OP77_15 Datasheet, PDF (14/16 Pages) Analog Devices – Next Generation OP07 Ultralow Offset Voltage Operational Amplifier

OP77
C_C
R_S
1kΩ
V_TH
R1
2kΩ
V_IN
+15V
0.1µF
R_F
100kΩ
2
7
OP77 ⁶
3
4
0.1µF
D1
1N4148
V_OUT
–15V
Figure 36. Precision Threshold Detector/Amplifier
When VIN < VTH, amplifier output swings negative, reversing the
biasing diode D1. VO = VTH if RL= ∞ when VIN > VTH, the loop
closes,
( ) V_O
= V_TH
+
V_IN
− V_TH
⎜⎜⎝⎛^{1 +}
R_F
R_S
⎟⎟⎠⎞
CC is selected to smooth the response of the loop.
+15V
0.1µF
2
V_IN
6
V_O
5
TRIM
REF-02
3
TEMP
GND
4
R_a
50kΩ
1.5kΩ
R_c
R_b1 OP77
0.1µF
R_bp
–15V
V_OUT
Figure 37. Precision Temperature Sensor
Table 8. Resistor Values
TCVOUT Slope (S)
10 mV/°C
Temperature Range −55°C to
+125°C
Output Voltage
Range
−0.55 V to
+1.25 V
Zero-Scale
0 V @ 0°C
Ra (±1% Resistor)
9.09 kΩ
Rb1 (±1% Resistor) 1.5 kΩ
Rbp (Potentiometer) 200 Ω
Rc (±1% Resistor)
5.11 kΩ
100 mV/°C
−55°C to
+125°C
−5.5 V to
+12.5V
0 V @ 0°C
15 kΩ
1.82 kΩ
500 Ω
84.5 kΩ
10 mV/°F
−67°F to
+257°C
−0.67 V to
+2.57V
0 V @ 0°F
7.5 kΩ
1.21 kΩ
200 Ω
8.25 kΩ
7
V+
R2A¹
R1A
(OPTIONAL
NULL)
1
8
R2B¹
C1
R1B
Q7
Q8
Q5
Q3 Q6
NONINVERTING ^{3 R3}
INPUT
Q1
Q21 Q23
INVERTING ^{2 R4 Q22 Q24}
INPUT
Q9
Q10
Q11 Q12
Q4
Q27 ^C3
C2
Q17
Q26 ^R5
Q25
Q2
Q14
4
Q13
V–
1_{R2A AND R2B ARE ELECTRONICALLY ADJUSTED ON CHIP AT FACTORY.}
Figure 38. Simplified Schematic
R7
Q19
R9
Q16
R10
Q20
Q15
Q18
6
OUTPUT
R6 R8
Rev. E | Page 14 of 16