OP177GPZ Analog Devices Inc, OP177GPZ Datasheet - Page 9

• Manufacturer Part Number: OP177GPZ
• Description: IC OPAMP GP PREC LN 8DIP
• Manufacturer: Analog Devices Inc

Specifications of OP177GPZ

• Slew Rate: 0.3 V/µs
• Design Resources: AD7266 SAR ADC in DC-Coupled Differential and Single-Ended Appls (CN0039) DC-Coupled, Single-Ended-to-Differential Conversion Using AD8138 and AD7352 (CN0040) DC-Coupled, Single-Ended-to-Differential Conversion Using AD8138 and AD7356 (CN0041) AD7265 in Differential and Single-Ended Configurations Using AD8022 (CN0048) Unipolar, Precision DC Digital-to-Analog Conversion using AD5450/1/2/3 8-14-Bit DACs (CN0052) DC-Coupled, Single-Ended-to-Differential Conversion Using AD8138 and AD7357 (CN0061)
• Amplifier Type: General Purpose
• Number Of Circuits: 1
• Gain Bandwidth Product: 600kHz
• Current - Input Bias: 1.2nA
• Voltage - Input Offset: 20µV
• Current - Supply: 1.6mA
• Voltage - Supply, Single/dual (±): 6 V ~ 36 V, ±3 V ~ 18 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Through Hole
• Package / Case: 8-DIP (0.300", 7.62mm)
• Op Amp Type: Precision
• No. Of Amplifiers: 1
• Bandwidth: 600kHz
• Supply Voltage Range: ± 3V To ± 18V
• Amplifier Case Style: DIP
• No. Of Pins: 8
• Common Mode Rejection Ratio: 140
• Current, Input Bias: +1.2 nA
• Current, Input Offset: 0.3 nA
• Current, Supply: 1.6 mA
• Impedance, Thermal: 43 °C/W
• Package Type: PDIP-8
• Power Dissipation: 50 mW
• Resistance, Input: 45 Megohms (Differential), 200 Gigaohms (Common-Mode)
• Temperature, Operating, Range: -40 to +85 °C
• Voltage, Gain: 6000 V/mV
• Voltage, Input: +14 V
• Voltage, Noise: 118 nV
• Voltage, Offset: 20 μV
• Voltage, Output, High: +14 V
• Voltage, Output, Low: -14 V
• Voltage, Supply: ±15 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Output Type: -
• Current - Output / Channel: -
• -3db Bandwidth: -
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

APPLICATIONS INFORMATION
GAIN LINEARITY
The actual open-loop gain of most monolithic op amps varies at
different output voltages. This nonlinearity causes errors in high
closed-loop gain circuits.
It is important to know that the manufacturer’s A
tion is only a part of the solution because all automated testers
use endpoint testing and, therefore, show only the average gain.
For example, Figure 24 shows a typical precision op amp with a
respectable open-loop gain of 650 V/mV. However, the gain is
not constant through the output voltage range, causing non-
linear errors. An ideal op amp shows a horizontal scope trace.
Figure 25 shows the OP177 output gain linearity trace with its
truly impressive average A
is virtually horizontal at all points, assuring extremely high gain
accuracy. Analog Devices also performs additional testing to
ensure consistent high open-loop gain at various output
voltages. Figure 26 is a simple open-loop gain test circuit.
A
R
V
VO
L
IN
= 2kΩ
≥ 12000V/mV
= ±10V
Figure 26. Open-Loop Gain Linearity Test Circuit
–10V
A
R
VO
L
Figure 25. Output Gain Linearity Trace
Figure 24. Typical Precision Op Amp
= 2kΩ
≥ 650V/mV
–10V
10kΩ
VO
1MΩ
10Ω
of 12,000 V/mV. The output trace
0V
V
V
0V
Y
Y
10kΩ
–
OP177
+
+10V
V
+10V
X
R
L
VO
specifica-
V
V
X
X
Rev. F | Page 9 of 16
THERMOCOUPLE AMPLIFIER WITH COLD-
JUNCTION COMPENSATION
An example of a precision circuit is a thermocouple amplifier
that must accurately amplify very low level signals without
introducing linearity and offset errors to the circuit. In this
circuit, an S-type thermocouple with a Seebeck coefficient of
10.3 μV/°C produces 10.3 mV of output voltage at a temperature
of 1000°C. The amplifier gain is set at 973.16, thus, it produces
an output voltage of 10.024 V. Extended temperature ranges
beyond 1500°C are accomplished by reducing the amplifier
gain. The circuit uses a low cost diode to sense the temperature
at the terminating junctions and, in turn, compensates for any
ambient temperature change. The OP177, with its high open-
loop gain plus low offset voltage and drift, combines to yield a
precise temperature sensing circuit. Circuit values for other
thermocouple types are listed in Table 5.
Table 5.
Thermocouple
Type
K
J
S
TYPES
+15V
Figure 27. Thermocouple Amplifier with Cold Junction Compensation
+
–
COLD-JUNCTION
COMPENSATION
ISOTHERMAL
ISOTHERMAL
2.2µF
+
JUNCTIONS
2
BLOCK
COLD-
REF01
Seebeck
Coefficient
39.2 μV/°C
50.2 μV/°C
10.3 μV/°C
4
6
COPPER
COPPER
20.5kΩ
47kΩ
100Ω
1%
1%
1%
R
R
R
3
2
1
R1
110 Ω
100 Ω
100 Ω
ADJUST-
10.000V
10µF
+
1.0kΩ
0.05%
MENT)
(ZERO
R
100Ω
8
50Ω
1%
R
R
5
4
ANALOG
GROUND
5.76 kΩ
4.02 kΩ
20.5 kΩ
R2
R
392kΩ
1%
7
10µF
OP177
–
+
+15V
–15V
R7
102 kΩ
80.6 kΩ
392 kΩ
1.07MΩ
0.05%
0.1µF
10µF
10µF
0.1µF
R
GROUND
9
ANALOG
OP177
R9
269 kΩ
200 kΩ
1.07 MΩ
V
OUT