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Design >> Analog Design >> Problems for minimum Length in Analog circuits
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Message started by vishwanath on Oct 13^th, 2004, 1:55am

Title: Problems for minimum Length in Analog circuits
Post by vishwanath on Oct 13^th, 2004, 1:55am

HI,

I designed Voltage regulator using NMOS pass transistor, Here, I used NMOS with w=5u, l=0.35u and M=6 to get low resistance. Can we use minimum length for analog circuits... if not what problems...

Regards
vishwanath

Title: Re: Problems for minimum Length in Analog circuits
Post by ywguo on Oct 13^th, 2004, 3:28am

Hello,

Why cannot you use minimum length for pass transistor. Although the minimum channel length is avoided when designing opamp, current mirror, etc., I think it is a good choice when you design a pass transistor.

We choose longer channel length for good matching, noise consideration. But for a pass transistor used in a voltage regulator, the concern is small series resistance.

Do you agree with me?

Yawei