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General Description
The MAX4373/MAX4374/MAX4375 low-cost, micropower, high-side current-sense supervisors contain a highside current-sense amplifier, bandgap reference, and
comparator with latching output. They feature a voltage
output that eliminates the need for gain-setting resistors,
making them ideal for today’s notebook computers, cell
phones, and other systems where battery/DC current
monitoring is critical. High-side current monitoring is
especially useful in battery-powered systems since it
does not interfere with the ground path of the battery
charger. The 0 to +28V input common-mode range is
independent of the supply voltage, which ensures that
the current-sense feedback remains viable even when
connected to a battery pack in deep discharge.
The comparator output of the MAX4373/MAX4374/
MAX4375 is latched to provide a turn-off flag that
doesn’t oscillate. In addition, the MAX4374/MAX4375
contain a second comparator for use in window-detection functions. The MAX4373/MAX4374/MAX4375 are
available in three different gain versions (T = +20V/V,
F = +50V/V, H = +100V/V) and use an external sense
resistor to set the sensitivity of the input voltage to the
load current. These features offer a high level of integration, resulting in a simple and compact currentsense solution.
The MAX4373/MAX4374/MAX4375 operate from a single +2.7V to +28V supply and consume 50µA. They are
specified for the extended operating temperature range
(-40°C to +85°C) and are available in 8-pin and 10-pin
µMAX packages.
________________________Applications
Notebook Computers
Portable/Battery-Powered Systems
Smart Battery Packs/Chargers
Cell Phones
Power-Management Systems
General-System/Board-Level Current Monitoring
Precision Current Sources
Features
♦ Current-Sense Amplifier plus Internal Comparator
and Bandgap Reference
♦ 50µA Supply Current
♦ Single +2.7V to +28V Operating Supply
♦ 0.66% Full-Scale Accuracy
♦ Internal Bandgap Reference
♦ Latching Comparator Output
♦ Three Gain Versions Available (+20V/V, +50V/V,
+100V/V)
♦ Wide 0 to +28V Common-Mode Range,
Independent of Supply Voltage
MAX4373/MAX4374/MAX4375
Low-Cost, Micropower, High-Side Current-Sense
Amplifier + Comparator + Reference ICs
________________________________________________________________ Maxim Integrated Products 1
Typical Operating Circuit
19-1630; Rev 0; 3/00
Pin Configurations appear at end of data sheet.
8 SO
8 µMAX
PIN-
PACKAGE
TEMP. RANGE
-40°C to +85°C
-40°C to +85°CMAX4373TESA
MAX4373TEUA
PART
+20
+20
GAIN
(V/V)
8 µMAX-40°C to +85°CMAX4373FEUA +50
8 SO-40°C to +85°CMAX4373FESA +50
8 µMAX-40°C to +85°CMAX4373HEUA +100
8 SO-40°C to +85°CMAX4373HESA +100
Ordering Information continues at end of data sheet.
Ordering Information
+ V
V
CC
COUT
RESET
SENSE
R
SENSE
MAX4373
GND
VIN = 0 TO 28V
VCC = 2.7V TO 28V
0.1µF
V
= 5V
PULL-UP
C1
R3
I
LOAD
-
RS-RS+
OUT
CIN
LOAD/
BATTERY
R1
R2

MAX4373/MAX4374/MAX4375
Low-Cost, Micropower, High-Side Current-Sense
Amplifier + Comparator + Reference ICs
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VCC= +2.7V to +28V, V
RS+
= 0 to +28V, V
SENSE
= 0, V
RESET
= 0, R
LOAD
= 1MΩ, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical
values are at T
A
= +25°C.) (Note 1)
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.
VCC, RS+, RS- to GND ...........................................-0.3V to +30V
OUT to GND ................................................-0.3V to the lesser of
(V
CC
+ 0.3V) or +15V
CIN1, CIN2, RESET to GND ........................-0.3V to the lesser of
(V
CC
+ 0.3V) or +12V
Differential Input Voltage (V
RS
+ - VRS-)..............................±0.3V
COUT1, COUT2 to GND........................................-0.3V to +6.0V
Current into Any Pin..........................................................±10mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin µMAX (derate 4.1mW/°C above +70°C) .............330mW
8-Pin SO (derate 5.9mW/°C above +70°C)..................471mW
10-Pin µMAX (derate 5.6mW/°C above +70°C) ...........444mW
14-Pin SO (derate 8.3mW/°C above +70°C)................667mW
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
%
Total OUT Voltage Error
(Note 5)
V
SENSE
= 100mV
(Note 6)
V
SENSE
= 6.25mV, VCC= 12V, V
RS+
= 12V
(Note 7)
VCC= 12V,
V
RS+
= 0.1V
VCC= 28V, V
RS+
= 28V,
TA= T
MIN
to T
MAX
VCC= 12V, V
RS+
= 12V,
TA= T
MIN
to T
MAX
%
8.5 65I
OUT
= 100µA
I
OUT
= 10µA
±7.5
±0.55 ±7.5
±5.0
±5.0
PARAMETER SYMBOL MIN TYP MAX UNITS
-25 2.0
Input Bias Current
I
RS+
0 2.5
µA
Leakage Current I
RS+, IRS-
±0.015 ±0.5 µA
Supply Current I
CC
50 100 µA
I
RS-
04
-50 4
Full-Scale Sense Voltage
(Note 4)
V
SENSE
150 170
mV
100 120
Common-Mode Input Range
(Note 3)
Operating Voltage Range
(Note 2)
V
CC
2.7 28 V
V
CMR
028V
Common-Mode Rejection CMR 85 dB
OUT Voltage Low V
OUT
2.5
mV
OUT Voltage High
V
CC -
V
OH
0.25 V
CONDITIONS
V
RS+
≤ 2V
VCC= 2.7V
V
RS+
> 2V
V
CC
= 0
V
RS+
> 2V, V
SENSE
= 5mV
V
RS+
> 2V
V
RS+
≤ 2V
VCC= 2.7V, I
OUT
= -500µA
Gain = +20V/V, +50V/V
Gain = +100V/V
V
RS+
> 2V
Full-Scale Accuracy
(Note 5)
V
SENSE
= 100mV, VCC= 12V, V
RS+
= 12V,
TA= +25°C
±0.66 ±5.5

MAX4373/MAX4374/MAX4375
Low-Cost, Micropower, High-Side Current-Sense
Amplifier + Comparator + Reference ICs
_______________________________________________________________________________________ 3
V
SENSE
=
20mV to 150mV;
V
CC
= 12V; V
RS+
= 12V;
Gain = 20, 50
MAX437_T
V
RS+
= 12V,
VCC= 12V,
C
LOAD
= 10pF
V
SENSE
= 100mV, C
LOAD
= 10pF,
V
CC
= 12V, V
RS+
= 12V
Gain = +20V/V,
V
CC
= 12V,
V
RS+
= 12V,
C
LOAD
= 10pF
No sustained oscillations
V
SENSE
= 100mV
V
OUT
= 2V, V
RS+
> 2V
CONDITIONS
%
±0.64 ±5.2
∆A
V
Gain Accuracy
V/V
+20
A
V
kHz
200
BW-3dB Bandwidth
Gain
mV580 600 618Comparator Threshold
0.5
µs
20
OUT Settling Time to 1% of
Final Value
pF1000Capacitive Load Stability
Ω1.5R
OUT
OUT Output Resistance
72 87
UNITSMIN TYP MAXSYMBOLPARAMETER
120
110
50
V
SENSE
= 100mV,
Gain = +20V/V
V
SENSE
= 100mV,
Gain = +50V/V
V
SENSE
= 100mV,
Gain = +100V/V
V
SENSE
= 6.25mV
MAX437_H
MAX437_F
+100
+50
TA= +25°C
TA= -40°C to +85°C ±7.2
V
SENSE
= 6.25mV to
100mV
V
SENSE
= 100mV to
6.25mV
20
PSR
Power-Up Time to 1% of Final
Value
Power-Supply Rejection
ms
dB
VCC= 12V, V
RS+
= 12V, C
LOAD
= 10pF
Saturation Recovery Time
(Note 8)
ms0.1
mV-9Comparator Hysteresis
nA±2.2 ±15I
B
Input Bias Current
CL= 10pF, RL= 10kΩ pull-up to 5V,
5mV of overdrive
µs4Propagation Delay
I
SINK
= 1mA V0.6V
OL
Output Low Voltage
V
SENSE
=
20mV to 100mV,
V
CC
= 12V, V
RS+
= 12V,
Gain = 100
TA= +25°C
TA= -40°C to +85°C ±7.2
±0.62 ±5.0
COMPARATOR (Note 9)
ELECTRICAL CHARACTERISTICS (continued)
(VCC= +2.7V to +28V, V
RS+
= 0 to +28V, V
SENSE
= 0, V
RESET
= 0, R
LOAD
= 1MΩ, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical
values are at T
A
= +25°C.) (Note 1)

0
20
10
40
30
50
60
010155 202530
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX4373 toc01
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (µA)
MAX4373
MAX4374/MAX4375
V
SENSE
= 5mV
44
45
46
47
48
49
50
51
52
0105 15202530
SUPPLY CURRENT
vs. COMMON-MODE VOLTAGE
MAX4373 toc02
COMMON-MODE VOLTAGE (V)
SUPPLY CURRENT (µA)
MAX4374/MAX4375
MAX4373
V
SENSE
= 5mV
-2.0
-0.5
-1.0
-1.5
0
0.5
1.5
1.0
2.0
2684 10121416182022242628
TOTAL OUTPUT ERROR
vs. SUPPLY VOLTAGE
MAX4373 toc03
SUPPLY VOLTAGE (V)
OUTPUT ERROR (%)
AV = +100V/V
AV = +20V/V
AV = +50V/V
Typical Operating Characteristics
(V
RS+
= +12V, V
CC
= +12V, R
LOAD
= 1MΩ, V
RESET
= 0, V
SENSE
= 100mV, V
PULL-UP
= +5V, R
PULL-UP
= 10kΩ, TA= +25°C, unless
otherwise noted.)
MAX4373/MAX4374/MAX4375
Low-Cost, Micropower, High-Side Current-Sense
Amplifier + Comparator + Reference ICs
4 _______________________________________________________________________________________
Note 1: All devices are 100% production tested at TA= +25°C. All temperature limits are guaranteed by design.
Note 2: Guaranteed by PSR test.
Note 3: Guaranteed by OUT Voltage Error test.
Note 4: Guaranteed by Gain Accuracy test. Output voltage is internally clamped not to exceed 12V.
Note 5: Total OUT Voltage Error and Full-Scale Accuracy are the sum of gain and offset voltage errors.
Note 6: Measured at I
OUT
= -500µA (R
LOAD
= 4kΩ for gain of +20V/V, R
LOAD
= 10kΩ for gain of +50V/V, R
LOAD
= 20kΩ for gain of
+100V/V).
Note 7: +6.25mV = 1/16 of +100mV full-scale voltage.
Note 8: The device will not experience phase reversal when overdriven.
Note 9: All comparator tests are done with V
RS+
= +12V.
Note 10: V
PULL-UP
is defined as an externally applied voltage through a resistor to pull up the comparator output.
ELECTRICAL CHARACTERISTICS (continued)
(VCC= +2.7V to +28V, V
RS+
= 0 to +28V, V
SENSE
= 0, V
RESET
= 0, R
LOAD
= 1MΩ, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical
values are at T
A
= +25°C.) (Note 1)
VCC= 28V, V
PULL-UP
= 5V (Note 10)
CONDITIONS
µA1Output High Leakage Current
UNITSINTYP MAXSYMBOLPARAMETER
V2.0V
IH
RESET Input High Voltage
V0.8V
IL
RESET Input Low Voltage
V
IL
= 0, VIH= 5.5V, VCC= 28V µA-0.5 0.5IIL, I
IH
Logic Input Current
µs3t
RPD
RESET Propagation Delay
µs1.5t
RPW
Minimum RESET Pulse Width