short channel effect

Surely this isn't homework ?

Graham

no, imagine that i don't know. i am beginner. right, it's school project, but what's the difference?

thanks for your reply

regards

The difference is that if you're spoon-fed the answers, you don't learn anything, and school is supposed to be about learning. In the worst case, it's called "cheating", and that's what turns out incompetent graduates.

And it's generally pretty obvious whether a question is really one that a beginner has come up with on his own, or a school assignment where the beginner has no clue because he hasn't been paying attention to the background material.

Good Luck! Rich

thanks for your help and time

jutek wrote: : hello

: what should be the length of large pass device transistor to avoid short : channel effect. i am designing in 0.18um.

: regards

Not short.

If this is for your LDO regulator, why do you care about short channel effects in your output pass device? In other words: You shouldn't.

If this is for something else, and you really do care, you need to become familiar enough with your process to find the answers in the process documents/SPICE models, etc so that you can master your process, rather than let your process control your design.

Joe

Depends on what you means by short channel effect.

If you're seeking output impedance (channel-length modulation) just lengthen the channel and simulate until you get what you want.

If it's punch-through related, read the process specs.

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | |

| 1962 | Yellow Journalism has returned with a new definition... I'm afraid!

If it's exam related, read the text book.

--
  Keith