SI8540-B-FSR Silicon Laboratories Inc, SI8540-B-FSR Datasheet - Page 7

• Manufacturer Part Number: SI8540-B-FSR
• Description: IC CURRENT SENSOR AMP 8SOIC
• Manufacturer: Silicon Laboratories Inc

Specifications of SI8540-B-FSR

• Amplifier Type: Current Sense
• Number Of Circuits: 1
• Current - Supply: 90µA
• Current - Output / Channel: 10mA
• Voltage - Supply, Single/dual (±): 5 V ~ 36 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Output Type: -
• -3db Bandwidth: -
• Slew Rate: -
• Gain Bandwidth Product: -
• Current - Input Bias: -
• Voltage - Input Offset: -

3. Functional Description
The Si8540 is designed to operate over an input common-mode range of 5 to 36 V. Figure 2 shows an example
Si8540 application with external sense resistor, R
output scaling resistor, R
R
internal current sense amplifier measures the differential input voltage, V
proportional to I
gain. The Si8540 is placed in a low-power shutdown mode when SHDN is at V
3.1. Application Information
The Si8540 can sense a wide range of currents with different sense resistor values. Table 3 lists typical operational
values.
G2
Full-scale
I
SENSE
Current
) is negligible compared to I
Load
0.1
10
1
5
Table 3. Recommended Current Sense Resistor for a Given Full-Scale Load Current
(A)
R
LOAD
SENSE
Resistor
Current-
Sense
1000
100
20
. Resistor R
5
(m)
OUT
. The supply current flowing into the Si8540 inverting and non-inverting inputs (R
RG1 = RG2 ()
SHDN
LOAD
Gain-Setting
OUT
Resistors,
Figure 2. Si8540 Application Circuit
200
200
100
converts this current to a voltage, and its value determines the output signal
50
and, as a result, has no appreciable effect on measurement accuracy. The
Si8540
Control
SENSE
SOURCE
Resistor,
Output
R
(k)
Rev. 1.1
OUT
5
5
2
2
, external current gain-setting resistors, R
RG1
R
G1
+ _
R
SENSE
GND
Full-Scale
RG2
V
Voltage,
R
Output
G2
OUT
2.5
2.5
2
2
(V)
LOAD
I
OUT
LOAD
SENSE
V
V
R
IH
I
OUT
OUT
OUT
OUT
, and generates an output current
.
Factor
Scale
(V/A)
2.5
0.4
0.2
25
/I
SENSE
Typical Error at 1, 10
1%
10
10
and 100% of Full
5
5
G1
Load (%)
Si8540
10%
and R
1
1
1
1
G2
100%
0.2
0.2
0.2
0.4
, and
G1
7
,