MAX4080 Maxim, MAX4080 Datasheet - Page 11

• Manufacturer Part Number: MAX4080
• Description: The MAX4080/MAX4081 are high-side, current-sense amplifiers with an input voltage range that extends from 4
• Manufacturer: Maxim

Table 1. Typical Component Values
For the bidirectional MAX4081, the V
is controlled by REF1A and REF1B. V
the average voltage of V
REF1A and REF1B to a low-noise, regulated voltage
source to set the output reference level. In this mode,
V
Figure 4).
Alternatively, connect REF1B to ground, and REF1A to a
low-noise, regulated voltage source. In this case, the out-
put reference level (V
two. V
In either mode, the output swings above the reference
voltage for positive current-sensing (V
output swings below the reference voltage for negative
current-sensing (V
OUT
CURRENT, I
CURRENT, I
FULL-SCALE LOAD
FULL-SCALE LOAD
76V, High-Side, Current-Sense Amplifiers with
OUT
equals V
50.000
12.500
10.000
50.000
25.000
10.000
0.500
0.125
0.050
5.000
1.250
0.500
5.000
1.000
0.250
0.100
2.500
1.000
equals V
LOAD
LOAD
External References (MAX4081)
REF1A
RS+
______________________________________________________________________________________
REF1A
(A)
(A)
REF
< V
when V
) is equal to V
/2 when V
RS-
REF1A
CURRENT-SENSE
CURRENT-SENSE
).
RESISTOR (mΩ)
RESISTOR (mΩ)
SENSE
and V
SENSE
1000
1000
1000
1000
1000
1000
100
100
100
100
100
100
10
10
10
10
10
10
OUT
equals zero (see
REF
RS+
REF1A
REF1B
equals zero.
reference level
is defined as
> V
divided by
. Connect
RS-
). The
GAIN
GAIN
(V/V)
(V/V)
20
60
20
60
20
60
20
60
20
60
20
60
5
5
5
5
5
5
Ideally, the maximum load current develops the full-
scale sense voltage across the current-sense resistor.
Choose the gain needed to yield the maximum output
voltage required for the application:
where V
for gain of 5V/V, 250mV for gain of 20V/V, 100mV for
gain of 60V/V, and A
In applications monitoring a high current, ensure that
R
tor’s power dissipation is exceeded, its value may drift
or it may fail altogether.
The MAX4080/MAX4081 sense a wide variety of cur-
rents with different sense-resistor values. Table 1 lists
common resistor values for typical operation.
SENSE
FULL-SCALE
FULL-SCALE
SENSE
is able to dissipate its own I
V
V
SENSE
(mV)
±500
±125
±500
±125
±500
±125
SENSE
(mV)
1000
1000
Recommended Component Values
±50
±50
±50
250
100
250
100
500
250
100
is the full-scale sense voltage, 1000mV
Applications Information
V
OUT
Voltage Output
V
is the gain of the device.
= V
SENSE
MAX4081 FULL-SCALE
MAX4080 FULL-SCALE
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE
(V
OUT

A
2
±2.5
±2.5
±3.0
±2.5
±2.5
±3.0
±2.5
±2.5
±3.0
V
R loss. If the resis-
- V
5.0
5.0
6.0
5.0
5.0
6.0
2.5
5.0
6.0
REF,
V)
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