What is meant by rail to rail opamps?

[luckypearl25]

rail to rail opamps

what is meant by rail to rail opamps?
Is it that the input can swing from rail to rail or the o/p can go from rail to rail .Whether this rail to rail configuration is applicable in open loop or closed loop.

 

[haoyun]

rail to rail opamps

Rail to rail: from Vdd to Vss
RTR can be in input or output .

 

[ashish_chauhan]

Re: rail to rail opamps

actually if you talk about output swing there is nothing absolute rail to rail.

In case of an amplifier to be functional you need all Txs in saturation.. so you for output transistors also a difference of atleast vdsat is needed so ur output is going to be either vdd-vdsat or vss+vdsat.

 

[northeast1]

Re: rail to rail opamps

what is meant by rail to rail opamps?
Is it that the input can swing from rail to rail or the o/p can go from rail to rail .Whether this rail to rail configuration is applicable in open loop or closed loop.

rtr is vdd to vss, input can be r2r, output too, this tech is used to low voltage design

 

[rosaeidi]

rail to rail opamps

Hi

Both of input and output nodes can be r2r. Designers usually use at least two stage amplifiers in order to have r2r in i/o. Some times they use three stages: r2r input sage (for example complementary MOS), r2r output stage (for example a floating AB class) and a cascode stage between input and output stages.
Although you can merge cascode and output stages, and have two stage r2r amplifier.

 

[jeffsky520]

rail to rail opamps

Also input stage and cascode stage can be merged (such as folded cascode with complementary input pairs). Generally output stage reaches rails relatively.

 

[northeast1]

Re: rail to rail opamps

what is meant by rail to rail opamps?
Is it that the input can swing from rail to rail or the o/p can go from rail to rail .Whether this rail to rail configuration is applicable in open loop or closed loop.

rail to rail can be classed into input and output. rrio op aften used in drvier.