AIC AIC1821 One-cell lithium-ion battery protection ic Datasheet

AIC1821
PRELIMINARY
ONE-CELL LITHIUM-ION BATTERY PROTECTION IC
SPEC NO: DS-1821-P1 06/07/00
n FEATURES
n DESCRIPTION
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Reduction in Board Size due to Miniature Package
SOT-25 and Less External Components.
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Ultra-Low Quiescent Current at 7µA (V CC =3.5V).
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Ultra-Low Power-Down Current at 0.4µA (V CC
=2.3V).
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Precision Overcharge Protection Voltage
The AIC1821 battery protection IC is designed to
protect lithium-ion battery from damage or
degrading the lifetime due to overcharge,
overdischarge, and/or overcurrent for one-cell
lithium-ion battery powered systems, such as
cellular phones. The ultra-small package and less
required external components make it ideal to
integrate the AIC1821 into the limited space of
battery pack.
4.35V ± 30mV for the AIC1821A
4.30V ± 30mV for the AIC1821B
4.25V ± 30mV for the AIC1821C
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4.20V ± 30mV for the AIC1821D
Built-in Delay Time Circuits for Overcharge, Overdischarge, and Overcurrent Protection.
Load Detection Function during Overcharge Mode.
Two Detection Levels for Overcurrent Protection.
The accurate ±30mV overcharging detection
voltage ensures safe and full utilization charging.
Three different specification values for overcharge
protection voltage are provided for various
protection requirements. The very low standby
current drains little current from the cell while in
storage.
n APPLICATIONS
l
Protection IC for One-Cell Lithium-Ion Battery
Pack.
n TYPICAL APPLICATION CIRCUIT
FUSE
BATT+
BATTERY
R1
100
5
C1
0.1µF
2
3
M1
SI9926
VCC
CS
4
GND
R2
OD
OC
100K
1
R3
AIC1821
10M
BATTM2 SI9926
Protection Circuit for One-Cell Lithium-Ion Battery
ANALOG INTEGRATIONS CORPORATION
www.analog.com.tw
4F, 9 Industry E. 9th Road, Science-based IndustrialPark , Hsinchu, Taiwan, R.O.C.
TEL: (8863)577-2500
FAX:(8863)577-2510
1
AIC1821
ONE-CELL LITHIUM-ION BATTERY PROTECTION IC
SPEC NO: DS-1821-P1 06/07/00
n ORDERING INFORMATION
AIC1821 XCX
ORDER NUMBER
PACKAGE TYPE
V: SOT-23-5
TOP VIEW
AIC1821ACV
AIC1821BCV
AIC1821CCV
AIC1821DCV
(SOT-23-5)
OVERCHARGE PROTECTION
A: 4.35V
B: 4.30V
C: 4.25V
D: 4.20V
PIN CONFIGURATION
VCC
CS
5
4
1
OC
2
3
GND
OD
n ABSOLUTE MAXIMUM RATINGS
Supply Voltage
.................................... … … … … … ..................................................... 18V
DC Voltage Applied on other Pins ............... … … … … … … … … … … .............................. 18V
Operating Temperature Range
Storage Temperature Range
..................................... … … … … … … . ............. -40°C~85°C
......................... … … … … … … … ..................... - 65°C~125°C
n TEST CIRCUIT
ICC
R1
5
V CC
100
CS
C1
0.1µF
R2
4
VCS
51K
2
VOD
VCC
3
GND
OD
OC
AIC1821
1
VOC
R3
10M
S1
ANALOG INTEGRATIONS CORPORATION
www.analog.com.tw
4F, 9 Industry E. 9th Road, Science-based IndustrialPark , Hsinchu, Taiwan, R.O.C.
TEL: (8863)577-2500
IOC
FAX:(8863)577-2510
2
AIC1821
ONE-CELL LITHIUM-ION BATTERY PROTECTION IC
SPEC NO: DS-1821-P1 06/07/00
n ELECTRICAL CHARACTERISTICS (Ta=25° C, unless otherwise specified.)
PARAMETER
TEST CONDITIONS
SYMBOL
MIN.
TYP.
MAX.
UNIT
Supply Current
VCC =3.5V
ICC
7
11
µA
Power-Down Current
VCC =2.3V,
I PD
0.4
1.0
µA
Overcharge Protection Voltage
AIC1821A
4.32
4.35
4.38
4.27
4.30
4.33
AIC1821C
4.22
4.25
4.28
AIC1821D
4.17
4.20
4.23
AIC1821B
V
VOCP
Overcharge Hysteresis Voltage
VHYS
230
300
370
mV
Overdischarge Protection
Voltage
VODP
2.45
2.6
2.75
V
Overdischarge Release Voltage
VODR
2.85
3.0
3.15
V
180
200
220
mV
250
500
750
mS
Overcurrent Protection Voltage
VCC =3.5V
VOIP
Overcharge Delay Time
VCC =VOCP-0.1→
TOC
VOCP + 0.1V
Overdischarge Delay Time
VCC = 2.5V →2.3V
TOD
5
10
15
mS
Overcurrent Delay Time (1)
VCC =3.5V, 1V>VCS>0.2V
TOI1
5
10
15
mS
Overcurrent Delay Time (2)
VCC =3.5V, VCS>1V
TOI2
50
µS
OC Pin Source Current
VCC =3.5V, OC pin short to
GND
IOC
240
440
µA
OD Pin Output “H” Voltage
VDH
VCC-0.1
OD Pin Output “L” Voltage
VDL
0.01
0.1
V
0.3
0.4
V
Load Dectection Threshold
Voltage
VCC =VOCP –50mV
VLD
Charge Detection Threshold
Voltage
VCC =2.3V
VCH
-0.45
ANALOG INTEGRATIONS CORPORATION
www.analog.com.tw
4F, 9 Industry E. 9th Road, Science-based IndustrialPark , Hsinchu, Taiwan, R.O.C.
TEL: (8863)577-2500
340
VCC-0.02
V
-0.3
FAX:(8863)577-2510
V
3
AIC1821
ONE-CELL LITHIUM-ION BATTERY PROTECTION IC
SPEC NO: DS-1821-P1 06/07/00
n BLOCK DIAGRAM
Wake-up Control
Enable
-0.3V
Load Detected
CS
0.3V
4
0.2V
Enable
Overcurrent
Delay Circuit
3
VCC
5
OD
1V
Overdischarge
Delay Circuit
Power-down
Control
Overcharge
Delay Circuit
1.2V
GND
2
1
OC
n PIN DESCRIPTIONS
PIN 1: OC
- PMOS open drain output for control
of the charge control MOSFET M2. In
normal mode, this PMOS turns on to
pull the gate of the MOSFET M2 to
high, then the MOSFET M2 turns on.
When overcharge occurs, this PMOS
turns off, then no current flows
through R3 and the MOSFET M2
turns off.
PIN 2: GND - Ground pin. This pin is to be
connected to the negative terminal of
the battery cell.
PIN 3: OD
- Output pin for control of the
discharge control MOSFET M1.
When overdischarge occurs, this pin
goes low to turn off the MOSFET M1
and discharging is inhibited.
PIN 4: CS
- Input pin for current sensing. Using
the sum of drain-source voltages of
the MOSFET M1 and the MOSFET
M2 (voltage between CS and GND),
it senses discharge current during
normal mode and detects whether
charge current is present during
power-down mode. It also used to
detect whether load is connected
during overcharge mode.
PIN 5: VCC - Power supply pin. This pin is to be
connected to the positive terminal of
the battery cell.
ANALOG INTEGRATIONS CORPORATION
www.analog.com.tw
4F, 9 Industry E. 9th Road, Science-based IndustrialPark , Hsinchu, Taiwan, R.O.C.
TEL: (8863)577-2500
FAX:(8863)577-2510
4
AIC1821
ONE-CELL LITHIUM-ION BATTERY PROTECTION IC
SPEC NO: DS-1821-P1 06/07/00
n APPLICATION INFORMATIONS
l
THE OPERATION
voltage drop between CS and GND. Load is
determined to be connected to the pack if the CS
pin voltage is above load detection threshold
voltage (V LD ).
Overcharge Protection
When the voltage of the battery cell exceeds the
overcharge protection voltage (V OCP) beyond the
overcharge delay time (TOC ) period, charging is
inhibited by the turning-off of the charge control
MOSFET M2. The overcharge delay time is fixed to
100mS by IC internal circuit. The overcharge
condition is released in two cases:
1. The voltage of the battery cell becomes lower
than the overcharge release voltage (V OCR or
VOCP- VHYS) through self-discharge.
2. The voltage of the battery cell falls below the
overcharge protection voltage (V OCP) and a load
is connected.
When the battery voltage is above VOCP, the
overcharge condition is never released even a load
is connected to the pack.
Power-Down after Overdischarge
When overdischarge occurs, the AIC1821 will go
into power-down mode, turning off all the timing
generation and detection circuitry to reduce the
quiescent current to 0.4µA (V CC =2.3V). At the same
time, the CS pin is pull-high to VCC through a high
resistance resistor.
Charge Detection after Overdischarge
When overdischarge occurs, the discharge control
MOSFET M1 turns off and discharging is inhibited.
However, charging is still permitted through the
parasitic diode of M1. Once the charger is
connected to the battery pack, the AIC1821
immediately turns on all the timing generation and
detection circuitry. Charging is determined to be in
progress if the voltage between CS and GND is
below charge detection threshold voltage (V CH ).
Overdischarge Protection
When the voltage of the battery cell goes below the
overdischarge protection voltage (V ODP) beyond the
overdischarge delay time (TOD ) period, discharging
is inhibited by the turning-off of the discharge
control MOSFET M1. The overdischarge delay time
defaults to 100mS. Inhibition of discharging is
immediately released when the voltage of the
battery cell becomes higher than overdischarge
release voltage (V ODR) through charging.
Overcurrent Protection
In normal mode, the AIC1821 continuously monitors
the discharge current by sensing the voltage of CS
pin. If the voltage of CS pin exceeds the overcurrent
protection voltage (V OIP) beyond the overcurrent
delay time (TOI) period, the overcurrent protection
circuit operates and discharging is inhibited by the
turning-off of the discharge control MOSFET M1.
The overcurrent condition returns to the normal
mode when the load is released and the impedance
between the BATT+ and BATT- terminals is 20MΩ
or higher.
The AIC1821 is provided with the two overcurrent
detection levels (0.2V and 1V) and the two
overcurrent delay time (TOI1 and TOI2) corresponding
to each overcurrent detection level.
Load Detection after Overcharge
The load detection function after overcharge is
implemented by detecting the CS pin voltage. Once
a load is connected to the battery pack after
overcharge, discharge current flows through the
parasitic diode of MOSFET M2 and there is a diode
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DESIGN GUIDE
Selection of External Control MOSFETs
Because the overcurrent protection voltage is
preset, the threshold current for overcurrent
detection is determined by the turn-on resistance of
the discharge control MOSFET M1. The turn-on
resistance of the external control MOSFETs can be
determined by the equation: RON =VOIP/ (2 x IT) (IT is
the overcurrent threshold current). For example, if
the overcurrent threshold current TI is designed to
be 3A, the turn-on resistance of the external control
MOSFETs must be 33mΩ. Users should be aware
that turn-on resistance of the MOSFET changes
with temperature variation due to heat dissipation. It
changes with the voltage between gate and source
as well. (Turn-on resistance of a MOSFET
increases as the voltage between gate and source
decreases). Once the turn-on resistance of the
external MOSFET changes, the overcurrent
threshold current will change accordingly.
Suppressing the Ripple and Disturbance
from Charger
To suppress the ripple and disturbance from
charger, connecting R1, C1 to VCC pin is
recommended.
Protection at CS pin
R2 is used for latch-up protection when charger is
ANALOG INTEGRATIONS CORPORATION
www.analog.com.tw
4F, 9 Industry E. 9th Road, Science-based IndustrialPark , Hsinchu, Taiwan, R.O.C.
TEL: (8863)577-2500
FAX:(8863)577-2510
5
AIC1821
ONE-CELL LITHIUM-ION BATTERY PROTECTION IC
SPEC NO: DS-1821-P1 06/07/00
connected under overdischarge condition and
overstress protection at reverse connecting of a
charger. Larger value of R2 reduces the charger
leakage current in overcharge mode, but possibly
disables the charge detection function after
overdischarge.
recommended.
Resistance
of
100KΩ
is
n TIMING DIAGRAM
l
Overcharge and Overdischarge Protection
TO C
TO C
VCC
VOCP
VOCP -VHYS
VODR
VODP
TO D
VOC
VCC
VOD
VCC
Hi-Z
Hi-Z
0V
charger connected
l
load connected
charger connected
load connected
charger connected
Overcurrent Protection (VCC=3.5V)
VCC
1V
VBATT0.2V
0V
TOI1
<TOI1
VOD
TOI2
VCC
0V
VOC
VCC
ANALOG INTEGRATIONS CORPORATION
www.analog.com.tw
4F, 9 Industry E. 9th Road, Science-based IndustrialPark , Hsinchu, Taiwan, R.O.C.
TEL: (8863)577-2500
FAX:(8863)577-2510
6
AIC1821
ONE-CELL LITHIUM-ION BATTERY PROTECTION IC
SPEC NO: DS-1821-P1 06/07/00
n PHYSICAL DIMENSIONS
l
SOT-23-5 (unit: mm)
C
D
L
H E
θ1
e
MIN
MAX
A
1.00
1.30
A1
—
0.10
A2
0.70
0.90
b
0.35
0.50
C
0.10
0.25
D
2.70
3.10
E
1.40
1.80
A
A2
e
A1
b
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SYMBOL
1.90 (TYP)
H
2.60
3.00
L
0.37
—
θ1
1°
9°
SOT-23-5 MARKING
Part No.
AIC1821ACV
AIC1821BCV
AIC1821CCV
AIC1821DCV
Marking
BL0A
BL0B
BL0C
BL0D
ANALOG INTEGRATIONS CORPORATION
www.analog.com.tw
4F, 9 Industry E. 9th Road, Science-based IndustrialPark , Hsinchu, Taiwan, R.O.C.
TEL: (8863)577-2500
FAX:(8863)577-2510
7
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