difference between beff and betaeff in mos spectra op point

[ETR69]

Hi experts, when I select a mos transistor and print a dc operating
point from ADE L, in result display window i found beff and
betaeff.
What is the difference between beff and betaeff?
Thanks
Etr69

 

[Wanyoung Zhang]

On Wednesday, January 28, 2015 at 5:45:48 AM UTC-7, ETR69 wrote:

Hi experts, when I select a mos transistor and print a dc operating
point from ADE L, in result display window i found beff and
betaeff.
What is the difference between beff and betaeff?
Thanks
Etr69

Hi, I think betaeff = u*Cox*(W/L). beff is a parameter used in the BJT small signal model. It represents the ratio of collect current over base current. Personally, I don't think there is a beff in MOSFET small signal model.. If so, beff should be very large because the input impedance of a MOSFET is infinity. I hope this would be help. Also, please correct me if I made mistakes.

Will

 

[ETR69]

Il giorno giovedě 29 gennaio 2015 17:55:53 UTC+1, Wanyoung Zhang ha scritto:

On Wednesday, January 28, 2015 at 5:45:48 AM UTC-7, ETR69 wrote:
Hi experts, when I select a mos transistor and print a dc operating
point from ADE L, in result display window i found beff and
betaeff.
What is the difference between beff and betaeff?
Thanks
Etr69

Hi, I think betaeff = u*Cox*(W/L). beff is a parameter used in the BJT small signal model. It represents the ratio of collect current over base current. Personally, I don't think there is a beff in MOSFET small signal model. If so, beff should be very large because the input impedance of a MOSFET is infinity. I hope this would be help. Also, please correct me if I made mistakes.

Will

Hi Wanyoung, thanks for your reply. My circuit has only pmos and nmos transistors and not BJT.When Spectra calculate dc operating point, beff parameter could be u*Cox*(W/L) with mos transistor in saturation region. Is it possible ?