19-2423; Rev 3; 11/08
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
General Description
The MAX4069–MAX4072 low-cost, bidirectional, high-
side, current-sense amplifiers are ideal for monitoring
battery charge and discharge currents in notebooks,
cell phones, and other portable equipment. They fea-
ture up to 24V input common-mode voltage range, low
100µA supply current (which drops to only 10µA in
shutdown), and a total output error of less than 1.5%.
The wide 1.35V to 24V input common-mode range is
independent of the supply voltage, ensuring that the
current-sense feedback remains accurate even when
connected to a battery pack in deep discharge.
To achieve maximum flexibility, an external current-sense
resistor is used along with a Gain Select pin to choose
either 50V/V or 100V/V. A single output pin continuously
monitors the transition from charge to discharge and
avoids the need for a separate polarity output. The
MAX4070 contains an internal 2.5V reference. The
charging current is represented by an output voltage
from 2.5V to V
CC
, while discharge current is given from
2.5V to GND. The MAX4071 is similar, but with a refer-
ence voltage of 1.5V. The MAX4069 has an adjustable
reference voltage, set by two external resistors. The
MAX4072 has an input for an external reference.
The MAX4069/MAX4071/MAX4072 operate from a 2.7V to
24V single supply. The MAX4070 operates from a 3.6V to
24V single supply. All devices are specified over the
automotive operating temperature range, -40°C to
+125°C. The MAX4070/MAX4071/MAX4072 are available
in 8-pin µMAX and 8-pin thin QFN packages. The
MAX4069 is available in a 10-pin µMAX
®
package.
♦
Total Output Error Less than 1.5%
♦
Selectable Gain of 50V/V or 100V/V
♦
Wide 1.35V to 24V Common-Mode Range
Independent of Supply Voltage
♦
2.7V to 24V Single-Supply Operation
♦
Internal Precision Reference
Adjustable (MAX4069)
2.50V (MAX4070)
1.50V (MAX4071)
♦
Low 100µA Supply Current
♦
10µA Supply Current in Shutdown
♦
Available in Space-Saving Packages
8-Pin Thin QFN (MAX4070/MAX4071/MAX4072)
8-Pin
µMAX
(MAX4070/MAX4071MAX4072)
10-Pin
µMAX
(MAX4069)
Features
♦
Bidirectional, Compact, Current-Sense Solution
MAX4069–MAX4072
Ordering Information
PART
MAX4069AUB
MAX4070AUA
MAX4070ATA
MAX4071AUA
MAX4071ATA
MAX4072AUA
TEMP RANGE
PIN-PACKAGE
TOP
MARK
—
—
ABN
—
ABO
—
ABP
-40°C to +125°C 10 µMAX
-40°C to +125°C 8 µMAX
-40°C to +125°C 8 Thin QFN-EP*
-40°C to +125°C 8 µMAX
-40°C to +125°C 8 Thin QFN-EP*
-40°C to +125°C 8 µMAX
Applications
Notebook Fuel Gauging
Smart-Battery Packs/Chargers
Motor Control
Power-Management Systems
Cell-Phone Battery-Current Monitoring
MAX4072ATA
-40°C to +125°C 8 Thin QFN-EP*
*EP
= Exposed pad.
Typical Operating Circuit
FROM BATTERY
CHARGER
R
SENSE
V
BATT
= 1.35V TO 24V
RS-
RS+
LOAD
V
CC
= 3.6V TO 24V
V
CC
MAX4070
GSEL
OUT
TO ADC
µMAX is a registered trademark of Maxim Integrated Products, Inc.
Pin Configurations and Selector Guide appear at end of
data sheet.
SHDN
GND
REFOUT
2.5V
________________________________________________________________
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.
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
MAX4069–MAX4072
ABSOLUTE MAXIMUM RATINGS
V
CC
, RS+, RS- to GND ...........................................-0.3V to +26V
OUT to GND ....................-0.3V to Lesser of (V
CC
+ 0.3V) or 15V
Differential Input Voltage (V
RS
+ - V
RS
-) ..............................±0.3V
GSEL,
SHDN,
REFOUT, REFIN
and ADJ to GND.....................................-0.3V to (V
CC
+ 0.3V)
OUT Short-Circuit Duration to GND
or to Lesser of (V
CC
or 15V) ...................................Continuous
REFOUT Short Circuit to V
CC
or GND........................Continuous
Current into Any Pin ..........................................................±20mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin µMAX (derate 4.5 mW/°C above +70°C) ............362mW
8-Pin Thin QFN (derate 24.4mW/°C above +70°C) ...1951mW
10-Pin µMAX (derate 5.6 mW/°C above +70°C) .......444.4mW
Operating Temperature Range .........................-40°C to +125°C
Junction Temperature ......................................................+150°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
RS
+ = V
RS
- = V
CC
= 2.7V to 24V, V
SENSE
= V
RS
+ - V
RS
- = 0V, I
REFOUT
= 0, V
SHDN
= V
CC
, V
GSEL
= GND, V
REFIN
= 2.5V (MAX4072),
T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C and at V
CC
= V
RS
+ = 12V.) (Notes 1, 2)
PARAMETER
Operating Voltage Range
(Note 3)
Input-Referred Offset Voltage
(Note 5)
Common-Mode Input Range
Common-Mode Rejection Ratio
Supply Current
SYMBOL
V
CC
MAX4070
V
CC
= V
RS+
=
V
RS-
= 12V
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= T
MIN
to T
MAX
1.35
100
120
100
9
µA
10
0.1
0
2.4
75
50
30
0.5
5
µA
µA
mV
250
CONDITIONS
MAX4069/MAX4071/MAX4072 (Note 4)
MIN
2.7
3.6
0.08
TYP
MAX
24
24
0.25
0.8
1
24
V
dB
µA
mV
UNITS
V
V
OS
CMVR
CMRR
I
CC
Guaranteed by CMRR test
1.35V
≤
V
RS+
= V
RS-
≤
24V, V
CC
= 12V
V
CC
= V
RS+
= V
RS-
= 24V, R
L
= open,
T
A
= T
MIN
to T
MAX
V
CC
= V
RS+
= V
RS-
= 5.5V,
SHDN
= GND, T
A
= +25°C
V
CC
= V
RS+
= V
RS-
= 24V,
SHDN
= GND
V
RS+
= V
RS-
= 24V, V
CC
= 0V
V
CC
= V
RS+
= V
RS-
= 24V
Gain = 50V/V
Gain = 100V/V
Shutdown Supply Current
I
CC
SHDN
Leakage Current
Input Bias Current
Recommended Full-Scale Sense
Voltage (Note 6)
I
RS+,
I
RS-
V
SENSE
2
_______________________________________________________________________________________
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
ELECTRICAL CHARACTERISTICS (continued)
(V
RS
+ = V
RS
- = V
CC
= 2.7V to 24V, V
SENSE
= V
RS
+ - V
RS
- = 0V, I
REFOUT
= 0, V
SHDN
= V
CC
, V
GSEL
= GND, V
REFIN
= 2.5V (MAX4072),
T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C and at V
CC
= V
RS
+ = 12V.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
V
SENSE
= 75mV,
V
CC
= V
RS+
= 12V,
gain = 50
V
SENSE
= 50mV,
V
CC
= V
RS+
= 12V,
gain = 100
MAX4069/MAX4070/
MAX4072:
V
SENSE
= -35mV,
V
CC
= V
RS+
= 12V,
gain = 50
MAX4069/MAX4070/
MAX4072:
V
SENSE
= -17.5mV,
V
CC
= V
RS+
= 12V,
gain = 100
MAX4071:
V
SENSE
= -15mV,
V
CC
= V
RS+
= 12V,
gain = 50
MAX4071:
V
SENSE
= -7.5mV,
V
CC
= V
RS+
= 12V,
gain = 100
V
SENSE
= 3mV,
V
CC
= 12V, V
RS+
= 12V
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= T
MIN
to T
MAX
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= T
MIN
to T
MAX
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= T
MIN
to T
MAX
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= T
MIN
to T
MAX
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= T
MIN
to T
MAX
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= T
MIN
to T
MAX
T
A
= +25°C
±3
±2.0
±1.0
±0.8
±0.4
±0.25
MIN
TYP
±0.25
MAX
±1.0
±1.5
±2.0
±1.0
±1.5
±2.5
±1.0
±2.0
±3.0
±2.0
±4.0
±6
±2.5
±4.0
±6.0
±5
±10
±15
%
UNITS
MAX4069–MAX4072
Total OUT Voltage Error (Note 7)
_______________________________________________________________________________________
3
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
MAX4069–MAX4072
ELECTRICAL CHARACTERISTICS (continued)
(V
RS
+ = V
RS
- = V
CC
= 2.7V to 24V, V
SENSE
= V
RS
+ - V
RS
- = 0V, I
REFOUT
= 0, V
SHDN
= V
CC
, V
GSEL
= GND, V
REFIN
= 2.5V (MAX4072),
T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C and at V
CC
= V
RS
+ = 12V.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MAX4071,
V
CC
= 2.7V
MAX4069/MAX4070/
MAX4072,
V
CC
= 3.6V
MAX4071,
V
CC
= 2.7V
MAX4069/MAX4070/
MAX4072,
V
CC
= 3.6V
MAX4071,
V
CC
= 2.7V
MAX4069/MAX4070/
MAX4072,
V
CC
= 3.6V
MAX4071,
V
CC
= 2.7V
MAX4069/MAX4070/
MAX4072,
V
CC
= 3.6V
MIN
TYP
65
MAX
150
UNITS
I
OUT
= 10µA,
V
SENSE
= 100mV,
V
RS+
= V
CC
OUT Voltage High
V
CC
- V
OH
I
OUT
= 500µA,
V
SENSE
= 100mV,
V
RS+
= V
CC
65
150
mV
90
250
90
250
5
20
I
OUT
= -10µA,
V
SENSE
= -100mV,
V
RS+
= V
CC
OUT Voltage Low
V
OL
I
OUT
= -500µA,
V
SENSE
= -100mV,
V
RS+
= V
CC
5
20
mV
100
250
100
100
40
50
100
100
250
-3dB Bandwidth
Gain
Capacitive-Load Stability
Power-Supply Rejection Ratio
Logic Low Voltage (GSEL,
SHDN)
Logic High Voltage (GSEL,
SHDN)
Gain-Select Input Current
Shutdown Input Current
BW
A
V
Gain = 50V/V
V
SENSE
= 50mV,
V
CC
= 12V, C
L
= 100pF Gain = 100V/V
GSEL = GND
GSEL = V
CC
V
CC
= 2.7V to 24V
(MAX4069/MAX4071/MAX4072),
V
CC
= 3.6V to 24V (MAX4070)
V
CC
= 3.6V or 24V
V
CC
= 3.6V or 24V
GSEL = V
CC
= 24V or GND
SHDN
= V
CC
= 24V
SHDN
= GND, V
CC
= 24V
2
kHz
V/V
pF
dB
0.6
V
V
µA
µA
PSRR
V
IL
V
IH
I
GSEL
I
SHDN
100
120
0.01
3
0.01
1
12
1
4
_______________________________________________________________________________________
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
ELECTRICAL CHARACTERISTICS (continued)
(V
RS
+ = V
RS
- = V
CC
= 2.7V to 24V, V
SENSE
= V
RS
+ - V
RS
- = 0V, I
REFOUT
= 0, V
SHDN
= V
CC
, V
GSEL
= GND, V
REFIN
= 2.5V (MAX4072),
T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C and at V
CC
= V
RS
+ = 12V.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX4069–MAX4072
REFOUT (MAX4069/MAX4070/MAX4071)
MAX4069,
V
CC
= 12V
(Note 2)
Reference Output Voltage
V
REF
MAX4070,
V
CC
= 12V
MAX4071,
V
CC
= 12V
Reference Output Voltage
Temperature Coefficient
Load Regulation
Line Regulation
REF Capacitive-Load Stability
Reference Adjust Voltage
Threshold
Reference Output Voltage Range
Reference Adjust Input Current
REFIN (MAX4072 only)
Input-Voltage Range
Input Current
V
CC
= 12V
REFIN = 2.5V, V
CC
= 12V
1
-60
4
+20
V
µA
I
ADJ
V
ADJ
MAX4069, V
CC
= 12V
MAX4069, range adjustable with R1 and R2,
V
CC
= 12V
MAX4069, V
CC
= 12V, V
ADJ
= 1.23V
TCV
REF
ΔV
REFOUT
/ΔI
REF
ΔV
REF/
ΔV
CC
V
CC
= 12V
T
A
= +25°C
T
A
= T
MIN
to T
MAX
T
A
= +25°C
T
A
= T
MIN
to T
MAX
T
A
= +25°C
T
A
= T
MIN
to T
MAX
-40°C
≤
T
A
≤
+85°C
T
A
= T
MIN
to T
MAX
2.44
2.39
2.45
2.40
1.47
1.44
15
20
2
4
20
500
1.230
V
ADJ
to
+4
100
1.5
2.5
2.49
2.54
2.59
2.55
2.60
1.53
1.56
ppm/°C
mV/mA
µV/V
pF
V
V
nA
V
I
REFOUT
= 0 to 500µA
I
REFOUT
= 0 to -100µA
2.7V
≤
V
CC
≤
24V
All devices are 100% tested at T
A
= +25°C. Limits over temperature are guaranteed by design.
R1 = 215kΩ, R2 = 210kΩ for the MAX4069 only (see
Functional Diagram).
This sets REFOUT to 2.49V nominal.
Guaranteed by the PSRR test.
The REFOUT voltage for the MAX4069 should be set such that it does not exceed V
CC
- 1.1V. Similarly, the maximum REFIN
voltage for the MAX4072 should also be less than V
CC
- 1.1V.
Note 5:
Input-Referred Offset Voltage is defined as the voltage difference between OUT and REFOUT, divided by the selected gain
of either 50 or 100, when V
SENSE
= V
RS+
- V
RS-
= 0V.
Note 6:
The negative full-scale sense voltage is limited by the voltage range of OUT from V
REFOUT
to GND.
Note 7:
Total OUT Voltage Error is the sum of offset voltage and gain errors. The output voltage is measured relative to the reference
(REFOUT or REFIN).
Note 1:
Note 2:
Note 3:
Note 4:
_______________________________________________________________________________________
5