[SOLVED] problems Pierce Oscillator design with IC 6.1.5 using gpdk045 nm

Status
Not open for further replies.

Onyema Emmanuel

Newbie level 2
Joined
May 23, 2014
Messages
2
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Visit site
Activity points
19
Hi all,
i have designed a 920 MHz pierce oscillator using 1v vdd transistors included the 45 nm cadence gpdk045 tech. library . During the schematic simulations phase everything works fine. I did the layout and after post layout simulation using the extracted circuit, my circuit wont oscillate. to try to solve this problem, i added the total parasitics (decoupling capacitances only) on each net/node on the extracted circuit to the original schematic. Adjust circuit design to get it oscillating again. I also fingered all wide transistors. I reduced the length of interconnects. i used higher metal layers for interconnects during new layout design. I ran new post layout simulations using the newly extracted circuit. this time i get a tiny damped oscillation. Now my problem is i don't want to continue in this loop for ever as i have limited time before i tape out my design. I'm calling on all experience analog circuit designers to help me. how to i reduce the effects of parasitics? i haven't accounted for resistances and maybe that is the problem am having. how do i added this to my original schematics so that i would have compensated for all parasitics? or is there another and better way to do this in the design?
 

i solved this problem!! Don't hesitate to contact me if you run into same analog design issues.
 

Hi... eager to hear out your solution. How did you manage to solve it...
 

Status
Not open for further replies.
Cookies are required to use this site. You must accept them to continue using the site. Learn more…