Datasheet

that swings above V
REF
voltage for positive-sense volt-
ages and below V
REF
for negative-sense voltages.
V
OUT
is equal to V
REF
when V
SENSE
is equal to zero.
Set the full-scale output range by selecting R
SENSE
and
the appropriate gain version of the MAX4080/
MAX4081.
76V, High-Side, Current-Sense Amplifiers with
Voltage Output
MAX4081T
V
SENSE
I
CHARGE
I
LOAD
R
SENSE
V
CC
GND
RS+RS-
OUT
REF1A
REF1B
5V
SYSTEM LOAD
AND CHARGER
BATTERY
V
OUT
= V
GND
V
OUT
= 10V
V
REF1A
= V
REF1B
= 5V
DISCHARGE CURRENT
4.5V TO 76V
V
OUT
- V
REF
CHARGE CURRENT
5V
10V
-250mV 250mV
-5V
V
SENSE
Figure 1. MAX4081T OUT Transfer Curve
R
SENSE
V
SENSE
I
LOAD
OUT
R
G1
R
G2
RS-
Q1
RS+
CURRENT
MIRROR
A1
I
A2
A3A2
MAX4080
V
SENSE
R
G1
R
G2
V
REF
RS-
REF1B
OUT
GND
REF1A
Q1 Q2
RF
125kΩ
125kΩ
RS+
CURRENT
MIRROR
CURRENT
MIRROR
A1
A2
MAX4081
Figure 3. MAX4081 Functional Diagram
Figure 2. MAX4080 Functional Diagram
Note: For Gain = 5 (F), R
G1
= R
G2
= 160k.
For Gain = 20 (T), R
G1
= R
G2
= 60k.
For Gain = 60 (S), R
G1
= R
G2
= 20k
.
MAX4080/MAX4081
10
Maxim Integrated