Datasheet

Low-Cost, SOT23, Voltage-Output,
High-Side Current-Sense Amplifier
amp’s supply voltage range should be at least as high
as any voltage the system may encounter.
The percent error introduced by output loading is
determined with the following formula:
where R
LOAD
is the external load applied to OUT.
Current Source Circuit
Figure 3 shows a block diagram using the MAX4173
with a switching regulator to make a current source.
% 100
R
12k R
1
ERROR
LOAD
LOAD
=
Ω+
−
⎛
⎝
⎜
⎞
⎠
⎟
Table 1. Recommended Component Values
MAX4173T
V
SENSE
R
SENSE
+3V TO +28V
0.1µF
RS+
+
0.3 in. COPPER
INPUT LOAD/BATTERY
0.3 in. COPPER0.1 in. COPPER
RS-
GND
OUT
V
CC
_
Figure 2. MAX4173 Connections Showing Use of PC Board Figure 3. Current Source
MAX4173
R
SENSE
I
LOAD
0 TO +28V
V
SENSE
V
CC
OUT
V
IN
GND
RS+
+3V TO +28V
0.1µF
RS-
LOAD/
BATTERY
LOW-COST
SWITCHING
REGULATOR
10.0100
5.050
2.0
10 10
20
10.0100
5.050
2.0
5 20
20
10.0100
5.050
2.0
1 100
20
10.0100
5.0501000
CURRENT-SENSE RESISTOR
R
SENSE
(m
ΩΩ
)
20
GAIN
2.0
0.1
FULL-SCALE OUTPUT VOLTAGE
(FULL-SCALE V
SENSE
= 100mV)
V
OUT
(V)
FULL-SCALE LOAD CURRENT
I
LOAD
(A)
8
Maxim Integrated
MAX4173