OP290_03 Datasheet, PDF (9/12 Pages) Analog Devices – Precision, Low Power, Micropower Dual Operational Amplifier

+15V
R1
250k⍀
C1
0.1␮F
2
8
1/2
1
OP290GP
3
R2
100k⍀
OP290
The 200 Ω variable resistor is used to trim the output voltage.
For the lowest temperature drift, parallel resistors can be used in
place of the variable resistor and taken out of the circuit as required
to adjust the output voltage.
V+
D1
D2
R3
1M⍀
R4
C1
6
25k⍀ _4700pF
1/2
7
OP290GP
5
4
V_OUT
–15V
DIODES ARE 1N4148
Figure 6. Variable Slew Rate Filter
LOW OVERHEAD VOLTAGE REFERENCE
Figure 7 shows a voltage reference that requires only 0.1 V of
overhead voltage. As shown, the reference provides a stable
4.5 V output with a 4.6 V to 36 V supply. Output voltage drift is
only 12 ppm/°C. Line regulation of the reference is under 5 µV/V
with load regulation better than 10 µV/mA with up to 50 mA of
output current.
The REF-43 provides a stable 2.5 V which is multiplied by the
OP290. The PNP output transistor enables the output voltage
to approach the supply voltage.
Resistors R1 and R2 determine the output voltage.
V_OUT = 2.5V ^{}1 + ^{RR21}
2
V_IN
REF-43FZ
V_OUT ⁶
GND
4
2
8
1/2
1
OP290GP
3
4
R1B
200⍀
20-TURN
BOURNS 3006P-1-201
R1A
2.37⍀
1%
R2
2k⍀
1%
2N2907A
V_OUT
C1
10␮F
C2
0.1␮F
Figure 7. Low Overhead Voltage Reference
REV. B
–9–