Design of third-order OTA-C type filter using cadence

[jlim]

hello,
Can someone help and guide me to design third-order OTA-C type filter using cadence? the below attachment is i found from somewhere abt gm-C filter but i dont know the OTA in transistor-level simulation model...
hope anyone who have experience to design it to help me..(urgent!!!)
thanks a lot....

 

[AMS012]

Hi,
This might help you. One is the internal circuitry of an OTA. And the other is how you can build double ended ota from two single ended otas...
https://obrazki.elektroda.pl/4017910600_1361342849.png
https://obrazki.elektroda.pl/7034687300_1361342849.png

 

[jlim]

Thanks for reply my post..
But i am not really understand abt the 1st pic(https://obrazki.elektroda.pl/4017910600_1361342849.png) and 2nd pic (https://obrazki.elektroda.pl/7034687300_1361342849.png)
a) Is it tis schematic is already the 3rd-order OTA-C filter???
b) for my attachment of picture is the differential OTA, how the transistor-level model for tis OTA???

 

[LvW]

Hi jlim.
my recommendation: First try to become familiar with basics of filter topologies.
You intend to design a 3rd order filter - and at the same time, you are not yet able to recognize if a circuit diagram is a filter or an amplifier only ?

 

[jlim]

Ok..thanks for your suggestion...
do you have any recommendation or reference for this kind filter in transistor-level model??

 

[jlim]

hello,i have using cadence to design the basic OTA but i cnt get the correct ac response...
How to determine the value for Vin+,Vin- and Vbias?