Hi,

I have a common source amp, with a pmos diode load. According to analysis zero should be at gm of input_transistor/cgd of input_transistor.

If cgd=cgdo*w; where cgdo=3.1500E-10  (from model file) and w=1u, cgd = 0.315 fF and if gm=97.7e-6, Zero should at 310.19 G rad/sec

But the star-hspice pz analysis shows a zero at 45.7 G rad/sec.  I am not able to figure out the reason behind this difference. Can anybody please helpme with this.


Thanks and Regards
ram