what state of the mos in two stage op is correct

what state is mos

just like the topic,i want to design a op,and use hspice simulate it,but unluckiy i cant't get the desire result,i find my result in hspice' document of lis,it detail information is ,
subckt x1 x1 x1 x1 x1 x1
element 1:m1 1:m2 1:m3 1:m4 1:m5 1:m6
model 0:nch.1 0:nch.1 0ch.1 0ch.1 0:nch.1 0ch.1
region Saturati Saturati Cutoff Cutoff Linear Cutoff
id -1.580e-06 -1.580e-06 -5.245e-13 -5.245e-13 -3.954e-06 -2.603e-07
ibs 2.600e-18 2.600e-18 -1.977e-06 -1.977e-06 7.048e-18 -2.579e-05
ibd 3.971e-07 3.971e-07 -2.423e-25 -2.423e-25 9.666e-15 2.076e-16
vgs 3.142e-02 3.142e-02 0. 2.178e-13 1.083e+00 -4.573e-01
vds -4.633e-01 -4.633e-01 -7.479e-01 -7.479e-01 -3.142e-02 -1.205e+00
vbs 0. 0. -7.479e-01 -7.479e-01 0. -1.205e+00
vth 4.347e-01 4.347e-01 -6.396e-01 -6.396e-01 5.327e-01 -5.947e-01
vdsat 9.849e-02 9.849e-02 -4.587e-02 -4.587e-02 4.965e-01 -5.213e-02
vod -4.032e-01 -4.032e-01 6.396e-01 6.396e-01 5.507e-01 1.374e-01
beta 4.185e-04 4.185e-04 2.301e-04 2.301e-04 2.378e-04 1.185e-03
gam eff 4.693e-01 4.693e-01 4.056e-01 4.056e-01 4.525e-01 4.089e-01
gm 2.437e-05 2.437e-05 1.274e-11 1.274e-11 6.480e-06 4.773e-06
gds 7.796e-08 7.796e-08 6.297e-14 6.297e-14 1.220e-04 2.215e-08
gmb 4.605e-06 4.605e-06 2.359e-12 2.359e-12 2.015e-06 3.561e-07
cdtot 2.705e-14 2.705e-14 1.221e-14 1.221e-14 2.535e-14 5.860e-14
cgtot 2.245e-14 2.245e-14 6.447e-14 6.447e-14 2.485e-14 3.184e-13
cstot 6.079e-15 6.079e-15 1.634e-14 1.634e-14 2.370e-14 9.057e-14
cbtot 2.328e-14 2.328e-14 8.786e-14 8.786e-14 1.407e-14 4.419e-13
cgs 8.396e-16 8.396e-16 1.290e-15 1.290e-15 1.181e-14 6.423e-15
cgd 1.483e-14 1.483e-14 1.290e-15 1.290e-15 1.231e-14 6.423e-15



subckt x1 x1
element 1:m7 1:m8
model 0:nch.1 0:nch.1
region Linear Saturati
id -2.605e-05 3.000e-05
ibs 3.867e-17 -5.307e-17
ibd 5.495e-14 -4.041e-15
vgs 1.083e+00 1.083e+00
vds -3.748e-02 1.083e+00
vbs 0. 0.
vth 5.415e-01 5.406e-01
vdsat 4.997e-01 4.675e-01
vod 5.419e-01 5.428e-01
beta 1.333e-03 2.385e-04
gam eff 4.691e-01 4.516e-01
gm 4.241e-05 1.003e-04
gds 6.695e-04 3.926e-07
gmb 1.352e-05 2.833e-05
cdtot 1.272e-13 3.347e-15
cgtot 1.234e-13 1.822e-14
cstot 1.183e-13 2.356e-14
cbtot 6.530e-14 1.280e-14
cgs 5.981e-14 1.536e-14
cgd 6.286e-14 5.302e-16
i just want to mirrio the current of the m5 equateto m8which has 30uA ,but the result can't get it ,help ,wish veteran can solve me this qustion.

Hi chibijia,


check vgs,vds,vth,vdsat,vbs are same for both m5 and m8, if not then match them,

its very difficult to match the numbers in the snippet from *.lis file. so please attach it as a txt file so that other also can read the numbers easily.

1st thing i found was u r m5 is in linear region and m8 in saturation. which made me to believe that one of the voltages i listed above is not matching for both devices.

check it.

Hope this helps.

Thanks,

o thanks for your explation but i also have some confuse ,i just want to get 30uA current on m5,which i supply m8 with 30uA,so i set m5 and m8 the same size.my netlist is
.subckt amp vin+ vin- vo2 vdd vss
m1 3d vin+ 5d 5d nch w=4u l=2u
m2 vo1 vin- 5d 5d nch w=4u l=2u
m3 vdd 3d 3d vdd pch w=10u l=2u
m4 vdd 3d vo1 vdd pch w=10u l=2u
m5 5d vb vss vss nch w=7u l=2u
m6 vdd vo1 vo2 vdd pch w=10u l=2u m=10
m7 vo2 vb vss vss nch w=17u l=2u m=2
m8 vb vb vss vss nch w=7u l=2u
cc vo1 vo2 2.2p
cl 3 0 10p
iref vdd vb dc 30u
.ends
x1 vin+ vin- 3 vdd gnd amp
.global vdd
vdd vd 0 dc 3.3
vss vss 0 0
vin+ 1 0 dc 2
.op
.dc vin+ 0 3.3 0.01
.print dc v(3)
.probe
.lib 'mm0355v.l'tt
.options ingold=2 csdf=2
.end
i just use the tsmc' lib
and i hand calculation the kn=143u kp=62.5u
from the lib vthn=0.536 vthp=0.736
so what'wrong with my design.
help!!!

Hi,


device operation is not only depend on geometry(W & L) it also depends on terminal voltages too(vgs, vds,vbs)

in u r case vds is not matching for m5 & m8(diode connected) so u get different currents. This problem is very basic to current mirrors, please refer to literature's and books related to current mirror design.


The Vth, gama values doesn't match with the values reported in your op report for devices from Hspice.

Thanks,