a
Lithium-Ion
Battery Charger
ADP3820
PRELIMINARY
FEATURES
±1% Accuracy
800 µA Quiescent Current
Shutdown Current : 1µA (Typical)
Stable with 10 µF Load Capacitor
4.5 V to 15 V Input Operating Range
Integrated Reverse Leakage Protection
6 Lead SOT-23 Package
Programmable Charge Current
–20°C to 85°C Ambient Temperature Range
Internal Gate-to-Source Protective Clamp
3 µA Reverse Leakage
FUNCTIONAL BLOCK DIAGRAM
+
50MV
IS
APPLICATIONS
LiIon Battery Chargers
Desktop Computers
Handheld Instruments
Cellular Telephones
Battery Operated Devices
VREF
G
VOUT
GND
GENERAL DESCRIPTION
The ADP3820 is a precision LiIon battery charge controller
which can be used with an external Power PMOS device to
form a 2 chip low cost, low dropout linear charger. It is available
in two voltage options to accommodate LiIon batteries with
coke or graphite anodes. The ADP3820's high accuracy (±1%)
low shutdown current (1 µA) and easy charge current programming make this device especially attractive as a battery charge
controller.
Charge current can be set by an external resistor or printed
circuit board trace resistance. For example, 100 mΩ of board
metal trace resistance can be used to set the charge current to
0.4 A. Additional features of this device include foldback
current limit, overload recovery, and a gate-to-source voltage
clamp to protect the external MOSFET. The proprietary circuit
also minimizes the reverse leakage current from the battery if the
input voltage of the charger is disconnected. This feature
eliminates the need for an external serial blocking diode.
VIN
BIAS
EN
RS
VIN
C1
1µF
R1
10kΩ
+
-
NDP6020P
VOUT
100mΩ
LiIon
Battery
G
IS
OUT
IN
ADP3820-xx
EN
10µF
GND
Figure 1. Typical LiIon Charger Application Circuit
The ADP3820 operates with a wide input voltage range from
4.5 V to 15 V. It is specified over the industrial temperature
range of -20°C to 85°C and is available in the ultra small 6 pin
surface mount SOT-23 package.
COMPANY CONFIDENTIAL
REV. 9 1/27/98
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
Preliminary specifications subject to change without notice.
One Technology Way, P.O. Box 9106, Norwood. MA 02062-9106, U.S.A.
Tel: 617/329-4700
World Wide Web Site: http://www.analog.com
Fax: 617/326-8703
© ANALOG DEVICES, INC., 1998
ADP3820-SPECIFICATIONS
Parameter
(VIN =( V OUT +1 V), TA = -20°C to 85°C, unless otherwise noted)
Conditions
Symbol
Min
VIN
VIN = VOUT + 1 V to 15 V
VEN = 2 V
VOUT
VEN = 0 V
VEN = 2 V
IGND
IGND
INPUT VOLTAGE
OUTPUT VOLTAGE ACCURACY
QUIESCENT CURRENT
Shutdown Mode
Normal Mode
Max
Units
VOUT+1
15
V
-1
+1
%
1
800
10
TBD
µA
µA
8
10
V
GATE TO SOURCE CLAMP VOLTAGE
1
GATE DRIVE MINIMUM VOLTAGE
Typ
0.7
GATE DRIVE CURRENT(SINK/SOURCE)
V
1
 ∆VGS 

 ∆VOUT 
GAIN 
mA
80
CURRENT LIMIT THRESHOLD
VOLTAGE
TA = 25°C
VIN - V IS
LOAD REGULATION
dB
40
60
mV
IOUT = 10 mA to 1 A,
Circuit of Figure 1
–10
10
mV
LINE REGULATION
VIN = VOUT + 1 V to 15 V
IOUT = 0.1 A
Circuit of Figure 1
–10
10
mV
SHUTDOWN INPUT VOLTAGE
VIH
VIL
VEN
0.4
V
V
SHUTDOWN INPUT CURRENT
VEN = 0 V to 5 V
IEN
+2
µA
OUTPUT REVERSE LEAKAGE
CURRENT
VIN = Floating
IDISCH
5
µA
2.0
–2
3
NOTE
1
Provided gate-to-source clamp voltage is not exceeded.
Specifications subject to change without notice.
Absolute Maximum Ratings*
Input Voltage, VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 V
Enable Input Voltage . . . . . . . . . . . . . . . 0.3 V to (V IN + 0.3 V)
Operating Junction Temperature Range . . . -55°C to +125°C
Storage Temperature Range . . . . . . . . . . . . . –65°C to +150°C
Load Temperature (Soldering, 10 sec) . . . . . . . . . . . . +300°C
Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . . . +215°C
Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . . . +220°C
ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .TBD V
* This is a stress rating only; operation beyond these limits can
cause the device to be permanently damaged.
COMPANY CONFIDENTIAL
Preliminary specifications subject to change without notice.
–2–
REV. 9
ADP3820
ORDERING GUIDE
Model
Voltage Output
ADP3820ART-4.1
ADP3820ART-4.2
4.1 V
4.2 V
PIN CONFIGURATION
Pkg Option*
6 IS
EN 1
ADP3820
5 IN
TOP VIEW
(Not
to
Scale)
4 G
OUT 3
GND 2
SOT-23 6-Lead
SOT-23 6-Lead
* SOT-23 = Surface Mount Package.
SOT-23
PIN FUNCTION DESCRIPTIONS
Pin
Name
Function
1
EN
2
3
GND
VOUT
4
G
5
VIN
6
IS
Enable. Pulling this pin to a logic Hi
or tying it to the input voltage will
enable the output. Pulling this pin
low will shutdown the controller.
Device Ground.
Output Voltage Sense. This pin is
connected to the MOSFET’s drain
and directly to the battery. Bypass to
ground with a 10 µF or larger
capacitor.
Gate Drive for the external MOSFET.
Input Voltage. This is also the positive
terminal connection of the current
limit resistor.
Current Sense. It is connected to the
more negative terminal of the current
limit resistor as well as the Power
MOSFET's source pin. IS pin must
be tied to the VIN pin if the current
limit resistor is not used.
COMPANY CONFIDENTIAL
Preliminary specifications subject to change without notice.
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection.
Although the ADP3820 features proprietary ESD protection circuitry, permanent damage may
occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD
precautions are recommended to avoid performance degradation or loss of functionality.
REV. 9
–3–
WARNING!
ESD SENSITIVE DEVICE