OP497 Datasheet, PDF (10/12 Pages) Analog Devices – Precision Picoampere Input Current Quad Operational Amplifier

OP497
OP497 SPICE MACRO-MODEL
Figure 12 and Table I show the node and net list for a SPICE
macro-model of the OP497. The model is a simplified version of
the actual device and simulates important dc parameters such as
V_OS, I_OS, I_B, A_VO, CMR, V_O, and I_SY. AC parameters such as slew
rate, gain and phase response, and CMR change with frequency
are also simulated by the model.
The model uses typical parameters for the OP497. The poles and
zeros in the model were determined from the actual open and
closed-loop gain and phase response of the OP497. In this way,
the model presents an accurate ac representation of the actual
device. The model assumes an ambient temperature of 25°C.
2 ^RIN2
8
–IN
C_IN
R_IN1
+IN
1
I_OS
7
CCM
99
R3
R4
C2
5
6
R1
D1
R2
–+
E_OS
CNZ
Q1 Q2
10
11
D2
R5
R6
9
I₁
50
V1 ؎
13
D3
12
G1 R7
C3
98
؎ E_REF
D4
14
V2 ؎
RCM1
15
16 17
RNZ1
18
ECM ؎ RCM2
ENZ ؎ RNZ2 G2
19
R10
C5 _G2
20
R15 C5
98
99
R16
I_SY
21
20
R17
D9
D7
D8
25 26
G4
G5
G6 _R18
D5 ₂₃ ^V3
22
24
–+
L1 _VO
27
D6
V4
R19
D10
G7
50
Figure 12. OP497 Macro Model
–10–
REV. D