors. When the battery is deeply discharged to lower
than 2.8V, the charger firstly pre-charges the battery
with typically 20% of the programmable fast charge
current. When the charge current is reduced to the
programmed EOC current level (almost works
completely in a constant-voltage (CV) mode), an EOC
indication is displayed through the
CHG
pins.
PT8A2803 is protected by thermal regulation
technology to prevent the IC from over-heat during
charging.
Two status indication pins (
PP
and
CHG
), which are
both implemented as an open-drain outputs, can be used
to drive LEDs or work as logic interface to a
microprocessor. When no adapter is attached or when
the charger is disabled, the leakage current from battery
cell is less than 1µA typically.
Pin Assignment
TDFN 2x3
Pin Description
Pin I/O Name Descriptions
1 I/O
VIN Supply Input.
2 O
PPR
Power Present Active-Low Open Drain Power Status Indicator
3 O
CHG
Charge Active-Low Open Drain Charge Status Indicator
4 I
EN
Enable Active-Low Input
5 I/O
GND Ground
6 I
IMIN End-Of-Charge Current Setting Input
7 I
IREF Charge Current Setting Input
8 O
BAT Battery Terminal
PPR
2
VIN
1
3
4
5
6
7
8
CHG
EN
IREF
BAT
IMIN
GND
