how to design a low gain and low bandwidth op?

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jfyan

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hi all,
i need an op-amp with low gain (about 10=20db) and the low dominate pole ( about 10khz), so could you suggest me some good topology or references.
thanks.
jeff
 

hi!

I think you can use single stage diferential amplifier that normally will give you ard 20 -30 dB and with only 1 dominant pole and you can adjust the pole frequency by putting capacitor at the output.
 

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    jfyan

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See fig.9.43b and 4.33 in Razavi's book
 

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    jfyan

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Bias your transistors in weak inversion and fix the gain by connecting to the output node a matched gm to increase the output conductance.
 

Does transistors in weak inversion hurt noise performance.
 

A high gain and high bandwidth opamps is hard to design. Low gain, low bandwidth one is much easier. Using capacitor to control bandwidth, transconductance (Id or/and W/L) to control gain.

jfyan said:
hi all,
i need an op-amp with low gain (about 10=20db) and the low dominate pole ( about 10khz), so could you suggest me some good topology or references.
thanks.
jeff
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