OP1177ARMZ Analog Devices Inc, OP1177ARMZ Datasheet - Page 20

• Manufacturer Part Number: OP1177ARMZ
• Description: SINGLE, PRECISION LOW NOISE OP AMP
• Manufacturer: Analog Devices Inc

Specifications of OP1177ARMZ

• Design Resources: Versatile High Precision Programmable Current Sources Using DACs, Op Amps, and MOSFET Transistors (CN0151) How to Achieve High Precision Voltage Level Setting Using AD5541A/42A (CN0169)
• Amplifier Type: General Purpose
• Number Of Circuits: 1
• Slew Rate: 0.7 V/µs
• Gain Bandwidth Product: 1.3MHz
• Current - Input Bias: 500pA
• Voltage - Input Offset: 15µV
• Current - Supply: 400µA
• Current - Output / Channel: 10mA
• Voltage - Supply, Single/dual (±): 5 V ~ 36 V, ±2.5 V ~ 18 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Output Type: -
• -3db Bandwidth: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

OP1177/OP2177/OP4177
SINGLE OPERATIONAL AMPLIFIER BRIDGE
The low input offset voltage drift of the OP1177 makes it very
effective for bridge amplifier circuits used in RTD signal condi-
tioning. It is often more economical to use a single bridge
operational amplifier as opposed to an instrumentation amplifier.
In the circuit shown in Figure 66, the output voltage at the
operational amplifier is
0.1µF
V
O
100Ω
RTD
=
ADR421
R2
+15V
R
Figure 65. Low Power Linearized RTD Circuit
⎡
⎢
⎢
⎢
⎢
⎣
V
4.12kΩ
REF
2
3
⎛
⎜
⎜
⎜
⎜
⎝
OP2177
R1
R
100Ω
1/2
8
4
V+
V–
+
⎛ +
⎜
⎝
1
100Ω
4.12kΩ
δ
R2
1
R1
20Ω
⎞
⎟
⎠
(
1
+
V
OUT
δ
4.37kΩ
)
6
5
⎞
⎟
⎟
⎟
⎟
⎠
⎤
⎥
⎥
⎥
⎥
⎦
OP2177
1/2
49.9kΩ
500Ω
200Ω
7
5kΩ
V
Rev. G | Page 20 of 24
OUT
where δ = ΔR/R is the fractional deviation of the RTD resistance
with respect to the bridge resistance due to the change in temper-
ature at the RTD.
For δ << 1, the preceding expression becomes
With V
to δ with a gain factor of
0.1µF
V
V
⎡
⎢
⎣
O
⎛
⎜
⎝
REF
REF
R2
≅
R
⎛
⎜
⎝
constant, the output voltage is linearly proportional
ADR421
⎛
⎜
⎝
⎞
⎟
⎠
R2
R2
R
⎛
⎜
⎝
R
15V
1
⎞
⎟
⎠
+
⎞
⎟
⎠
⎡
⎢
⎣
V
R2
R1
⎛ +
⎜
⎝
Figure 66. Single Bridge Amplifier
1
REF
R(1+δ)
⎞
⎟
⎠
⎛
⎜
⎜
⎜
⎜
⎝
+
R1
R2
1
R
⎛
⎜
⎝
+
R2
⎞
⎟
⎠
R1
+
R1
R
⎛
⎜
⎝
⎞
⎟
⎠
δ
⎤
⎥
⎦
R2
+
R1
R
R
V
R2
R1
REF
⎞
⎟
⎠
⎤
⎥
⎦
δ
⎞
⎟
⎟
⎟
⎟
⎠
=
2
3
OP1177
R
R
7
4
F
V+
V–
F
6
V
OUT