MAX4069 Datasheet, PDF (1/16 Pages) Maxim Integrated Products – Bidirectional, High-Side, Current-Sense Amplifiers with Reference

19-2423; Rev 2; 1/03
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.
Applications
Notebook Fuel Gauging
Smart-Battery Packs/Chargers
Motor Control
Power-Management Systems
Cell-Phone Battery-Current Monitoring
Selector Guide
PART
MAX4069
MAX4070
MAX4071
MAX4072
REFERENCE
ADJUSTABLE
2.5V
1.5V
EXTERNAL
SUPPLY
VOLTAGE
RANGE (V)
2.7 to 24
3.6 to 24
2.7 to 24
2.7 to 24
COMMON-
MODE RANGE
(V)
1.35 to 24
1.35 to 24
1.35 to 24
1.35 to 24
Pin Configurations appear at end of data sheet.
Features
o Bidirectional, Compact, Current-Sense Solution
o Total Output Error Less than 1.5%
o Selectable Gain of 50V/V or 100V/V
o Wide 1.35V to 24V Common-Mode Range
Independent of Supply Voltage
o 2.7V to 24V Single-Supply Operation
o Internal Precision Reference
Adjustable (MAX4069)
2.50V (MAX4070)
1.50V (MAX4071)
o Low 100µA Supply Current
o 10µA Supply Current in Shutdown
o Available in Space-Saving Packages
8-Pin Thin QFN (MAX4070/MAX4071/MAX4072)
8-Pin µMAX (MAX4070/MAX4071MAX4072)
10-Pin µMAX (MAX4069)
Ordering Information
PART
MAX4069AUB
MAX4070AUA
MAX4070ATA
TEMP RANGE PIN-PACKAGE
-40°C to +125°C 10 µMAX
-40°C to +125°C 8 µMAX
-40°C to +125°C 8 Thin QFN-EP*
TOP
MARK
—
—
ABN
MAX4071AUA -40°C to +125°C 8 µMAX
—
MAX4071ATA -40°C to +125°C 8 Thin QFN-EP* ABO
MAX4072AUA -40°C to +125°C 8 µMAX
—
MAX4072ATA -40°C to +125°C 8 Thin QFN-EP* ABP
*EP = Exposed paddle.
Typical Operating Circuit
VBATT = 1.35V TO 24V
RSENSE
FROM BATTERY
CHARGER
RS-
RS+
LOAD
VCC = 3.6V TO 24V
VCC
MAX4070
GSEL
OUT
TO ADC
SHDN
REFOUT
2.5V
GND
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