19-2535; Rev 1; 12/05
Low-Power, Single-/Dual-Level Battery Monitors
with Hysteresis and Integrated µP Reset
General Description
The MAX6439–MAX6442 are a family of ultra-low-power
battery monitors with integrated microprocessor (µP)
supervisors. The battery monitors are offered with sin-
gle or dual low-battery output options that can be used
to signal when the battery is OK (enabling full system
operation), when the battery is low (for low-power sys-
tem operation), and when the battery is dead (to dis-
able system operation). These devices also have an
independent µP supervisor that monitors V
CC
and pro-
vides an active-low reset output. A manual reset func-
tion is available to reset the µP with a push-button. No
external components are required.
The MAX6439–MAX6442 are offered with several facto-
ry-trimmed low-battery threshold combinations ideal for
single-cell lithium-ion (Li+) or multicell alkaline/NiCd/
NiMH applications. When the battery voltage drops
below each specified low threshold, the low-battery out-
puts are asserted to alert the system. When the voltage
rises above the specified high thresholds, the outputs
are deasserted after a 150ms minimum timeout period,
ensuring the voltages have stabilized before power cir-
cuitry is activated or providing microprocessor reset tim-
ing. The low and high thresholds provide hysteresis in
battery-operated systems to eliminate output chattering.
The MAX6439/MAX6440 offer factory-trimmed battery
monitors with a single output. The MAX6441/MAX6442
offer factory-trimmed battery monitors with dual outputs.
All battery monitors have open-drain low-battery outputs.
The MAX6439–MAX6442 monitor system voltages
(V
CC
) from 1.8V to 3.3V with seven fixed reset threshold
options. Each device is offered with two minimum reset
timeout periods of 150ms or 1200ms. The MAX6439/
MAX6441 are offered with an open-drain
RESET
output
and the MAX6440/MAX6442 are offered with a push-
pull
RESET
output.
The MAX6439–MAX6442 are offered in a SOT23 pack-
age and are fully specified over a -40°C to +85°C temp-
erature range.
Features
♦
Factory-Trimmed V
BATT
Threshold Options for
Monitoring Single-Cell Li+ or Multicell
Alkaline/NiCd/NiMH Applications
♦
Immune to Short Battery Voltage Transients
♦
Low Current (2.5µA typ at 3.6V)
♦
Single and Dual Low-Battery Output Options
♦
150ms Minimum
LBO
Timeout Period
♦
Independent µP Reset with Manual Reset
♦
Factory-Set Reset Thresholds for Monitoring V
CC
from 1.8V to 3.3V
♦
Available with 150ms (min) and 1.2s (min) V
CC
Reset Timeout Period Options
♦
-40°C to +85°C Operating Temperature Range
♦
Small 6- and 8-Pin SOT23 Packages
♦
No External Components
MAX6439–MAX6442
Ordering Information
PART
MAX6439UT_
_ _D_-T
MAX6440UT_
_ _D_-T
MAX6441KA_
_ _D_-T
MAX6442KA_
_ _D_-T
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
6 SOT23-6
6 SOT23-6
8 SOT23-8
8 SOT23-8
Note:
The first two “_ _” are placeholders for the battery moni-
tor voltage levels. Desired threshold levels are set by the part
number suffix found in Tables 1 and 2. The third “_” is the V
CC
reset threshold level suffix found in Table 3. The “_” after the D
is a placeholder for the reset timeout period suffix found in
Table 4. All devices are available in tape-and-reel only. There
is a 2500-piece minimum order increment for standard ver-
sions. Sample stock is typically held on standard versions only.
Nonstandard versions require a minimum order increment of
10,000 pieces. Contact factory for availability.
Devices are available in both leaded and lead-free packaging.
Specify lead-free by replacing “-T” with “+T” when ordering.
Applications
Battery-Powered Systems (Single-Cell Li+ or
Two-/Three-Cell NiMH, NiCd, Alkaline)
Cell Phones/Cordless Phones
Portable Medical Devices
Electronic Toys
Pagers
PDAs
MP3 Players
LBO
3
Pin Configurations
TOP VIEW
V
BATT
1
6
V
CC
MR
2
MAX6439
MAX6440
5
GND
4
RESET
SOT23-6
Pin Configurations continued at end of data sheet.
1
________________________________________________________________
Maxim Integrated Products
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.
Low-Power, Single-/Dual-Level Battery Monitors
with Hysteresis and Integrated µP Reset
MAX6439–MAX6442
ABSOLUTE MAXIMUM RATINGS
V
BATT
, V
CC
to GND.................................................-0.3V to +6V*
Open-Drain
LBO, LBOH, LBOL, LBOLH
to GND ...-0.3V to +6V*
Open-Drain
RESET
to GND ....................................-0.3V to +6V*
Push-Pull
RESET
to GND............................-0.3V to (V
CC
+ 0.3V)
MR
to GND .................................................-0.3V to (V
CC
+ 0.3V)
Input/Output Current, All Pins .............................................20mA
Continuous Power Dissipation (T
A
= +70°C)
6-Pin SOT23 (derate 8.7mW/°C above +70°C)............695mW
8-Pin SOT23 (derate 8.9mW/°C above +70°C)............714mW
*Applying
7V for a duration of 1ms does not damage the device.
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.
Operating Temperature Range .......................... -40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
ELECTRICAL CHARACTERISTICS
(V
BATT
= 1.2V to 5.5V, V
CC
= 1.2V to 5.5V, T
A
= -40°C to +85°C, unless otherwise specified. Typical values are at T
A
= +25°C.) (Note1)
PARAMETER
V
BATT
Operating Voltage Range
V
CC
Operating Voltage Range
V
CC
+ V
BATT
Supply Current
V
BATT
THRESHOLDS
MAX6439UT_ J, MAX6440UT_ J
MAX6439UT_ I, MAX6440UT_ I
MAX6439UT_ H, MAX6440UT_ H
HTH Threshold
HTH
MAX6439UT_ G, MAX6440UT_ G
MAX6439UT_ T, MAX6440UT_ T
MAX6439UT_ S, MAX6440UT_ S
MAX6439UT_ R, MAX6440UT_ R
MAX6439UT_ Q, MAX6440UT_ Q
MAX6439UTF, MAX6440UTF
MAX6439UTE, MAX6440UTE
MAX6439UTD, MAX6440UTD
MAX6439UTC, MAX6440UTC
MAX6439UTB, MAX6440UTB
LTH Threshold
LTH
MAX6439UTA, MAX6440UTA
MAX6439UTP, MAX6440UTP
MAX6439UTO, MAX6440UTO
MAX6439UTN, MAX6440UTN
MAX6439UTM, MAX6440UTM
MAX6439UTL, MAX6440UTL
MAX6439UTK, MAX6440UTK
3.510
3.413
3.315
3.218
2.535
2.438
2.340
2.243
3.023
2.925
2.828
2.730
2.633
2.535
2.048
1.950
1.853
1.755
1.658
1.560
3.60
3.50
3.40
3.30
2.60
2.50
2.40
2.30
3.10
3.00
2.90
2.80
2.70
2.60
2.10
2.00
1.90
1.80
1.70
1.60
3.690
3.588
3.485
3.383
2.665
2.563
2.460
2.358
3.178
3.075
2.973
2.870
2.768
2.665
2.153
2.050
1.948
1.845
1.743
1.640
V
V
SYMBOL
V
BATT
V
CC
CONDITIONS
T
A
= 0°C to +85°C
T
A
= -40°C to +85°C
T
A
= 0°C to +85°C
T
A
= -40°C to +85°C
MIN
1.0
1.2
1.0
1.2
2.5
TYP
MAX
5.5
5.5
5.5
5.5
7
UNITS
V
V
µA
I
CC
+ I
BATT
V
BATT
= 3.6V, V
CC
= 3.3V, no load (Note 2)
2
_______________________________________________________________________________________
Low-Power, Single-/Dual-Level Battery Monitors
with Hysteresis and Integrated µP Reset
ELECTRICAL CHARACTERISTICS (continued)
(V
BATT
= 1.2V to 5.5V, V
CC
= 1.2V to 5.5V, T
A
= -40°C to +85°C, unless otherwise specified. Typical values are at T
A
= +25°C.) (Note1)
PARAMETER
SYMBOL
CONDITIONS
MAX6441UT_ J, MAX6442UT_ J
MAX6441UT_ I, MAX6442UT_ I
MAX6441UT_ H, MAX6442UT_ H
HTH- Threshold
HTH-
MAX6441UT_ G, MAX6442UT_ G
MAX6441UT_ T, MAX6442UT_ T
MAX6441UT_ S, MAX6442UT_ S
MAX6441UT_ R, MAX6442UT_ R
MAX6441UT_ Q, MAX6442UT_ Q
MAX6441UT_ J, MAX6442UT_ J
MAX6441UT_ I, MAX6442UT_ I
MAX6441UT_ H, MAX6442UT_ H
HTH+ Threshold
HTH+
MAX6441UT_ G, MAX6442UT_ G
MAX6441UT_ T, MAX6442UT_ T
MAX6441UT_ S, MAX6442UT_ S
MAX6441UT_ R, MAX6442UT_ R
MAX6441UT_ Q, MAX6442UT_ Q
MAX6441UTF, MAX6442UTF
MAX6441UTE, MAX6442UTE
MAX6441UTD, MAX6442UTD
MAX6441UTC, MAX6442UTC
MAX6441UTB, MAX6442UTB
LTH- Threshold
LTH-
MAX6441UTA, MAX6442UTA
MAX6441UTP, MAX6442UTP
MAX6441UTO, MAX6442UTO
MAX6441UTN, MAX6442UTN
MAX6441UTM, MAX6442UTM
MAX6441UTL, MAX6442UTL
MAX6441UTK, MAX6442UTK
MAX6441UTF, MAX6442UTF
MAX6441UTE, MAX6442UTE
MAX6441UTD, MAX6442UTD
MAX6441UTC, MAX6442UTC
MAX6441UTB, MAX6442UTB
LTH+ Threshold
LTH+
MAX6441UTA, MAX6442UTA
MAX6441UTP, MAX6442UTP
MAX6441UTO, MAX6442UTO
MAX6441UTN, MAX6442UTN
MAX6441UTM, MAX6442UTM
MAX6441UTL, MAX6442UTL
MAX6441UTK, MAX6442UTK
MIN
3.510
3.413
3.315
3.218
2.535
2.438
2.340
2.243
3.686
3.583
3.481
3.378
2.662
2.559
2.457
2.355
3.023
2.925
2.828
2.730
2.633
2.535
2.048
1.950
1.853
1.755
1.658
1.560
3.174
3.071
2.969
2.867
2.764
2.662
2.150
2.048
1.945
1.843
1.740
1.638
TYP
3.600
3.500
3.400
3.300
2.600
2.500
2.400
2.300
3.780
3.675
3.570
3.465
2.730
2.625
2.520
2.415
3.100
3.000
2.900
2.800
2.700
2.600
2.100
2.000
1.900
1.800
1.700
1.600
3.255
3.150
3.045
2.940
2.835
2.730
2.205
2.100
1.995
1.890
1.785
1.680
MAX
3.690
3.588
3.485
3.383
2.665
2.563
2.460
2.358
3.875
3.767
3.659
3.552
2.798
2.691
2.583
2.476
3.178
3.075
2.973
2.870
2.768
2.665
2.153
2.050
1.948
1.845
1.743
1.640
3.337
3.229
3.121
3.014
2.906
2.798
2.260
2.153
2.045
1.937
1.830
1.722
V
V
V
V
UNITS
MAX6439–MAX6442
_______________________________________________________________________________________
3
Low-Power, Single-/Dual-Level Battery Monitors
with Hysteresis and Integrated µP Reset
MAX6439–MAX6442
ELECTRICAL CHARACTERISTICS (continued)
(V
BATT
= 1.2V to 5.5V, V
CC
= 1.2V to 5.5V, T
A
= -40°C to +85°C, unless otherwise specified. Typical values are at T
A
= +25°C.) (Note1)
PARAMETER
LBO, LBOL, LBOH, LBOLH
Timeout Period
LBO, LBOL, LBOH, LBOLH
Delay Time
SYMBOL
t
LBOP
t
LBOD
CONDITIONS
V
BATT
rising above threshold
V
BATT
falling below threshold
(V
BATT
or V
CC
)
≥
1.2V, I
SINK
= 50µA,
asserted low
LBO, LBOL, LBOH, LBOLH
Output Low
(Open Drain)
(V
BATT
or V
CC
)
≥
1.6V, I
SINK
= 100µA,
asserted low
V
OL
(V
BATT
or V
CC
)
≥
2.7V, I
SINK
= 1.2mA,
asserted low
(V
BATT
or V
CC
)
≥
4.5V, I
SINK
= 3.2mA,
asserted low
LBO, LBOL, LBOH, LBOLH
Output Open-Drain Leakage
Current
I
LKG
Output deasserted
MAX64_ _ _ _ _ _ T
MAX64_ _ _ _ _ _ S
MAX64_ _ _ _ _ _ R
V
CC
Reset Threshold
V
TH
MAX64_ _ _ _ _ _ Z
MAX64_ _ _ _ _ _ Y
MAX64_ _ _ _ _ _ W
MAX64_ _ _ _ _ _ V
V
CC
Reset Hysteresis
V
CC
to
RESET
Delay
V
CC
to
RESET
Timeout Period
MR
Input Voltage
MR
Minimum Pulse Width
MR
Glitch Rejection
MR
to
RESET
Delay
MR
Reset Timeout Period
MR
Pullup Resistance
MR
Rising Debounce Period
t
DEB
t
MRP
MR
to V
CC
(Note 3)
150
750
150
t
RP
V
IL
V
IH
t
MPW
0.7 x V
CC
1
100
200
225
1500
225
300
2250
300
V
CC
falling at 10mV/µs from (V
TH
+ 100mV)
to (V
TH
- 100mV)
MAX64_ _ _ _ _ _ _ D3
MAX64_ _ _ _ _ _ _ D7
150
1200
3.000
2.850
2.550
2.250
2.125
1.620
1.530
3.075
2.925
2.625
2.313
2.188
1.665
1.575
0.3
50
225
1800
300
2400
0.3 x V
CC
MIN
150
TYP
225
100
0.3
0.3
V
0.3
0.3
MAX
300
UNITS
ms
µs
500
3.150
3.000
2.700
2.375
2.250
1.710
1.620
nA
V
%
µs
ms
V
µs
ns
ns
ms
Ω
ms
4
_______________________________________________________________________________________
Low-Power, Single-/Dual-Level Battery Monitors
with Hysteresis and Integrated µP Reset
MAX6439–MAX6442
ELECTRICAL CHARACTERISTICS (continued)
(V
BATT
= 1.2V to 5.5V, V
CC
= 1.2V to 5.5V, T
A
= -40°C to +85°C, unless otherwise specified. Typical values are at T
A
= +25°C.) (Note1)
PARAMETER
RESET
Output High
(Push-Pull)
SYMBOL
CONDITIONS
V
CC
≥
1.53V, I
SOURCE
= 100µA,
RESET
deasserted
V
OH
V
CC
≥
2.55V, I
SOURCE
= 500µA,
RESET
deasserted
V
CC
≥
1.0V, I
SINK
= 50µA,
RESET
asserted
RESET
Output Low
V
OL
V
CC
≥
1.2V, I
SINK
= 100µA,
RESET
asserted
V
CC
≥
2.12V, I
SINK
= 1.2mA,
RESET
asserted
RESET
deasserted
MIN
0.8 x V
CC
V
0.8 x V
CC
0.3
0.3
0.3
500
nA
V
TYP
MAX
UNITS
RESET
Output Leakage Current
(Open Drain)
Note 1:
Production testing done at T
A
= +25°C; limits over temperature guaranteed by design only.
Note 2:
The device is powered up by the highest voltage between V
BATT
and V
CC
.
Note 3:
MR
input ignores falling input pulses, which occur within the
MR
debounce period (t
DEB
) after a valid
MR
reset assertion.
This prevents invalid reset assertion due to switch bounce.
Typical Operating Characteristics
(V
BATT
= 1.2V to 5.5V, V
CC
= 1.2V to 5.5V, unless otherwise specified. Typical values are at T
A
= +25°C.)
SUPPLY CURRENT vs. TEMPERATURE
V
CC
= 3.3V, V
BATT
= 3.6V
MAX6439 toc01
NORMALIZED LBO TIMEOUT PERIOD
vs. TEMPERATURE
MAX6439 toc02
NORMALIZED RESET TIMEOUT PERIOD
vs. TEMPERATURE
NORMALIZED RESET TIMEOUT PERIOD
MAX6439 toc03
4
1.10
NORMALIZED LBO TIMEOUT PERIOD
1.015
1.010
1.005
1.000
0.995
0.990
0.985
0.980
SUPPLY CURRENT (µA)
3
TOTAL
2
I
BATT
1
I
CC
1.05
1.00
0.95
0
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
0.90
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
_______________________________________________________________________________________
5
