INA117
INA
117
INA
117
www.ti.com
High Common-Mode Voltage
DIFFERENCE AMPLIFIER
FEATURES
APPLICATIONS
● COMMON-MODE INPUT RANGE:
±200V (VS = ±15V)
● PROTECTED INPUTS:
±500V Common-Mode
±500V Differential
● UNITY GAIN: 0.02% Gain Error max
● NONLINEARITY: 0.001% max
● CMRR: 86dB min
●
●
●
●
●
CURRENT MONITOR
BATTERY CELL-VOLTAGE MONITOR
GROUND BREAKER
INPUT PROTECTION
SIGNAL ACQUISITION IN NOISY
ENVIRONMENTS
● FACTORY AUTOMATION
DESCRIPTION
The INA117 is a precision unity-gain difference
amplifier with very high common-mode input voltage
range. It is a single monolithic IC consisting of a
precision op amp and integrated thin-film resistor
network. It can accurately measure small differential
voltages in the presence of common-mode signals up
to ±200V. The INA117 inputs are protected from
momentary common-mode or differential overloads
up to ±500V.
In many applications, where galvanic isolation is not
essential, the INA117 can replace isolation amplifiers.
This can eliminate costly isolated input-side power
supplies and their associated ripple, noise and quiescent current. The INA117’s 0.001% nonlinearity and
200kHz bandwidth are superior to those of conventional isolation amplifiers.
21.11kΩ
RefB
1
–In
2
+In
3
V–
4
380kΩ
8
Comp
7
V+
6
VO
5
RefA
380kΩ
380kΩ
20kΩ
The INA117 is available in 8-pin plastic mini-DIP and
SO-8 surface-mount packages, specified for the –40°C
to +85°C temperature range. The metal TO-99 models
are available specified for the –40°C to +85°C and
–55°C to +125°C temperature range.
Copyright © 2000, Texas Instruments Incorporated
SBOS154A
Printed in U.S.A. December, 2000
SPECIFICATIONS
At TA = +25°C, VS = ±15V, unless otherwise noted.
INA117AM, SM
PARAMETER
CONDITIONS
MIN
GAIN
Initial (1)
Error
vs Temperature
Nonlinearity (2)
OUTPUT
Rated Voltage
Rated Current
Impedance
Current Limit
Capacitive Load
IO = +20mA, –5mA
VO = 10V
To Common
Stable Operation
INPUT
Impedance
Differential
Common-Mode
Differential
Common-Mode, Continuous
Voltage Range
Common-Mode Rejection
DC
AC, 60Hz
vs Temperature, DC
AM, BM, P, KU
SM
10
+20, –5
INA117BM
TYP
MAX
1
0.01
2
0.0002
0.05
10
0.001
MIN
✻
✻
✻
✻
✻
12
TYP
INA117P, KU
MAX
MIN
✻
✻
✻
✻
0.02
✻
✻
✻
TYP
✻
✻
MAX
UNITS
V/V
%
ppm/°C
%
✻
✻
✻
V
mA
Ω
mA
pF
0.01
+49, –13
1000
✻
✻
✻
✻
✻
✻
800
400
✻
✻
✻
✻
✻
✻
kΩ
kΩ
V
V
✻
✻
dB
dB
✻
dB
dB
±10
±200
✻
✻
(3)
VCM = 400Vp-p
TA = TMIN to TMAX
OFFSET VOLTAGE
Initial
KU Grade (SO-8 Package)
vs Temperature
vs Supply
vs Time
RTO
DYNAMIC RESPONSE
Gain Bandwidth, –3dB
Full Power Bandwidth
Slew Rate
Settling Time: 0.1%
0.01%
0.01%
POWER SUPPLY
Rated
Voltage Range
Quiescent Current
TEMPERATURE RANGE
Specification: AM, BM, P, KU
SM
Operation
Storage
RTO
80
80
86
66
94
94
66
60
75
75
80
90
74
120
1000
8.5
90
200
40
80
✻
1000
✻
✻
✻
40
✻
✻
✻
600
✻
✻
✻
✻
2000
µV
µV
µV/°C
dB
µV/mo
(5)
✻
✻
25
550
✻
200
VO = 20Vp-p
VCM
✻
✻
(4)
TA = TMIN to TMAX
VS = ±5V to ±18V
OUTPUT NOISE VOLTAGE
fB = 0.01Hz to 10Hz
fB = 10kHz
70
66
30
2
VO = 10V Step
VO = 10V Step
= 10V Step, VDIFF = 0V
Derated Performance
VO = 0V
±5
2.6
6.5
10
4.5
±15
1.5
–25
–55
–55
–65
✻
✻
✻
✻
✻
✻
✻
✻
✻
±18
2
✻
+85
+125
+125
+150
✻
✻
µVp-p
nV/√Hz
✻
kHz
kHz
V/µs
µs
µs
µs
✻
✻
✻
✻
✻
V
V
mA
✻
✻
✻
✻
✻
–40
+85
✻
✻
✻
✻
–40
–55
+85
+125
✻
✻
✻
✻
°C
°C
°C
°C
✻Specification same as for INA117AM.
NOTES: (1) Connected as difference amplifier (see Figure 1). (2) Nonlinearity is the maximum peak deviation from the best-fit straight line as a percent of full-scale
peak-to-peak output. (3) With zero source impedance (see discussion of common-mode rejection in Application Information section). (4) Includes effects of amplifier’s
input bias and offset currents. (5) Includes effects of amplifier’s input current noise and thermal noise contribution of resistor network.
2
INA117
SBOS154A
PIN CONFIGURATION
Top View
TO-99
INA117AM, BM, SM
Tab
8
Ref B
–In
Top View
DIP/SO
INA117P, KU
Comp
1
7
V+
2
6
3
RefB
1
8
Comp
–In
2
7
V+
+In
3
6
Output
V–
4
5
RefA
Output
5
Ref A
+In
4
V–
Case internally connected to V–. Make no connection.
ELECTROSTATIC
DISCHARGE SENSITIVITY
ABSOLUTE MAXIMUM RATINGS
Supply Voltage .................................................................................. ±22V
Input Voltage Range, Continuous ................................................... ±200V
Common-Mode and Differential, 10s ........................................... ±500V
Operating Temperature
M Metal TO-99 ................................................................ –55 to +125°C
P Plastic DIP and U SO-8 ................................................ –40 to +85°C
Storage Temperature
M Package ....................................................................... –65 to +150°C
P Plastic DIP and U SO-8 .............................................. –55 to +125°C
Lead Temperature (soldering, 10s) ............................................... +300°C
Output Short Circuit to Common ............................................. Continuous
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling
and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits
may be more susceptible to damage because very small
parametric changes could cause the device not to meet its
published specifications.
PACKAGE/ORDERING INFORMATION
PRODUCT
INA117P
INA117KU
"
PACKAGE
DRAWING
NUMBER
SPECIFIED
TEMPERATURE
RANGE
DIP-8
006
–40°C to +85°C
INA117P
INA117P
Rails
SO-8 Surface-Mount
182
"
INA117KU
INA117KU
Rails
PACKAGE
PACKAGE
MARKING
ORDERING
NUMBER(1)
TRANSPORT
MEDIA
"
"
"
"
INA117KU/2K5
Tape and Reel
INA117AM
TO-99 Metal
001
–25°C to +85°C
INA117AM
INA117AM
Rails
INA117BM
"
"
"
INA117BM
INA117BM
Rails
INA117SM
"
"
–55°C to +125°C
INA117SM
INA117SM
Rails
NOTE: (1) Models with a slash (/) are available only in Tape and Reel in the quantities indicated (e.g., /2K5 indicates 2500 devices per reel). Ordering 2500
pieces of “INA117KU/2K5” will get a single 2500-piece Tape and Reel.
INA117
SBOS154A
3
TYPICAL PERFORMANCE CURVES
At TA = +25°C, VS = ±15V, unless otherwise noted.
COMMON-MODE REJECTION vs FREQUENCY
POWER-SUPPLY REJECTION vs FREQUENCY
100
INA117BM
Power-Supply Rejection (dB)
Common-Mode Rejection (dB)
100
90
80
INA117AM, SM, P, KU
70
60
50
40
100
1k
10k
100k
V+
70
60
50
2M
1
10
100
1k
10k
Frequency (Hz)
Frequency (Hz)
POSITIVE COMMON-MODE VOLTAGE RANGE
vs POSITIVE POWER-SUPPLY VOLTAGE
NEGATIVE COMMON-MODE VOLTAGE RANGE
vs NEGATIVE POWER-SUPPLY VOLTAGE
–400
TA = –55°C
350
TA = +25°C
300
Max Rating = 200V
250
TA = +125°C
200
150
–VS = –5V to –20V
100
50
Negative Common-Mode Range (V)
400
Positive Common-Mode Range (V)
V–
80
40
20
–350
TA = +25°C
–300
Max Rating = –200V
–250
TA = –55°C to +125°C
–200
–150
+VS = +5V to +20V
–100
–50
5
10
15
Positive Power-Supply Voltage (V)
4
90
20
–5
–10
–15
–20
Negative Power-Supply Voltage (V)
INA117
SBOS154A
TYPICAL PERFORMANCE CURVES (Cont.)
At TA = +25°C, VS = ±15V, unless otherwise noted.
SMALL SIGNAL STEP RESPONSE
CL = 0
SMALL SIGNAL STEP RESPONSE
CL = 1000pF
LARGE SIGNAL STEP RESPONSE
INA117
SBOS154A
5
APPLICATION INFORMATION
Figure 1 shows the basic connections required for operation.
V–
Applications with noisy or high-impedance power-supply lines
may require decoupling capacitors close to the device pins.
V+
4
The output voltage is equal to the differential input voltage between pins 2 and 3. The common mode input
voltage is rejected.
2
V2
Internal circuitry connected to the compensation pin 8 cancels the parasitic distributed capacitance between the feedback resistor, R2, and the IC substrate. For specified dynamic performance, pin 8 should be grounded or connected
through a 0.1µF capacitor to an AC ground such as V+.
380kΩ
6
380kΩ
3
V3
7
380kΩ
VO = V3 – V2
21.1kΩ
20kΩ
8
–15V
1
+15V
5
100kΩ
+15V
(a)
+
+
1µF
Tantalum
4
2
7
R1
380kΩ
10Ω
1µF
Tantalum
R2
380kΩ
V–
V+
4
–In = V2
R3
3
2
6
380kΩ
VO = V 3 – V 2
7
380kΩ
380kΩ
V2
+In = V3
R5
21.1kΩ
50kΩ
±1.5mV
Range
–15V
R4
20kΩ
3
6
380kΩ
VO = V3 – V2
V3
8
1
5
V+
21.1kΩ
8
20kΩ
1
100µA
1/2 REF200
5
FIGURE 1. Basic Power and Signal Connections.
100Ω
COMMON-MODE REJECTION
Common-mode rejection (CMR) of the INA117 is dependent on the input resistor network, which is laser-trimmed for
accurate ratio matching. To maintain high CMR, it is important to have low source impedances driving the two inputs.
A 75Ω resistance in series with pin 2 or 3 will decrease CMR
from 86dB to 72dB.
(b)
OPA27
±10mV
10kΩ
100µA
1/2 REF200
Resistance in series with the reference pins will also degrade
CMR. A 4Ω resistance in series with pin 1 or 5 will decrease
CMRR from 86dB to 72dB.
Most applications do not require trimming. Figures 2 and 3
show optional circuits that may be used for trimming offset
voltage and common-mode rejection.
TRANSFER FUNCTION
Most applications use the INA117 as a simple unity-gain
difference amplifier. The transfer function is:
VO = V3 – V2
100Ω
Offset adjustment is regulated—
insensitive to power supply variations.
V–
FIGURE 2. Offset Voltage Trim Circuits.
Some applications, however, apply voltages to the reference
terminals (pins 1 and 5). A more complete transfer function
is:
VO = V3 – V2 + 19 • V5 – 18 • V1
V5 and V1 are the voltages at pins 5 and 1.
V3 and V2 are the voltages at pins 3 and 2.
6
INA117
SBOS154A
MEASURING CURRENT
The INA117 can be used to measure a current by sensing the
voltage drop across a series resistor, RS. Figure 4 shows the
INA117 used to measure the supply currents of a device
under test. The circuit in Figure 5 measures the output
current of a power supply. If the power supply has a sense
connection, it can be connected to the output side of RS to
eliminate the voltage-drop error. Another common application is current-to-voltage conversion, as shown in Figure 6.
V–
V+
(+200V max)
+VS
4
7
380kΩ
2
380kΩ
C
RS
RC*
6
380kΩ
3
VO = RS IDUT+
IDUT+
21.1kΩ
V–
V+
8
4
V2
2
20kΩ
1
5
7
380kΩ
Device
Under
Test
380kΩ
V+
V–
4
6
V3
3
380kΩ
380kΩ
2
21.1kΩ
8
10Ω
RS
6
380kΩ
3
5
200Ω
380kΩ
RC*
20kΩ
1
7
IDUT–
VO = V3 – V2
VO = RS IDUT–
CMR
Adjust
21.1kΩ
10Ω
8
–VS
20kΩ
1
5
(–200V max)
If offset adjust is also required,
connect to offset circuit, Figure 2.
*Not needed if R S is less than 20Ω —see text.
FIGURE 4. Measuring Supply Currents of Device Under
Test.
FIGURE 3. CMR Trim Circuit.
V–
V+
4
7
Power Supply
±200V max
2
Out
380kΩ
380kΩ
Sense
RS
RC*
Optional Load
Sense Connection
(see text)
3
6
380kΩ
VO = IL RS
IL
21.1kΩ
20kΩ
Load
8
1
5
*RC = RS not needed if RS is less than 20Ω—see text.
FIGURE 5. Measuring Power Supply Output Current.
INA117
SBOS154A
7
VS
(±200V max)
2
380kΩ
380kΩ
RS
250Ω
3
250Ω
RC*
4 to 20mA
6
380kΩ
VO = 1V to 5V
21.1kΩ
8
20kΩ
1
5
VS
(a)
(±200V max)
*Not needed if RS is less than 20Ω—see text.
2
380kΩ
380kΩ
250Ω
RC *
RS
250Ω
3
6
380kΩ
VO = –1V to –5V
4 to 20mA
21.1kΩ
8
20kΩ
1
5
(b)
4 to 20mA
2
380kΩ
380kΩ
*Not needed if RS is less than 20Ω—see text.
250Ω
RC *
RS
250Ω
3
6
380kΩ
VO = 1V to 5V
20kΩ
21.1kΩ
8
VS
1
5
(±200V max)
4 to 20mA
(c)
*Not needed if RS is less than 20Ω—see text.
2
380kΩ
380kΩ
RS
250Ω
6
3
380kΩ
VO = –1V to –5V
250Ω
RC *
21.1kΩ
VS
(±200V max)
8
20kΩ
1
5
(d)
*Not needed if RS is less than 20Ω—see text.
FIGURE 6. Current to Voltage Converter.
8
INA117
SBOS154A
Example: For a 1V/mA transfer function, the nominal,
uncorrected value for RS would be 1kΩ. A slightly larger
value, RS' = 1002.6Ω, compensates for the gain error due to
loading.
In all cases, the sense resistor imbalances the input resistor
matching of the INA117, degrading its CMR. Also, the input
impedance of the INA117 loads RS, causing gain error in the
voltage-to-current conversion. Both of these errors can be
easily corrected.
The 380kΩ term in the equation for RS' has a tolerance of
±25%, so sense resistors above approximately 400Ω may
require trimming to achieve gain accuracy better than 0.02%.
The CMR error can be corrected with the addition of a
compensation resistor, RC, equal in value to RS as shown in
Figures 4, 5, and 6. If RS is less than 20Ω, the degradation
in CMR is negligible and RC can be omitted. If RS is larger
than approximately 2kΩ, trimming RC may be required to
achieve greater than 86dB CMR. This is because the actual
INA117 input impedances have 1% typical mismatch.
Of course, if a buffer amplifier is added as shown in Figure
7, both inputs see a low source impedance, and the sense
resistor is not loaded. As a result, there is no gain error or
CMR degradation. The buffer amplifier can operate as a
unity gain buffer or as an amplifier with non-inverting gain.
Gain added ahead of the INA117 improves both CMR and
signal-to-noise. Added gain also allows a lower voltage drop
across the sense resistor. The OPA1013 is a good choice for
the buffer amplifier since both its input and output can swing
close to its negative power supply.
If RS is more than approximately 100Ω, the gain error will
be greater than the 0.02% specification of the INA117. This
gain error can be corrected by slightly increasing the value
of RS. The corrected value, RS', can be calculated by:
R S' =
R S • 380 kΩ
380 kΩ – R S
–15V
V1
+15V
4
7
I
380kΩ
2
VX
V1
–21V to +10V
–5V to –36V
–20V to –51V
+15V
Ground
–15V
380kΩ
R2 *
RS
6
380kΩ
3
VO = I • RS • (1 +
1/2
OPA1013
21.1kΩ
R1 *
8
–VX
Op amp power can be derived with voltagedropping zener diode if –VX power is relatively
constant.
|VX| = (5V to 36V) + VZ
e.g., If VZ is 50V then VX = –55V to –86V.
R2
)
R1
20kΩ
1
5
*Or connect as buffer (R2 = 0, omit R1).
Regulated power for op amp allows –VX
power to vary over wide range.
180k Ω
VZ
VX = –30V to –200V
MPS-A42
0.01µF
IN4702
or
–VX
V–
V+
4
2
I
7
380kΩ
380kΩ
RS
3
6
380kΩ
V O = I • RS
1/2
OPA1013
0.1µF
21.1kΩ
8
20kΩ
1
5
–VX
FIGURE 7. Current Sensing with Input Buffer.
INA117
SBOS154A
9
Figure 8 shows very high input impedance buffer used to
measure low leakage currents. Here, the buffer op amp is
powered with an isolated, split-voltage power supply. Using
an isolated power supply allows full ±200V common-mode
input range.
these resistors produces approximately 550nV/√Hz noise.
The internal op amp contributes virtually no excess noise at
frequencies above 100Hz.
Many applications may be satisfied with less than the full
200kHz bandwidth of the INA117. In these cases, the noise
can be reduced with a low-pass filter on the output. The twopole filter shown in Figure 9 limits bandwidth to 1kHz and
reduces noise by more than 15:1. Since the INA117 has a
1/f noise corner frequency of approximately 100Hz, a cutoff
frequency below 100Hz will not further reduce noise.
NOISE PERFORMANCE
The noise performance of the INA117 is dominated by the
internal resistor network. The thermal or Johnson noise of
±200V max
1kΩ
+15V
100MΩ
+15V
Isolated DC/DC Converter
9kΩ
D1,2*
PWS725
Com
OPA111
–15V
IL
100kΩ
Device
Under
Test
2
*D1 and D2 are each a 2N3904 transistor
base-collector junction (emitter open).
3
380kΩ
380kΩ
6
380kΩ
eO = IL x 109
(1V/nA)
21.1kΩ
20kΩ
INA117
8
1
5
FIGURE 8. Leakage Current Measurement Circuit.
V+
V–
4
V2
V3
2
3
7
380kΩ
C2
0.02µF
380kΩ
6
380kΩ
R1
11.0kΩ
R2
11.3kΩ
OPA27
2-Pole Butterworth
Low-Pass Filter
C1
0.01µF
21.1kΩ
8
VO = V2 – V3
20kΩ
1
5
BUTTERWORTH
LOW-PASS
OUTPUT NOISE
f–3dB
(mVp-p)
200kHz
100kHz
10kHz
1kHz
≤100Hz(1)
See Application Bulletin AB-017 for other filters.
1.8
1.1
0.35
0.11
0.05
R1
11kΩ
11kΩ
11kΩ
11kΩ
R2
C1
No Filter
11.3kΩ
100pF
11.3kΩ
1nF
11.3kΩ
10nF
11.3kΩ
0.1µF
C2
200pF
2nF
20nF
0.2µF
NOTE: (1) Since the INA117 has a 1/f noise corner frequency of approximately 100Hz,
bandwidth reduction below this frequency will not significantly reduce noise.
FIGURE 9. Output Filter for Noise Reduction.
10
INA117
SBOS154A
V2
380kΩ
2
380kΩ
V–
V+
4
V3
6
380kΩ
3
VO =
1+
19 R7
380kΩ
2
V2
R6
21.1kΩ
7
V3 – V 2
380kΩ
20kΩ
INA117
8
1
5
R7
V3
R6
6
380kΩ
3
VO = V3 – V2 + VX
21.1kΩ
OPA27
Refer to Application
Bulletin AB-001 for
details.
GAIN
(V/V)
R7
(kΩ)
R6
(kΩ)
1/2
1/4
1/5
1.05
3.16
4.22
20
20
20
20kΩ
INA117
8
1
5
OPA27
VX
FIGURE 11. Summing VX in Output.
FIGURE 10. Reducing Differential Gain.
V2
2
R1
380kΩ
3
R3
380kΩ
Refer to Application Bulletin AB-010 for details.
(a)
R2
380kΩ
6
VOUT = V3 – V2
V3
R5
21.1kΩ
V2
V3
2
R1
380kΩ
R2
380kΩ
R4
20kΩ
INA117
8
1
5
100pF
3
R3
380kΩ
R6
5kΩ
6
VOUT = V3 – V2
R4
20kΩ
R5
21.1kΩ
A1
OPA27
R9
400kΩ
8
1
5
R10
10kΩ
100pF
R6
5kΩ
R7
10kΩ
–V3 /20
100pF
INA117
R8
10kΩ
A2
OPA27
(b)
R7
10kΩ
VCM /20
A1
OPA27
FIGURE 12. Common-Mode Voltage Monitoring.
INA117
SBOS154A
11
+9V
7
2
V2
380kΩ
380kΩ
7
VCM Range =
+50V to +200V
(VS ±9V)
3
V3
21.1kΩ
(a)
2
6
380kΩ
25kΩ
25kΩ
5
6
20kΩ
VO = V3 – V2
INA117
8
1
5
4
3
25kΩ
–3V > VO > –6V swap A2 pins
2 and 3 for +4V > VO > 3V.
INA105
25kΩ
1
4
–9V
+9V
7
2
V2
380kΩ
380kΩ
7
VCM Range =
–12V to +200V
(VS = ±9V)
3
V3
6
380kΩ
2
25kΩ
25kΩ
5
6
21.1kΩ
(b)
INA117
8
VO = V3 – V2
20kΩ
1
5
4
3
25kΩ
25kΩ
1N4684
3.3V
(V–) +3.3V
0V > VO > –6V swap A2 pins
2 and 3 for +4V > VO > 0V.
INA105
10kΩ
1
4
–9V
V2
2
380kΩ
380kΩ
VCM Range = ±200V
(VS = ±9V)
V3
3
6
380kΩ
21.1kΩ
2
25kΩ
25kΩ
5
6
20kΩ
VO = V3 – V2
INA117
(c)
8
1
5
3
R7
1MΩ
25kΩ
25kΩ
INA105
1
13.7kΩ
(VS = ±9V)
Refer to Application Bulletin AB-015 for details.
R8
1MΩ
OPA602
FIGURE 13. Offsetting or Boosting Common-Mode Voltage Range for Reduced Power-Supply Voltage Operation.
12
INA117
SBOS154A
+200V max
V–
V+
4
2
7
380kΩ
380kΩ
+
–
3
6
380kΩ
21.1kΩ
20kΩ
INA117
8
1
5
V–
V+
4
2
7
380kΩ
380kΩ
+
6
–
3
380kΩ
21.1kΩ
20kΩ
INA117
Repeat
for each
cell
8
1
eO = Cell Voltage
5
MUX
V–
V+
4
2
7
380kΩ
380kΩ
+
–
3
6
380kΩ
21.1kΩ
20kΩ
INA117
8
1
5
Cell Select
V–
V+
4
2
7
380kΩ
380kΩ
+
–
3
6
380kΩ
21.1kΩ
20kΩ
INA117
8
1
5
–200V max
FIGURE 14. Battery Cell Voltage Monitor.
INA117
SBOS154A
13
VS (200V max)
+15V –15V
7
2
4
380kΩ
380kΩ
R1
0.1Ω
3
6
380kΩ
–0.1 (I1)
I1
20kΩ
21.1kΩ
INA117
8
1
Load
A1
VIN
5
ILOAD = I1 – I2
+15V
7
+15V
–15V
7
4
–15V
4
I2
2
380kΩ
100kΩ
380kΩ
2
R2
0.1Ω
5
10kΩ
6
6
3
380kΩ
3
–0.1 (I2)
10kΩ
VO
VO = I 1 – I2
= ILOAD
100kΩ
21.1kΩ
INA106
20kΩ
1
INA117
8
1
5
VS (–200V max)
FIGURE 15. Measuring Amplifier Load Current.
V2
V3
2
3
R1
380kΩ
R2
380kΩ
R3
380kΩ
6
VOUT = V3 – V2
R5
21.1kΩ
R4
20kΩ
INA117
8
1
5
C1
R1
0.47µF
1MΩ
OPA602
Refer to Application
Bulletin AB-008 for
details.
FIGURE 16. AC-Coupled INA117.
14
INA117
SBOS154A
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