[SOLVED] negative miller capacitance in OTA

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muhaned

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what does the negative mean in OTA? and how can i to explain it ?

thank you
 

All transistors have Miller capacitance which is from the inverting output to the input. In a differential amp , by adding caps by cross over ( From + out to + in and -out to -in ) from internal differential outputs, it tends to cancel the negative feedback with a lesser positive feedback with non inverting current or negative Miller Effect .

When done right, with very low connection ESR you get extended bandwidth and it remains stable.
 
thank you for reply
you mean that i have to connect the output and input capacitor(miller capacitor) opposite input and output of OTA
 

muhaned said:
thank you for reply
you mean that i have to connect the output and input capacitor(miller capacitor) opposite input and output of OTA
Click to expand...

You are advised to apply this principle inside a differential output OTA, due to parasitic effects of layout and likely instabilities otherwise neglected.

Do you understand Negative Miller Effect is positive feedback?
 

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