19-1465; Rev 2; 12/03
Advanced Lithium-Ion
Battery-Pack Protector
General Description
The MAX1666 provides complete protection against over-
voltage, undervoltage, overcharge current, overdischarge
current, and cell mismatch for 2-cell to 4-cell lithium-ion
(Li+) battery packs. The voltage of each cell in the battery
pack is checked and compared to the programmable
threshold and to the other cells in the pack.
The MAX1666 protects the battery pack in an overcurrent
condition by disconnecting the pack from the load at a pro-
grammable limit. On-chip power MOSFET drivers control
external P-channel MOSFETs to disconnect the cells from
external terminals when faults occur.
The MAX1666 employs a unique timing scheme that
allows three modes of operation for optimal performance
and battery power conservation. The MAX1666 can oper-
ate in a stand-alone configuration or in conjunction with a
microcontroller. It is available in four versions: the S ver-
sion monitors two Li+ cells, the A and V versions monitor
three cells, and the X version monitors four cells. When
the charge path is disabled by the charge control pin, the
MAX1666A reduces current consumption compared to
the MAX1666S/V/X.
Features
♦
Overvoltage Protection
Programmable Limits from +4.0V to +4.4V
Accurate to ±0.5%
♦
Undervoltage Protection
Programmable Limits from +2.0V to +3.0V
Accurate to ±2.5%
♦
Cell Mismatch Protection
Programmable Limits from 0 to 500mV
Accurate to ±10%
♦
Overcharge Current Protection
♦
Overdischarge Current Protection
♦
Low 30µA (typ) Operating Supply Current
♦
Low 1µA (max) Standby Current
♦
+28V (max) Input Voltage
♦
Available in Small 16-Pin QSOP (MAX1666S) and
20-Pin QSOP (MAX1666A/V/X) Packages
MAX1666A/S/V/X
Applications
2/3/4-Cell Lithium-Ion Battery Pack
PART
MAX1666SEEE
MAX1666AEEP
PART
MAX1666S
MAX1666A/V
MAX1666X
NUMBER OF Li+ CELLS
2
3
4
MAX1666VEEP
MAX1666XEEP
Ordering Information
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
16 QSOP
20 QSOP
20 QSOP
20 QSOP
Selector Guide
Typical Operating Circuits appear at end of data sheet.
Pin Configurations
TOP VIEW
SRC 1
DSO 2
TKO 3
CGO 4
B2P 5
BIP 6
GND 7
PKN 8
16 V
CC
15 REF
14 OVA
SRC 1
DSO 2
TKO 3
CGO 4
B3P 5
B3P 6
B2P 7
B1P 8
GND 9
PKN 10
20 UVO
19 V
CC
18 REF
17 OVA
SRC 1
DSO 2
TKO 3
CGO 4
B4P 5
B3P 6
B2P 7
B1P 8
GND 9
PKN 10
20 UVO
19 V
CC
18 REF
17 OVA
MAX1666S
13 UVA
12 MMA
11 PKF
10 CGI
9
DSI
MAX1666A/V
16 UVA
15 MMA
14 WRN
13 PKF
12 CGI
11 DSI
MAX1666X
16 UVA
15 MMA
14 WRN
13 PKF
12 CGI
11 DSI
QSOP
QSOP
QSOP
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Advanced Lithium-Ion
Battery-Pack Protector
MAX1666A/S/V/X
ABSOLUTE MAXIMUM RATINGS
SRC,
DSO, TKO, CGO,
UVO,
PKF, WRN
to GND ...-0.3V to +28V
V
CC
, REF, OVA, UVA, MMA to GND ........................-0.3V to +6V
B4P to B3P ...............................................................-0.3V to +6V
B3P to B2P ...............................................................-0.3V to +6V
B2P to B1P ...............................................................-0.3V to +6V
B1P to GND ..............................................................-0.3V to +6V
PKN to GND...........................................................................±2V
V
CC
,
CGI, DSI
to PKN...............................................-0.3V to +6V
Continuous Power Dissipation (T
A
= +70°C)
16-Pin QSOP (derate 8.3mW/°C above +70°C)...........667mW
20-Pin QSOP (derate 9.1mW/°C above +70°C)...........727mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
SRC
= 16V, each cell voltage V
CELL
= 3.6V, 330kΩ load at REF,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at
T
A
= +25°C.)
PARAMETER
Charge-Mode Detection
Threshold
SYMBOL
V
SRC
- V
B_P
V
SRC
- V
B_P
= 1V, V
CGI
= V
DSI
= GND
SRC Supply Current
MAX1666A only, V
SRC
- V
B3P
= 1V, V
CGI
=
3V, V
DSI
= GND
MAX1666A only, V
SRC
- V
B3P
= 1V, V
DSI
=
3V, V
CGI
= GND
Supply Current
Shutdown Supply Current
V
CC
Output Voltage
V
CC
Undervoltage-Lockout
Threshold
Reference Output Voltage
Overvoltage Threshold
Overvoltage-Threshold
Hysteresis
UVA = GND
Undervoltage Threshold
Undervoltage-Threshold
Hysteresis
Cell voltage
falling
V
UVA
= V
REF
/ 2
UVA = REF
2.925
1.950
V
REF
Pulse on
Cell voltage
rising
OVA = GND
V
OVA
= V
REF
/ 2
OVA = REF
4.378
3.980
I
SUP
I
SHDN
V
CC
R
LOAD
≥
665Ω, 2V < V
CELL
< 4.4V
3.09
2.7
3.25
2.85
1.221
4.000
4.2
4.400
200
2.000
2.500
3.000
100
3.075
mV
2.050
V
4.422
mV
4.020
V
No faults, long-time average current from
the top battery terminal B_P
CONDITIONS
MIN
1
2
2
2
30
10
5
5
45
1
3.41
3.0
µA
µA
V
V
V
µA
TYP
MAX
UNITS
V
2
_______________________________________________________________________________________
Advanced Lithium-Ion
Battery-Pack Protector
ELECTRICAL CHARACTERISTICS (continued)
(V
SRC
= 16V, each cell voltage V
CELL
= 3.6V, 330kΩ load at REF,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at
T
A
= +25°C.)
PARAMETER
WRN
Early-Warning Threshold
WRN
Early-Warning-Threshold
Hysteresis
OVA, UVA, MMA Input Current
Cell Mismatch Threshold
PKN to GND Overdischarge-
Current Threshold
PKN to GND Overcharge-Current
Threshold
Overcurrent Fault-Timer Delay
Overdischarge/Overcharge-
Current Fault-Blanking Time
DSO, CGO,
UVO Output Sink
Current
DSO, CGO
Output Source
Current
DSO, CGO,
UVO Leakage
Current
TKO
Pulldown Resistance,
MAX1666S/V/X
TKO
Sink Current, MAX1666A
Only
TKO
Leakage Current,
MAX1666A Only
Minimum B3P Voltage for
TKO
Low, MAX1666A Only
TKO
Source Current
DSI, CGI
Input High Voltage
DSI, CGI
Input Low Voltage
DSI, CGI
Input Current
WRN
Sink Current
PKF
Sink Current
PKF, WRN
Leakage Current
Undervoltage, Overvoltage, or
Mismatch Fault, to
DSO, CGO,
TKO
Transition Delay
t
F-DELAY
V
TKO
= 16V
V
TKO
= 16V, V
CGI
= 3V
V
SRC
= V
B3P
+ 1V, I
TKO
= 0.5mA
TKO
= GND
Referenced to PKN
Referenced to PKN
V
DSI
, V
CGI
= 5V
Fault condition, V
WRN
= 0.4V
Fault condition, V
PKF
= 0.4V
V
PKF
= V
WRN
= 27V
Fault persistent for four consecutive sample
periods
180
320
2
4
4
8
0.2
460
1
2
0.45
1
2.4
8
t
P-DELAY
t
I-DELAY
No faults, V
DSO
= V
CGO
= V
UVO
= 1V to
27V
V
DSO
= V
SRC
- 4V and V
CGO
= V
SRC
- 4V,
fault condition
V
DSO
= V
CGO
= V
UVO
= 27V, fault condition
100
1
200
2.5
1
3.6
OVA, UVA, MMA = REF
MMA = GND
All cells > 2V
V
MMA
= V
REF
/ 2
MMA = REF
±450
270
-220
330
1.6
20
2
SYMBOL
CONDITIONS
Above undervoltage threshold, cell voltage
falling
MIN
TYP
100
200
0.1
±0
±250
±500
300
-200
550
2.4
30
10
0.2
±550
330
-180
770
3.2
40
mV
mV
ms
ms
µA
mA
µA
kΩ
mA
µA
V
mA
V
V
µA
mA
mA
µA
ms
mV
20
MAX
UNITS
mV
mV
nA
MAX1666A/S/V/X
_______________________________________________________________________________________
3
Advanced Lithium-Ion
Battery-Pack Protector
MAX1666A/S/V/X
ELECTRICAL CHARACTERISTICS
(V
SRC
= 16V, each cell voltage V
CELL
= 3.6V, 330kΩ load at REF,
T
A
= -40°C to +85°C,
unless otherwise noted.) (Note 1)
PARAMETER
Charge-Mode Detection
Threshold
SYMBOL
V
SRC
- V
B_P
V
SRC
- V
B_P
= 1V, V
CGI
= V
DSI
= GND
SRC Supply Current
MAX1666A only, V
SRC
- V
B3P
= 1V, V
CGI
=
3V, V
DSI
= GND
MAX1666A only, V
SRC
- V
B3P
= 1V, V
DSI
=
3V, V
CGI
= GND
Supply Current
Shutdown Supply Current
V
CC
Output Voltage
V
CC
Undervoltage-Lockout
Threshold
Overvoltage Threshold
Undervoltage Threshold
OVA, UVA, MMA Leakage
Cell Mismatch Threshold
PKN to GND Overdischarge-
Current Threshold
PKN to GND Overcharge-Current
Threshold
Overcurrent Fault-Timer Delay
Overdischarge/Overcharge-
Current Fault-Blanking Time
DSO, CGO,
UVO Output Sink
Current
DSO, CGO
Output Source
Current
DSO, CGO,
UVO Leakage
Current
t
P-DELAY
t
I-DELAY
No faults; V
DSO
, V
CGO
, V
UVO
= 1V to 27V
V
DSO
= V
SRC
- 4V and V
CGO
= V
SRC
- 4V,
fault condition
V
DSO
= V
CGO
= V
UVO
= 27V, fault condition
OVA = GND
OVA = REF
UVA = GND
UVA = REF
OVA, UVA, MMA = REF
All cells > 2V, MMA = REF
±450
270
-220
330
1.6
20
2
0.2
I
SUP
I
SHDN
V
CC
R
LOAD
≥
665Ω, 2V < V
CELL
< 4.4V
3.09
2.7
3.975
4.373
1.950
2.925
No faults, long-time average current from
the top battery terminal B_P
CONDITIONS
MIN
1
10
5
5
45
1
3.41
3.0
4.025
4.427
2.050
3.075
20
±550
330
-180
770
3.2
40
µA
µA
V
V
V
V
nA
mV
mV
mV
ms
ms
µA
mA
µA
µA
TYP
MAX
UNITS
V
4
_______________________________________________________________________________________
Advanced Lithium-Ion
Battery-Pack Protector
ELECTRICAL CHARACTERISTICS
(V
SRC
= 16V, each cell voltage V
CELL
= 3.6V, 330kΩ load at REF,
T
A
= -40°C to +85°C,
unless otherwise noted.) (Note 1)
PARAMETER
TKO
Pulldown Resistance,
MAX1666S/V/X
TKO
Sink Current,
MAX1666A Only
Minimum B3P Voltage for
TKO
Low
TKO
Source Current
DSI, CGI
Input High Voltage
DSI, CGI
Input Low Voltage
DSI, CGI
Input Current
WRN
Sink Current
PKF
Sink Current
PKF, WRN
Leakage Current
Undervoltage, Overvoltage, or
Mismatch Fault, to
DSO, CGO,
TKO
Transition Delay
t
F-DELAY
V
TKO
= 16V
V
SRC
= V
B3P
+ 1V, I
TKO
= 0.5mA
TKO
= GND
Referenced to PKN
Referenced to PKN
V
DSI
= V
CGI
= 5V
Fault condition, V
WRN
= 0.4V
Fault condition, V
PKF
= 0.4V
V
PKF
= V
WRN
= 27V
Fault persistent for four consecutive sample
periods
180
2
4
0.2
460
1
2
0.45
1
SYMBOL
CONDITIONS
MIN
100
1
3.6
TYP
MAX
UNITS
kΩ
mA
V
mA
V
V
µA
mA
mA
µA
ms
MAX1666A/S/V/X
Note 1:
Specifications to -40°C are guaranteed by design, not production tested.
_______________________________________________________________________________________
5