OP77_02 Datasheet, PDF (14/16 Pages) Analog Devices – Next Generation OP07 Ultralow Offset Voltage Operational Amplifier

OP77
C_C
+15V
0.1␮F
R_F
100k⍀
V_TH
R_S
2
1k⍀
7
D1
6 ^1N4148
OP77
R1
3
V_IN
2k⍀
4
0.1␮F
V_OUT
–15V
Figure 17. Precision Threshold Detector/Amplifier
When V_IN < V_TH, amplifier output swings negative, reverse
biasing diode D1. V_OUT = V_TH if R_L= • when V_IN > V_TH, the
loop closes,
( ) ^VOUT ^{= V}TH ^{+ V}IN ^{– V}TH
ÊËÁ_{1 +}
R_F
R_S
ˆ¯˜
C_C is selected to smooth the response of the loop.
+15V
0.1␮F
2
V_IN
V_O
6
TRIM ⁵
REF-02
3
TEMP
GND
4
R_A
50k⍀
1.5k⍀
R_C
R_b1 OP77
0.1␮F
R_bp
–15V
V_OUT
Figure 18. Precision Temperature Sensor
Table II. Resistor Values
TCV_OUT SLOPE (S) 10 mV/∞C 100 mV/∞C 10 mV/∞F
TEMPERATURE
RANGE
–55∞C to –55∞C to –67∞F to
+125∞C +125∞C +257∞C
OUTPUT VOLTAGE –0.55 V to –5.5 V to –0.67 V to
RANGE
+1.25 V +12.5V +2.57V
ZERO-SCALE
0 V @ 0∞C 0 V @ 0∞C 0 V @ 0ЊF
R_a (± 1% Resistor)
9.09 kW 15 kW
7.5 kW
R_b1 (± 1% Resistor)
1.5 kW
1.82 kW 1.21 kW
R_bp (Potentiometer) 200 W
500 W
200 W
R_c (± 1% Resistor)
5.11 kW 84.5 kW 8.25 kW
–14–
REV. C