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Design >> Analog Design >> Design of third-order OTA-C type filter
https://designers-guide.org/forum/YaBB.pl?num=1361237529

Message started by Jlim on Feb 18^th, 2013, 5:32pm

Title: Design of third-order OTA-C type filter
Post by Jlim on Feb 18^th, 2013, 5:32pm

Hi,
i am going to design third-order OTA-C type filter.i doubt about whether the OTA is same with Gm or not?
Then the picture i attached show the 3rd-order Gm-C filter.Can i know that how the Gm block in CMOS transistor form?
Hope for the help...thanks

Title: Re: Design of third-order OTA-C type filter
Post by buddypoor on Feb 19^th, 2013, 12:05am

Jlim, I am not quite sure what your question really is - however, perhaps it helps that each (ideal) OTA can be considered to be a voltage-controlled current source with a transfer ratio ("gain"), which is described as transconductance gm (in A/V).

Title: Re: Design of third-order OTA-C type filter
Post by Jlim on Feb 19^th, 2013, 12:18am

i dont know how to build "gm" block that show in attachment in CMOS transistor form...Can anyone to help me?

Title: Re: Design of third-order OTA-C type filter
Post by buddypoor on Feb 19^th, 2013, 2:43am

Jlim wrote on Feb 19^th, 2013, 12:18am:

i dont know how to build "gm" block that show in attachment in CMOS transistor form...Can anyone to help me?

What means "build" ? In hardware or as a transistor-based simulation model?

Title: Re: Design of third-order OTA-C type filter
Post by Jlim on Feb 19^th, 2013, 9:00am

thanks to reply...sorry make u confusing...
i want to design Gm as a transistor-based simulation model by using cadence...do u hv any suggestion circuit for me???