#### superluminal

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**uo=350 phi=0.9 vto=0.7 mj=0.45**

Well, it was my first time trying pole zero analysis using HSPICE. then I select a very simple "academic " CMOS CS amplifier. Even I used LEVEL 1 model to make things no easier. My netlist was :

PZ trail : CS

.OPTIONS LIST NODE POST

.OP

.AC DEC 100 1K 100G

.PZ V(VOUT) VS

.PRINT AC

VDD VDD 0 DC=3V

VS VS 0 DC=0.867V AC=0.707mV

M1 VOUT VS 0 0 NMOD L=2u W=30.64u

M2 VOUT VG2 VDD VDD PMOD L=4u W=13.94u

M3 VG2 VG2 VDD VDD PMOD L=4u W=13.94u

IREF VG2 0 DC=37.65uA

.MODEL NMOD NMOS

+LEVEL=1 VTO=0.7 GAMMA=0 PHI=0.9 NSUB=9.0e+14 LD=0.08e-6 UO=350 LAMBDA=0.14 TOX=9e-9

+PB=0.9 CJ=0 CJSW=0 MJ=0.45 MJSW=0.2 CGDO=0.4e-9 CGSO=0.4e-9 JS=1e-8

.MODEL PMOD PMOS

+LEVEL=1 VTO=-0.8 GAMMA=0 PHI=0.8 NSUB=5.0e+14 LD=0.09e-6 UO=100 LAMBDA=0.07 TOX=9e-9

+PB=0.9 CJ=0 CJSW=0 MJ=0.5 MJSW=0.3 CGDO=0.3e-9 CGSO=0.3e-9 JS=0.5e-8

.ALTER

R1 VS VG1 180K

M1 VOUT VG1 0 0 NMOD L=2u W=30.64u

.END

For the first case ,R1=0, I should get only a pole at f=65.18 M & a zero at f=5.82 G (by hand).

But HSPICE gave me :

poles (rad/sec) poles ( hertz)

**********************************************************************

real imag real imag

-234.2986x 0. -37.2898x 0.

-647.3471x 0. -103.0285x 0.

zeros (rad/sec) zeros ( hertz)

**********************************************************************

real imag real imag

-386.5422x 0. -61.5201x 0.

35.5751g 0. 5.6620g 0.

& for 2nd case , I should have 2 poles : 0.89 M & 65.18 M & a zero at 5.82 G. But I got

poles (rad/sec) poles ( hertz)

**********************************************************************

real imag real imag

-5.3817x 0. -856.5288k 0.

-369.3320x 0. -58.7810x 0.

-2.6527g 0. -422.1972x 0.

zeros (rad/sec) zeros ( hertz)

**********************************************************************

real imag real imag

-386.5422x 0. -61.5201x 0.

35.5751g 0. 5.6620g 0.

Well, if you run this & see the frequency response (mag & phase) you will see only the poles and zeros you excepct by hand caculations.

If anyone can help, I will be so glad.