For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
General Description
The MAX4372 low-cost, precision, high-side current-
sense amplifier is available in a tiny, space-saving
SOT23-5-pin package. Offered in three gain versions
(T = 20V/V, F = 50V/V, and H = 100V/V), this device
operates from a single 2.7V to 28V supply and con-
sumes only 30µA. It features a voltage output that elimi-
nates the need for gain-setting resistors and is 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 bat-
tery-powered systems since it does not interfere with
the ground path of the battery charger. The input com-
mon-mode range of 0 to 28V is independent of the sup-
ply voltage and ensures that the current-sense
feedback remains viable even when connected to a
2-cell battery pack in deep discharge.
The user can set the full-scale current reading by
choosing the device (T, F, or H) with the desired volt-
age gain and selecting the appropriate external sense
resistor. This capability offers a high level of integration
and flexibility, resulting in a simple and compact cur-
rent-sense solution. For higher bandwidth applications,
refer to the MAX4173T/F/H data sheet.
Applications
Power-Management Systems
General-System/Board-Level Current Monitoring
Notebook Computers
Portable/Battery-Powered Systems
Smart-Battery Packs/Chargers
Cell Phones
Precision-Current Sources
Features
oLow-Cost, Compact Current-Sense Solution
o30µA Supply Current
o2.7V to 28V Operating Supply
o0.18% Full-Scale Accuracy
o0.3mV Input Offset Voltage
oLow 1.5ΩOutput Impedance
oThree Gain Versions Available
20V/V (MAX4372T)
50V/V (MAX4372F)
100V/V (MAX4372H)
oHigh Accuracy +2V to +28V Common-Mode
Range, Functional Down to 0V, Independent of
Supply Voltage
oAvailable in a Space-Saving 5-Pin SOT23 Package
and 3 x 2 UCSP™ (1mm x 1.5mm) Package
MAX4372T/F/H
Low-Cost, UCSP/SOT23, Micropower, High-Side
Current-Sense Amplifier with Voltage Output
________________________________________________________________
Maxim Integrated Products
1
RS+
15RS-
MAX4372T/F/H
SOT23-5
UCSP
TOP VIEW TOP VIEW
(BUMPS ON BOTTOM)
2
34
OUT
OUT
VCC
VCC
GND
GND
231
A
B
MAX4372T/F/H
RS+ RS-
19-1548; Rev 4; 7/09
PART
MAX4372TEUK-T
MAX4372TESA -40°C to +85°C
-40°C to +85°C
TEMP RANGE PIN-PACKAGE
5 SOT23-5
8 SO
Pin Configurations
Ordering Information
TOP
MARK
ADIU
—
RS-
OUT
A/D
CONVERTER
VCC
VCC
GND
RS+
RSENSE VSENSE
ILOAD
VIN
0 TO 28V
+2.7V TO +28V
0.1μF
MAX4372T/F/H
LOAD/
BATTERY
Typical Operating Circuit
Note: Gain values are as follows: 20V/V for the T version, 50V/V
for the F version, and 100V/V for the H version.
Ordering Information continued at end of datasheet.
Pin Configurations continued at end of datasheet. UCSP is a trademark of Maxim Integrated Products, Inc.
MAX4372TEBT-T -40°C to +85°C 3 x 2 UCSP ACX
PART
MAX4372TEUK-T
MAX4372TESA -40°C to +85°C
-40°C to +85°C
TEMP RANGE PIN-PACKAGE
5 SOT23-5
8 SO
Ordering Information
TOP
MARK
ADIU
—
MAX4372TEBT-T -40°C to +85°C 3 x 2 UCSP ACX
MAX4372T/F/H
Low-Cost, UCSP/SOT23, Micropower, High-Side
Current-Sense Amplifier with Voltage Output
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VRS+ = 0 to 28V, VCC = 2.7V to 28V, VSENSE = 0, RLOAD = 1MΩ, TA = TMIN to TMAX, unless otherwise noted. Typical values are at
TA= +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 +15V
Differential Input Voltage (VRS+ - VRS-) ..............................±0.3V
Current into Any Pin..........................................................±10mA
Continuous Power Dissipation (TA= +70°C)
5-Pin SOT23 (derate 7.1mW/°C above +70°C).............571mW
8-Pin SO (derate 5.88mW/°C above +70°C).................471mW
3 x 2 UCSP (derate 3.4mW/°C above +70°C) ...........273.2mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s). ................................+300°C
Bump Temperature (soldering)
Infrared (15s) ................................................................+200°C
Vapor Phase (20s) ........................................................+215°C
VCC = 2.7V, IOUT = -500µA
VCC = 2.7V
VRS+ ≤2V
VRS+ > 2V
VRS+ ≤2V
VRS+ > 2V
VRS+ > 2V
VRS+ > 2V, VSENSE = 5mV
Gain = 100V/V
VCC = 0
Gain = 20V/V or 50V/V
CONDITIONS
V0.1 0.25VCC - VOH
OUT High Voltage
965
OUT Low Voltage mV
2.6
mV
100
VSENSE
150
Full-Scale Sense Voltage
(Note 4)
V028VCMR
Common-Mode Input Range
(Note 3)
V2.7 28VCC
Operating Voltage Range
(Note 2)
µA
-50 2
IRS-
Input Bias Current 02
-25 2
IRS+
01
dB85CMRCommon-Mode Rejection
µA30 60ICC
Supply Current
µA0.05 1.2IRS+, IRS-
Leakage Current
UNITSMIN TYP MAXSYMBOLPARAMETER
IOUT = 10µA
IOUT = 100µA
0.3 ±0.8
VSENSE = 100mV, VCC = 12V,
VRS+ = 12V (Note 7) ±6
VSENSE = 100mV, VCC = 28V,
VRS+ = 28V (Note 7) ±0.15 ±7
VSENSE = 100mV, VCC = 12V,
VRS+ = 0.1V (Note 7) ±1 ±28
VSENSE = 6.25mV, VCC = 12V,
VRS+ = 12V (Note 8)
%
±0.15
Total OUT Voltage Error
(Note 6)
VSENSE = 100mV, VCC = 12V,
VRS+ = 12V, TA= +25°C (Note 7) %±0.18 ±3
Full-Scale Accuracy
(Note 5)
TA= +25°C
VCC = VRS+ = 12V 0.3 ±1.3
±1.1
TA= TMIN to TMAX
VCC = VRS+ = 12V
mV
±1.9
VOS
Input Offset Voltage
(Note 5)
MAX4372_ESA
MAX4372_EUK, _EBT
MAX4372_ESA
MAX4372_EUK, _EBT
MAX4372T/F/H
Low-Cost, UCSP/SOT23, Micropower, High-Side
Current-Sense Amplifier with Voltage Output
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VRS+ = 0 to 28V, VCC = 2.7V to 28V, VSENSE = 0, RLOAD = 1MΩ, TA = TMIN to TMAX, unless otherwise noted. Typical values are at
TA= +25°C.) (Note 1)
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: Output voltage is internally clamped not to exceed 12V.
Note 5: VOS is extrapolated from the gain accuracy tests.
Note 6: Total OUT voltage error is the sum of gain and offset voltage errors.
Note 7: Measured at IOUT = -500µA (RLOAD = 4kΩfor gain = 20V/V, RLOAD = 10kΩfor gain = 50V/V, RLOAD = 20kΩfor gain =
100V/V).
Note 8: 6.25mV = 1/16 of 100mV full-scale voltage (C/16).
Note 9: The device will not reverse phase when overdriven.
VRS+= 12V,
VCC = 12V,
CLOAD = 10pF
CONDITIONS
MAX4372T 20
VSENSE= 20mV,
gain = 20V/V
kHz
50
BW
275
UNITSMIN TYP MAXSYMBOLPARAMETER
VSENSE = 20mV,
gain = 50V/V 200
VSENSE = 20mV,
gain = 100V/V 110
-3dB Bandwidth
MAX4372F
MAX4372H
V/V
100
Gain 50
No sustained oscillations
VSENSE = 100mV Ω1.5ROUT
OUT Output Resistance
pF1000Capacitive-Load Stability
VSENSE = 20mV
to 100mV %
±5.5
Gain Accuracy
VOUT = 2V, VRS+ > 2V
VCC = 12V, VRS+ = 12V, CLOAD = 10pF ms0.1
Saturation Recovery Time
(Note 9)
VCC = 12V, VRS+ = 12V,
VSENSE = 100mV, CLOAD = 10pF ms0.5
Power-Up Time to 1% of
Final Value
dB75 85PSRPower-Supply Rejection
VSENSE = 6.25mV
±0.25 ±2.5TA= +25°C
TA= -40°C to +85°C
VSENSE = 6.25mV to
100mV 20
VSENSE = 100mV to
6.25mV
Gain = 20V/V,
VCC = 12V,
VRS+ = 12V,
CLOAD = 10pF
µs
20
OUT Settling Time to 1% of
Final Value
MAX4372T/F/H
Low-Cost, UCSP/SOT23, Micropower, High-Side
Current-Sense Amplifier with Voltage Output
4 _______________________________________________________________________________________
Typical Operating Characteristics
(VCC = 12V, VRS+ = 12V, VSENSE = 100mV, TA = +25°C, unless otherwise noted.)
25.0
27.5
30.0
32.5
35.0
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX4372 toc01
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (μA)
012164 8 20 24 28
AV = +100V/V
AV = +50V/V
AV = +20V/V
VSENSE = 5mV
0
5
10
15
20
25
30
35
40
-40 10 60-15 35 85
SUPPLY CURRENT vs. TEMPERATURE
MAX4372T toc02
TEMPERATURE (°C)
SUPPLY CURRENT (μA)
VSENSE = 5mV
28.0
29.0
28.5
30.0
29.5
31.5
31.0
30.5
32.0
SUPPLY CURRENT
vs. COMMON-MODE VOLTAGE
MAX4372 toc03
COMMON-MODE VOLTAGE (V)
SUPPLY CURRENT (μA)
012164 8 20 24 28
AV = +100V/V
AV = +50V/V
AV = +20V/V
VSENSE = 5mV
-1.2
-0.8
-1.0
-0.2
-0.4
-0.6
0.4
0.2
0
0.6
0105 15202530
TOTAL OUTPUT ERROR
vs. SUPPLY VOLTAGE
MAX4372 toc04
SUPPLY VOLTAGE (V)
OUTPUT ERROR (%)
G = +100V/V
G = +50V/V
G = +20V/V
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
0105 15202530
TOTAL OUTPUT ERROR
vs. COMMON-MODE VOLTAGE
MAX4372T toc07
COMMON-MODE VOLTAGE (V)
OUTPUT ERROR (%)
G = +100V/V
G = +50V/V
G = +20V/V
-1.0
-0.5
0.5
0
1.0
1.5
010050 150 200 250 300
TOTAL OUTPUT ERROR vs. VSENSE
MAX4372T toc05
VSENSE (mV)
OUTPUT ERROR (%)
AV = +100V/V
AV = +20V/V
AV = +50V/V
-45
-90 100 100k10k1k
POWER-SUPPLY REJECTION
vs. FREQUENCY
-75
-85
-55
-65
-40
-70
-80
-50
-60
MAX4372T toc06
FREQUENCY (Hz)
PSR (dB)
-1.0
-0.9
-0.8
-0.7
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
0
GAIN ACCURACY vs. TEMPERATURE
MAX4372T toc08
TEMPERATURE (°C)
GAIN ACCURACY (%)
-40 10 60-15 35 85
AV = +20V/V
AV = +50V/V
AV = +100V/V
-1.0
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1.0
-40 10 60-15 35 85
TOTAL OUTPUT ERROR vs. TEMPERATURE
MAX4372T toc09
TEMPERATURE (°C)
TOTAL OUTPUT ERROR (%)
AV = +50V/V
AV = +100V/V
AV = +20V/V
VOUT
VSENSE
600mV
200mV
30mV
10mV
MAX4372T
SMALL-SIGNAL TRANSIENT RESPONSE
MAX4372T toc10
20μs/div
VOUT
VSENSE
1.5V
0.5V
30mV
10mV
MAX4372F
SMALL-SIGNAL TRANSIENT RESPONSE
MAX4372T toc11
20μs/div
VOUT
VSENSE
3V
1V
30mV
10mV
MAX4372H
SMALL-SIGNAL TRANSIENT RESPONSE
MAX4372T toc12
20μs/div
VOUT
VSENSE
1V
3V
50mV
150mV
MAX4372T
LARGE-SIGNAL TRANSIENT RESPONSE
MAX4372T toc13
20μs/div
VOUT
VSENSE
2.5V
7.5V
50mV
150mV
MAX4372F
LARGE-SIGNAL TRANSIENT RESPONSE
20μs/div
MAX4372T toc14
3
-8 1k 100k10k 1M
SMALL-SIGNAL GAIN vs. FREQUENCY
-7
MAX4372T toc16
FREQUENCY (Hz)
GAIN (dB)
-6
-5
-4
-3
-2
-1
0
1
2
G = 50V/V
G = 20V/V
G = 100V/V
VSENSE = 20mV
VOUT
VSENSE
0
10V
0
100mV
MAX4372H
LARGE-SIGNAL TRANSIENT RESPONSE
20μs/div
MAX4372T toc15
MAX4372T/F/H
Low-Cost, UCSP/SOT23, Micropower, High-Side
Current-Sense Amplifier with Voltage Output
_______________________________________________________________________________________
5
Typical Operating Characteristics (continued)
(VCC = 12V, VRS+ = 12V, VSENSE = 100mV, TA = +25°C, unless otherwise noted.)
_______________Detailed Description
The MAX4372 high-side current-sense amplifier fea-
tures a 0 to 28V input common-mode range that is inde-
pendent of supply voltage. This feature allows the
monitoring of current flow out of a battery in deep dis-
charge, and also enables high-side current sensing at
voltages far in excess of the supply voltage (VCC).
Current flows through the sense resistor, generating a
sense voltage (Figure 1). Since A1’s inverting input is
high impedance, the voltage on the negative terminal
equals VIN - VSENSE. A1 forces its positive terminal to
match its negative terminal; therefore, the voltage
across RG1 (VIN - V1-) equals VSENSE. This creates a
current to flow through RG1 equal to VSENSE / RG1. The
transistor and current mirror amplify the current by a
factor of β. This makes the current flowing out of the
current mirror equal to:
IM= βVSENSE / RG1
A2’s positive terminal presents high impedance, so this
current flows through RGD, with the following result:
V2+ = RGD β··VSENSE / RG1
R1 and R2 set the closed-loop gain for A2, which ampli-
fies V2+, yielding:
VOUT = RGD ··β··VSENSE / RG1 (1 + R2 / R1)
The gain of the device equals:
VOUT = RGD ··β(1 + R2 / R1) / RG1
VSENSE
__________Applications Information
Recommended Component Values
The MAX4372 operates over a wide variety of current
ranges with different sense resistors. Table 1 lists com-
mon resistor values for typical operation of the
MAX4372.
Choosing RSENSE
Given the gain and maximum load current, select RSENSE
such that VOUT does not exceed VCC - 0.25V or 10V. To
measure lower currents more accurately, use a high
value for RSENSE. A higher value develops a higher sense
voltage, which overcomes offset voltage errors of the
internal current amplifier.
In applications monitoring very high current, ensure
RSENSE is able to dissipate its own I2R losses. If the
resistor’s rated power dissipation is exceeded, its value
may drift or it may fail altogether, causing a differential
voltage across the terminals in excess of the absolute
maximum ratings.
MAX4372T/F/H
Low-Cost, UCSP/SOT23, Micropower, High-Side
Current-Sense Amplifier with Voltage Output
6 _______________________________________________________________________________________
MAX4372T/F/H
GND
TO
LOAD
VIN
0 TO 28V
2.7V
TO
28V
R1
RGD
RG2
100kΩ
RS+
RS-
RG1
100kΩ
R2
OUT
V2+
V1+
V1-
V2-
VCC RSENSE
ILOAD
IM
VSENSE
CURRENT
MIRROR
A1
A2
Pin Description
1 3 Ground
2 4 Output Voltage. VOUT is proportional to the magnitude of VSENSE
(VRS+ - VRS-).
A2
A3
SO FUNCTION
SOT23 UCSP
3 1 Supply Voltage. Use at least a 0.1µF capacitor to decouple VCC from fast
transients.
4 8 Power Connection to the External Sense Resistor
A1
B1
5 6 Load-Side Connection to the External Sense Resistor
—2, 5, 7 No Connection. Not internally connected.
B3
—
Figure 1. Functional Diagram
GND
OUT
NAME
VCC
RS+
RS-
N.C.
PIN
MAX4372T/F/H
Using a PC Board Trace as RSENSE
If the cost of RSENSE is an issue and accuracy is not
critical, use the alternative solution shown in Figure 2.
This solution uses copper PC board traces to create a
sense resistor. The resistivity of a 0.1-inch-wide trace of
2-ounce copper is about 30mΩ/ft. The resistance tem-
perature coefficient of copper is fairly high (approxi-
mately 0.4%/°C), so systems that experience a wide
temperature variance must compensate for this effect.
In addition, self-heating will introduce a nonlinearity
error. Do not exceed the maximum power dissipation of
the copper trace.
For example, the MAX4372T (with a maximum load cur-
rent of 10A and an RSENSE of 5mΩ) creates a full-scale
VSENSE of 50mV that yields a maximum VOUT of 1V.
RSENSE, in this case, requires about 2 inches of 0.1-
inch-wide copper trace.
UCSP Applications Information
For the latest application details on UCSP construction,
dimensions, tape carrier information, printed circuit
board techniques, bump-pad layout, and recommend-
ed reflow temperature profile, as well as the latest infor-
mation on reliability testing results, go to the Maxim's
website at www.maxim-ic.com/ucsp to find the
Application Note:
UCSP—A Wafer-Level Chip-Scale
Package.
Table 1. Recommended Component Values
FULL-SCALE LOAD
CURRENT,
ILOAD (A)
GAIN
(V/V)
CURRENT-SENSE
RESISTOR,
RSENSE (mΩ)
2.0
FULL-SCALE OUTPUT
VOLTAGE (FULL-SCALE
VSENSE = 100mV),
VOUT (V)
5.0
10.0
0.1 1000
20
100
50
2.0
100
50 5.0
10.0
1100
20
2.0
100
50 5.0
2.0
100
50 5.0
10.0
520
20
10.0
10 10
20
0.1in COPPER 0.3in COPPER0.3in COPPER
INPUT LOAD/BATTERY
VCC
VSENSE
RSENSE
GND
2.7V TO 28V
RS+
RS- OUT
MAX4372T/F/H
Figure 2. Connections Showing Use of PC Board
Low-Cost, UCSP/SOT23, Micropower, High-Side
Current-Sense Amplifier with Voltage Output
_______________________________________________________________________________________ 7
MAX4372T/F/H
Low-Cost, UCSP/SOT23, Micropower, High-Side
Current-Sense Amplifier with Voltage Output
8 _______________________________________________________________________________________
RS-
N.C.OUT
1
2
8
7
RS+
N.C.N.C.
GND
VCC
SO
3
4
6
5
MAX4372T/F/H
Chip Information
TRANSISTOR COUNT: 225
PROCESS: BiCMOS
PART
MAX4372FEUK-T -40°C to +85°C
TEMP RANGE PIN-PACKAGE
5 SOT23-5
TOP
MARK
ADIV
MAX4372FESA
MAX4372HEUK-T
MAX4372HESA -40°C to +85°C
-40°C to +85°C
-40°C to +85°C 8 SO
5 SOT23-5
8 SO
MAX4372FEBT-T -40°C to +85°C 3 x 2 UCSP
—
ADIW
—
ACY
MAX4372HEBT-T -40°C to +85°C 3 x 2 UCSP ACZ
Pin Configurations (continued)Ordering Information (continued)
6L, UCSP.EPS
G11
21-0097
PACKAGE OUTLINE, 3x2 UCSP
Package Information
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the
package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the
package regardless of RoHS status.
Note: MAX4372_EBT uses package code B6-2.
MAX4372T/F/H
Low-Cost, UCSP/SOT23, Micropower, High-Side
Current-Sense Amplifier with Voltage Output
_______________________________________________________________________________________ 9
SOICN .EPS
PACKAGE OUTLINE, .150" SOIC
1
1
21-0041 B
REV.DOCUMENT CONTROL NO.APPROVAL
PROPRIETARY INFORMATION
TITLE:
TOP VIEW
FRONT VIEW
MAX
0.010
0.069
0.019
0.157
0.010
INCHES
0.150
0.007
E
C
DIM
0.014
0.004
B
A1
MIN
0.053A
0.19
3.80 4.00
0.25
MILLIMETERS
0.10
0.35
1.35
MIN
0.49
0.25
MAX
1.75
0.050
0.016L0.40 1.27
0.3940.386D
D
MINDIM
D
INCHES
MAX
9.80 10.00
MILLIMETERS
MIN MAX
16 AC
0.337 0.344 AB8.758.55 14
0.189 0.197 AA5.004.80 8
N MS012
N
SIDE VIEW
H 0.2440.228 5.80 6.20
e 0.050 BSC 1.27 BSC
C
HE
eBA1
A
D
0∞-8∞
L
1
VARIATIONS:
Package Information (continued)
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the
package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the
package regardless of RoHS status.
MAX4372T/F/H
Low-Cost, UCSP/SOT23, Micropower, High-Side
Current-Sense Amplifier with Voltage Output
10 ______________________________________________________________________________________
SOT-23 5L .EPS
Package Information (continued)
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the
package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the
package regardless of RoHS status.
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________
11
© 2009 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
Low-Cost, UCSP/SOT23, Micropower, High-Side
Current-Sense Amplifier with Voltage Output
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
4 7/09 Updated feature in accordance with actual performance of the product 1
