MAX4069–MAX4072
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
General Description
The MAX4069–MAX4072 low-cost, bidirectional, highside, current-sense amplifiers are ideal for monitoring
battery charge and discharge currents in notebooks,
cell phones, and other portable equipment. They feature 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 VCC, while discharge current is given from
2.5V to GND. The MAX4071 is similar, but with a reference 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® Diagrams
Functional package.
Applications
Notebook Fuel Gauging
Smart-Battery Packs/Chargers
Features
♦ Bidirectional, Compact, Current-Sense Solution
♦ 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)
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX4069AUB
-40°C to +125°C 10 µMAX
MAX4070AUA
-40°C to +125°C 8 µMAX
MAX4070ATA
-40°C to +125°C 8 Thin QFN-EP*
MAX4071AUA
-40°C to +125°C 8 µMAX
MAX4071ATA
-40°C to +125°C 8 Thin QFN-EP*
MAX4072AUA
-40°C to +125°C 8 µMAX
—
ABN
—
ABO
—
MAX4072ATA
-40°C to +125°C 8 Thin QFN-EP*
*EP = Exposed pad.
ABP
Typical Operating Circuit
Motor Control
Power-Management Systems
Cell-Phone Battery-Current Monitoring
TOP
MARK
—
FROM BATTERY
CHARGER
RSENSE
VBATT = 1.35V TO 24V
RS-
VCC = 3.6V TO 24V
RS+
LOAD
VCC
MAX4070
GSEL
µMAX is a registered trademark of Maxim Integrated Products, Inc.
Pin Configurations appear at end of data sheet.
Functional Diagramsand Selector Guide appear at end of
Pin Configurations continued at end of data sheet.
UCSP sheet.
data is a trademark of Maxim Integrated Products, Inc.
OUT
SHDN
REFOUT
TO ADC
2.5V
GND
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-2423; Rev 3; 11/08