Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
MAX4069
RS+
RS-
GSEL
SHDN
2.7V TO 24V
VCC
OUT
TO ADC
R1
R2
SHUTDOWN
GAIN SELECT
RSENSE
LOAD
FROM BATTERY
CHARGER
REFOUT
OA
ADJ
GND
VREF
1.23V
CSA
Functional Diagram
Pin Description
PIN
MAX4069
MAX4070/
MAX4071
MAX4072
NAME
FUNCTION
11
1
SHDN
Shutdown Input. Drive SHDN low to select shutdown mode. Connect SHDN
to VCC for normal operation.
2
RS-
Negative Connection to the External Sense Resistor
3
RS+
Positive Connection to the External Sense Resistor
4
—
N.C.
No Connection. Not internally connected.
5
4
GND
Ground. For thin QFN packages, also make an external connection from
GND to the under-side exposed paddle.
6
—
ADJ
Adjustable Output Voltage Feedback Input. Connect a resistor-divider
between REFOUT, ADJ, and GND (MAX4069 only, see Functional Diagram).
7
5
—
REFOUT Reference Output Voltage (MAX4069/MAX4070/MAX4071)
8
6
OUT
Voltage Output. The difference voltage, VOUT - VREF, is proportional to
the voltage difference between RS+ and RS- and indicates the correct
polarity.
97
7
VCC
Supply Voltage Input. Bypass VCC to GND with a 0.1F capacitor.
10
8
GSEL
Gain-Setting Input. Connect GSEL low to select gain = 50V/V, or connect
GSEL high to select gain = 100V/V.
—
5
REFIN Reference Input Voltage (MAX4072)
MAX4069–MAX4072
Maxim Integrated
9