Help me design a unity gain buffer

[haloo]

hi everyone.......

i was trying to design one unity gain buffer. below are the specification

unity gain

MOS transistor

TSMC 0.35µm

can anyone help me give some ideas on this unity gain circuit design? it's better to have jus around 6 MOS transistors. i'm using this unity gain in my sample and hold circuit. thank you.

 

[khouly]

unity gain buffer op

try to check analog books , this should be good task

check razavi , gray&meayer , also ken martin

khouly

 

[hung_wai_ming@hotmail.com]

design unity gain buffer

I think minimum OTA consists of 5 transistors for either PMOS load or NMOS load.
Self-biased OP-AMP should consist of 6 transistors.
However, do u need rail-to-rail input?
if yes, it's another story and you cannot achieve that.

 

[kenlino]

unity gain buffer

you can refer to

 

[haloo]

Unity gain buffer

if let's say i'm using simple OTA, there is an I Bias. what should i do when i design it? just replace a current source? or is there any way to replace the current source?

Added after 19 minutes:

if i was design my unity gain buffer using OP-amp, can anyone recommend me or show me the internal circuit of op-amp for unity gain buffer?

 

[evilguy]

Re: Unity gain buffer

is unity gain buffer is similar to voltage follower? if it is indeed similar, you can use two stage op amp and connect the output to one of it input.