Why Gray & Meyer or Razavi don't use the term OTA?

• Dec 25, 2006

• #1

J

Jim cage

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Hi,

Why isnt Gray&Meyer book and Razavi book doesnt mention anything about OTA?

I Know OTA is an Op-amp without buffer at the output, but for some reason Razavi and Grey&Meyer doesnt mention the term "OTA" in their books. Does anyone know the reason?

Regards,

 

• Dec 25, 2006

• #2

R

renwl

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cmos ota

I think you should ask Razavi and Grey&Meyer.

 

• Dec 25, 2006

• #3

J

Jim cage

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layout ota

Well.....you are not getting any points for helping

 

• Dec 25, 2006

• #4

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dongtcry

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what is ota op amp

of course they talk mostly about OTA in their books.

 

• Dec 25, 2006

• #5

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MikeR

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last year papers of ota

If you interested, you can download this paper: Design and Layout of a Telescopic Operational Transconductance Amplifier

 

• Dec 26, 2006

• #6

J

Jim cage

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op amp and ota

But the Word OTA or Transconductance isnt mentioned in their books. See the appendix yourself

 

• Dec 26, 2006

• #7

Y

ynhe

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ota and opamp

Free download from here:
**broken link removed**

ynhe

 

• Dec 26, 2006

• #8

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pk3316

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opamp ota

check ieee papers

 

• Dec 27, 2006

• #9

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liuyonggen_1

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mccarthy_548.pdf

OTA is only a kind of amplifier.

gray's book first talk about amplifer with small capacitive load, then, in another charpter, he introduced some output stage structrues for large capacitive load.

 

• Jan 7, 2007

• #10

O

OEIC

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OTA

Opamp = OTA + buffer in EE214 Class notes

 

• Jan 7, 2007

• #11

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MikeR

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OTA

Number papers for full OTA design

 

• Jan 11, 2007

• #12

J

Jim cage

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Re: OTA

In Jake baker's book he mentiones that:

"OTA is an amplifier where all nodes are low impedance exept the input and output nodes".

The Attached file for example, is not an OTA (even though it's an op-amp without buffer stage) since the M4 transistor has high Impedance node.

Does anyone here have some comment regarding this?

 

• Jan 11, 2007

• #13

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bbbb

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OTA

The main different between OTA and opamp is in output impedance since OTA is basically a voltage controlled current source. so it has a large output resistance.

Today it seems that many writers do not distinguish between OTA and OPAMP. The reason, i think, is the wide spread of CMOS circuits where a low impedance opamp (e.g. a low impeance output buffer like in 741) is seldem required.