有源滤波器

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仿真有源滤波器工艺角时发现截至频率变化很大，最大误差50%，有没有什么办法解决呢，或者怎样去进行频率补偿，用的是TSMC65nm工艺，当电阻电容都是ff类型时，误差50%

LoktikVJ

use mos as cap and add RC-calibration

CQUPT幸运

   

LoktikVJ 发表于 2022-5-10 15:08
use mos as cap and add RC-calibration

how to add RC-calibration

LoktikVJ

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LoktikVJ 发表于 2022-5-10 18:27

can you share more information,thanks vrey much

LoktikVJ

if something is not clear in picture, I can explain, I used this idea many many times and it worked great for filters. you just need to charge cap by reference current for a few cycles of ref clock and then compare Vcap to voltage drop across res Vres. when Vcap gets higher Vres it means that Tref=Cap*Res, and res mism is compensated by trim capacitance.

LoktikVJ

in not, just increase trim cap and try again

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LoktikVJ 发表于 2022-5-10 19:00
if something is not clear in picture, I can explain, I used this idea many many times and it worked  ...

如何控制电容是充电还是放电呢，图中mos管旁边的反相器作用是什么？谢谢！

LoktikVJ

added small update, check timig dig with phases, signal mode controls charge time, then switch current for Vres generation. in the end of cycle disharge cap.

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LoktikVJ 发表于 2022-5-11 15:23
added small update, check timig dig with phases, signal mode controls charge time, then switch curre ...

can you share this paper?