Mayank
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Hi Leon, Answer to your question : Yes, if you change your DC level too quickly, it will couple and you will see a charge-sharing/feedthrough...It's categorized as a Fast transient effect...As for your query that Vin+ and Vin- are not pinning at Vdd/2, ----->
1. First of all, are you using an OTA or an opamp ? i hope you didnt mistakenly write OTA instead of opamp.... 2. In an opamp, o/p CM voltage is always of a concern in analog ckts, since it biases the next stage...So you have a CMFB Loop to control the O/p CM level....There you can use this o/p CM Level to bias the input at a fixed CM level, common for both i/p and o/p(set by CMFB Loop) On the Other Hand, In you OTA, If you have a well defined CM level(a single-ended implementation or a CMFB control in a differential one), then you can use o/p to bias i/p through a high-resistance path Mb1-2, OTHERWISE both Vin- and o/p will settle at the o/p CM level generated(which you cant be certain that it's vdd/2)
regards, Mayank.
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