19-1548; Rev 3; 12/05
Low-Cost, UCSP/SOT23, Micropower, High-Side
Current-Sense Amplifier with Voltage Output
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.
♦
30µA Supply Current
♦
2.7V to 28V Operating Supply
♦
0.18% Full-Scale Accuracy
♦
0.3mV Input Offset Voltage
♦
Low 1.5Ω Output Impedance
♦
Three Gain Versions Available
20V/V (MAX4372T)
50V/V (MAX4372F)
100V/V (MAX4372H)
♦
Wide 0 to 28V Common-Mode Range,
Independent of Supply Voltage
♦
Available in a Space-Saving 5-Pin SOT23 Package
and 3 x 2 UCSP™ (1mm x 1.5mm) Package
Features
♦
Low-Cost, Compact Current-Sense Solution
MAX4372T/F/H
Ordering Information
PART
TEMP RANGE PIN-PACKAGE
TOP
MARK
ADIU
—
ACX
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
MAX4372TEUK-T
-40°C to +85°C 5 SOT23-5
MAX4372TESA
MAX4372TEBT-T
-40°C to +85°C 8 SO
-40°C to +85°C 3 x 2 UCSP
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.
Typical Operating Circuit
Pin Configurations
I
LOAD
GND
RS-
TOP VIEW
TOP VIEW
(BUMPS ON BOTTOM)
1
2
GND
3
5
RS-
A
V
CC
OUT
MAX4372T/F/H
A/D
CONVERTER
OUT
R
SENSE
V
SENSE
GND
1
LOAD/
BATTERY
OUT
2
MAX4372T/F/H
MAX4372T/F/H
B
RS+
RS-
V
CC
+2.7V TO +28V
0.1µF
V
CC
V
CC
RS+
V
IN
0 TO 28V
3
4
RS+
UCSP
SOT23-5
Pin Configurations continued at end of datasheet.
UCSP is a trademark of Maxim Integrated Products, Inc.
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-Cost, UCSP/SOT23, Micropower, High-Side
Current-Sense Amplifier with Voltage Output
MAX4372T/F/H
ABSOLUTE MAXIMUM RATINGS
V
CC
, RS+, RS- to GND ...........................................-0.3V to +30V
OUT to GND ...........................................................-0.3V to +15V
Differential Input Voltage (V
RS+
- V
RS-
) ..............................±0.3V
Current into Any Pin..........................................................±10mA
Continuous Power Dissipation (T
A
= +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
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
RS+
= 0 to 28V, V
CC
= 2.7V to 28V, V
SENSE
= 0, R
LOAD
= 1MΩ, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at
T
A
= +25°C.) (Note 1)
PARAMETER
Operating Voltage Range
(Note 2)
Common-Mode Input Range
(Note 3)
Common-Mode Rejection
Supply Current
Leakage Current
SYMBOL
V
CC
V
CMR
CMR
I
CC
I
RS+
, I
RS-
I
RS+
Input Bias Current
I
RS-
Full-Scale Sense Voltage
(Note 4)
V
SENSE
V
RS+
> 2V
V
RS+
> 2V, V
SENSE
= 5mV
V
CC
= 0
V
RS+
> 2V
V
RS+
≤
2V
V
RS+
> 2V
V
RS+
≤
2V
Gain = 20V/V or 50V/V
Gain = 100V/V
T
A
= +25°C
V
CC
= V
RS+
= 12V
T
A
= T
MIN
to T
MAX
V
CC
= V
RS+
= 12V
MAX4372_ESA
MAX4372_EUK, _EBT
MAX4372_ESA
MAX4372_EUK, _EBT
±0.18
0
-25
0
-50
150
100
0.3
0.3
±0.8
±1.3
±1.1
±1.9
±3
±6
±0.15
±1
±0.15
2.6
9
0.1
65
0.25
mV
V
±7
%
±28
%
mV
CONDITIONS
MIN
2.7
0
85
30
0.05
60
1.2
1
2
2
2
mV
µA
TYP
MAX
28
28
UNITS
V
V
dB
µA
µA
Input Offset Voltage
(Note 5)
V
OS
Full-Scale Accuracy
(Note 5)
V
SENSE
= 100mV, V
CC
= 12V,
V
RS+
= 12V, T
A
= +25°C (Note 7)
V
SENSE
= 100mV, V
CC
= 12V,
V
RS+
= 12V (Note 7)
V
SENSE
= 100mV, V
CC
= 28V,
V
RS+
= 28V (Note 7)
V
SENSE
= 100mV, V
CC
= 12V,
V
RS+
= 0.1V (Note 7)
V
SENSE
= 6.25mV, V
CC
= 12V,
V
RS+
= 12V (Note 8)
Total OUT Voltage Error
(Note 6)
OUT Low Voltage
OUT High Voltage
2
V
CC
- V
OH
V
CC
= 2.7V
I
OUT
= 10µA
I
OUT
= 100µA
V
CC
= 2.7V, I
OUT
= -500µA
_______________________________________________________________________________________
Low-Cost, UCSP/SOT23, Micropower, High-Side
Current-Sense Amplifier with Voltage Output
ELECTRICAL CHARACTERISTICS (continued)
(V
RS+
= 0 to 28V, V
CC
= 2.7V to 28V, V
SENSE
= 0, R
LOAD
= 1MΩ, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at
T
A
= +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
V
SENSE
= 20mV,
gain = 20V/V
-3dB Bandwidth
BW
V
RS
+ = 12V,
V
CC
= 12V,
C
LOAD
= 10pF
V
SENSE
= 20mV,
gain = 50V/V
V
SENSE
= 20mV,
gain = 100V/V
V
SENSE
= 6.25mV
MAX4372T
Gain
MAX4372F
MAX4372H
Gain Accuracy
V
SENSE
= 20mV
to 100mV
Gain = 20V/V,
V
CC
= 12V,
V
RS+
= 12V,
C
LOAD
= 10pF
T
A
= +25°C
T
A
= -40°C to +85°C
V
SENSE
= 6.25mV to
100mV
V
SENSE
= 100mV to
6.25mV
20
µs
20
1000
1.5
75
85
0.5
0.1
pF
Ω
dB
ms
ms
MIN
TYP
275
200
110
50
20
50
100
±0.25
±2.5
±5.5
%
V/V
MAX
UNITS
MAX4372T/F/H
kHz
OUT Settling Time to 1% of
Final Value
Capacitive-Load Stability
OUT Output Resistance
Power-Supply Rejection
Power-Up Time to 1% of
Final Value
Saturation Recovery Time
(Note 9)
R
OUT
PSR
No sustained oscillations
V
SENSE
= 100mV
V
OUT
= 2V, V
RS+
> 2V
V
CC
= 12V, V
RS+
= 12V,
V
SENSE
= 100mV, C
LOAD
= 10pF
V
CC
= 12V, V
RS+
= 12V, C
LOAD
= 10pF
Note 1:
All devices are 100% production tested at T
A
= +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:
V
OS
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 I
OUT
= -500µA (R
LOAD
= 4kΩ for gain = 20V/V, R
LOAD
= 10kΩ for gain = 50V/V, R
LOAD
= 20kΩ for 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.
_______________________________________________________________________________________
3
Low-Cost, UCSP/SOT23, Micropower, High-Side
Current-Sense Amplifier with Voltage Output
MAX4372T/F/H
Typical Operating Characteristics
(V
CC
= 12V, V
RS+
= 12V, V
SENSE
= 100mV, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX4372 toc01
SUPPLY CURRENT vs. TEMPERATURE
MAX4372T toc02
SUPPLY CURRENT
vs. COMMON-MODE VOLTAGE
A
V
= +100V/V
31.5
SUPPLY CURRENT (µA)
31.0
30.5
30.0
29.5
A
V
= +20V/V
29.0
28.5
V
SENSE
= 5mV
0
4
8
12
16
20
24
28
A
V
= +50V/V
MAX4372 toc03
35.0
40
35
SUPPLY CURRENT (µA)
30
25
20
15
10
5
32.0
SUPPLY CURRENT (µA)
32.5
A
V
= +100V/V
30.0
A
V
= +50V/V
A
V
= +20V/V
27.5
V
SENSE
= 5mV
25.0
0
4
8
12
16
20
24
28
0
-40
V
SENSE
= 5mV
-15
10
35
60
85
28.0
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
COMMON-MODE VOLTAGE (V)
TOTAL OUTPUT ERROR
vs. SUPPLY VOLTAGE
MAX4372 toc04
TOTAL OUTPUT ERROR vs. V
SENSE
MAX4372T toc05
POWER-SUPPLY REJECTION
vs. FREQUENCY
-45
-50
-55
MAX4372T toc06
0.6
0.4
0.2
OUTPUT ERROR (%)
0
-0.2
-0.4
-0.6
-0.8
-1.0
-1.2
0
5
10
15
20
25
G = +50V/V
G = +20V/V
G = +100V/V
1.5
-40
1.0
OUTPUT ERROR (%)
A
V
= +100V/V
A
V
= +50V/V
PSR (dB)
0.5
-60
-65
-70
-75
0
A
V
= +20V/V
-0.5
-80
-85
30
-1.0
0
50
100
150
V
SENSE
(mV)
200
250
300
-90
100
1k
10k
100k
SUPPLY VOLTAGE (V)
FREQUENCY (Hz)
TOTAL OUTPUT ERROR
vs. COMMON-MODE VOLTAGE
MAX4372T toc07
GAIN ACCURACY vs. TEMPERATURE
-0.1
-0.2
GAIN ACCURACY (%)
-0.3
-0.4
-0.5
-0.6
-0.7
-0.8
-0.9
A
V
= +50V/V
A
V
= +100V/V
A
V
= +20V/V
MAX4372T toc08
TOTAL OUTPUT ERROR vs. TEMPERATURE
0.8
TOTAL OUTPUT ERROR (%)
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
A
V
= +20V/V
A
V
= +100V/V
A
V
= +50V/V
MAX4372T toc09
1.6
1.4
OUTPUT ERROR (%)
1.2
1.0
0.8
0.6
0.4
0.2
0
0
5
G = +20V/V
G = +50V/V
G = +100V/V
0
1.0
10
15
20
25
30
-1.0
-40
-15
10
35
TEMPERATURE (°C)
60
85
-40
-15
10
35
60
85
COMMON-MODE VOLTAGE (V)
TEMPERATURE (°C)
4
_______________________________________________________________________________________
Low-Cost, UCSP/SOT23, Micropower, High-Side
Current-Sense Amplifier with Voltage Output
MAX4372T/F/H
Typical Operating Characteristics (continued)
(V
CC
= 12V, V
RS+
= 12V, V
SENSE
= 100mV, T
A
= +25°C, unless otherwise noted.)
MAX4372T
SMALL-SIGNAL TRANSIENT RESPONSE
MAX4372T toc10
MAX4372F
SMALL-SIGNAL TRANSIENT RESPONSE
MAX4372T toc11
MAX4372H
SMALL-SIGNAL TRANSIENT RESPONSE
MAX4372T toc12
30mV
V
SENSE
10mV
V
SENSE
30mV
V
SENSE
30mV
10mV
10mV
600mV
V
OUT
200mV
V
OUT
1.5V
V
OUT
0.5V
3V
1V
20µs/div
20µs/div
20µs/div
MAX4372T
LARGE-SIGNAL TRANSIENT RESPONSE
MAX4372T toc13
MAX4372F
LARGE-SIGNAL TRANSIENT RESPONSE
MAX4372T toc14
V
SENSE
150mV
V
SENSE
150mV
50mV
3V
50mV
7.5V
V
OUT
1V
20µs/div
V
OUT
2.5V
20µs/div
MAX4372H
LARGE-SIGNAL TRANSIENT RESPONSE
MAX4372T toc15
SMALL-SIGNAL GAIN vs. FREQUENCY
2
MAX4372T toc16
3
100mV
1
0
GAIN (dB)
0
10V
-1
-2
-3
-4
-5
-6
0
-7
-8
1k
V
SENSE
= 20mV
10k
100k
G = 100V/V
V
SENSE
G = 50V/V
G = 20V/V
V
OUT
20µs/div
1M
FREQUENCY (Hz)
_______________________________________________________________________________________
5
