saad
Advanced Member level 4
Hi Everyone!!!
I am using pMOS input differential pair in a single stage opamp. I want to increase the transconductance (gm) of the input pair. I increase aspect ratio (W/L) to decrease Vdsat; hence expecting gm to increase.
On the other hand; Vds drop is decreased whereas Vdsat and gm remain almost unaffected (simulation results are given below). How can I keep Vds constant or increase gm instead? Can anyone help?
W/L = 60
Name: m1
Model: cmosp
Id: -9.90e-05
Vgs: -9.39e-01
Vds: -5.28e-02
Vbs: 0.00e+00
Vth: -5.07e-01
Vdsat: -3.59e-01
Gm: 2.15e-04
Gds: 1.73e-03
Gmb 8.41e-05
W/L=120
Name: m1
Model: cmosp
Id: -9.95e-05
Vgs: -9.14e-01
Vds: -2.70e-02
Vbs: 0.00e+00
Vth: -5.08e-01
Vdsat: -3.44e-01
Gm: 2.25e-04
Gds: 3.54e-03
Regards,
Saad
I am using pMOS input differential pair in a single stage opamp. I want to increase the transconductance (gm) of the input pair. I increase aspect ratio (W/L) to decrease Vdsat; hence expecting gm to increase.
On the other hand; Vds drop is decreased whereas Vdsat and gm remain almost unaffected (simulation results are given below). How can I keep Vds constant or increase gm instead? Can anyone help?
W/L = 60
Name: m1
Model: cmosp
Id: -9.90e-05
Vgs: -9.39e-01
Vds: -5.28e-02
Vbs: 0.00e+00
Vth: -5.07e-01
Vdsat: -3.59e-01
Gm: 2.15e-04
Gds: 1.73e-03
Gmb 8.41e-05
W/L=120
Name: m1
Model: cmosp
Id: -9.95e-05
Vgs: -9.14e-01
Vds: -2.70e-02
Vbs: 0.00e+00
Vth: -5.08e-01
Vdsat: -3.44e-01
Gm: 2.25e-04
Gds: 3.54e-03
Regards,
Saad