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Design >> Analog Design >> a input rail-to-rail opamp design
https://designers-guide.org/forum/YaBB.pl?num=1289824340

Message started by Stone.M on Nov 15^th, 2010, 4:32am

Title: a input rail-to-rail opamp design
Post by Stone.M on Nov 15^th, 2010, 4:32am

Hi guys,

I need to design a input rail-to-rail opamp, here is the spec:
1.Rail-to-Rail Input and Output;
2.Gain Bandwidth Product: 1.2MHz
3.7.5mV Typical VOS
4.Operates on 2.0 V to 5.5 V Supplies
5.Input Voltage Range: -0.1 V to +5.6 V with VCC = 5.5 V
6.Low Supply Current: 50μA

Can anyone pls give me some advice or some references? Thank you.

Regards

Title: Re: a input rail-to-rail opamp design
Post by ontheverge on Nov 16^th, 2010, 4:38am

technology?

Title: Re: a input rail-to-rail opamp design
Post by raja.cedt on Nov 16^th, 2010, 5:14am

hi,
you have huge supply man, so start with folded cascode with nmos and pmos input stages and proceed, if you need constant gm across full Input common mode range then go for complicated circuits. You can simple circuit for the specs in razaavi it self.

Thanks.

Title: Re: a input rail-to-rail opamp design
Post by loose-electron on Nov 22^nd, 2010, 2:15pm

How about starting with a little academic research first?

No offense, but you need to open both textbooks and IEEE JSSC papers, rather than just throwing it at a forum and letting someone else do the work.

Title: Re: a input rail-to-rail opamp design
Post by mowiehowie on Dec 13^th, 2010, 8:54am

theres a technique called "rail-to-rail input stage with complementary differential pairs". check it out.