OPAMP MACRO MODEL, SINGLE-POLE 
* connections:      non-inverting input    gnd
*                   |   inverting input    |    vcc 
*                   |   |   output         |    |
*                   |   |   |              |    |
.SUBCKT OPAMP1      1   2   6              20   40
*3	4
* INPUT IMPEDANCE
RIN     1       2       10MEG
* DC GAIN=100K AND POLE1=100HZ
* gain, centralise and clamp
rclah	40	30	10k
rclal	30	20	10k
ecent	31	30	1 2	 30k
.model diode d
vclamph	40	39	1.5
vclampl 21	20	1.5
dclamph	31	39	diode
dclampl 21	31	diode

* first pole: UNITY GAIN = DCGAIN X POLE1 = 10MHZ
epole   3 0    31 0     1
RP1     3       4       10
CP1     4       0       1.5915UF
* OUTPUT BUFFER AND RESISTANCE
EBUFFER 5 0     4 0	1
ROUT    5       6       10
.ENDS