Rail-to-Rail I/O Op-amps is OTA?

[firstman]

Hi,all
Rail-to-Rail I/O operational amplifiers means (OTA) operational transconductance amplifier? The main parameter of OTA is transconductance and the input and ouput resistance is very high. And Rail-to-Rail I/O op-amps? Please can anyone help me?

 

[Grossel]

Rail to rails means that inputs, output or both can handle voltages in all ranges from +V to -V (suply voltages).

 

[firstman]

thanks Grossel for your reply. But I see the papers about Rail-to-Rail I/O OTA Rail to rail operational transconductance amplifier - Patent 5208552 .

 

[audioguru]

A CA3080 eas the first transconductance amplifier IC. It is obsolete now. Then came the LM13600 then the LM13700.
They were used in the late 60's and early 70's for electric guitar effects. Nobody uses them today.

 

[crutschow]

But I see the papers about Rail-to-Rail I/O OTA Rail to rail operational transconductance amplifier - Patent 5208552 .

Just because someone has a patent, doesn't mean it's being built or used.

 

[firstman]

thanks Cruschow for your reply.

 

[dr.power]

A CA3080 eas the first transconductance amplifier IC. It is obsolete now. Then came the LM13600 then the LM13700.
They were used in the late 60's and early 70's for electric guitar effects. Nobody uses them today.

SO Do you know any new version doing the same job as CA3080? I like it as an AM modulator because of it's simplicity.

Thanks

 

[dr.power]

Does anybody knows any New version for CA3080 please?

 

[audioguru]

The very old CA3080 was a single transconductance amplifier. Today you can buy an LM13700 which is a dual transconductance amplifier that is a little different. Digikey has 243 in stock for $2.52US for the DIL package. They have 337 in a surface-mount package for $1.44US each.

 

[dr.power]

The very old CA3080 was a single transconductance amplifier. Today you can buy an LM13700 which is a dual transconductance amplifier that is a little different. Digikey has 243 in stock for $2.52US for the DIL package. They have 337 in a surface-mount package for $1.44US each.

Thanks audioguru, you are very helpful,

Is LM13700 a new transconductance amplifier? I mean is it produced widely? If not, is there any new version one?

Thanks a bunch

 

[audioguru]

The LM13700 was first produced about 39 years ago by National Semiconductor.
Today it is made by National Semi, New Japan Radio and many Chinese companies.
I don't know a newer one.

 

[dr.power]

OK, Thanks Uncle $crooge,
I will order a few of LM13700/ and CA3080 chips and work on them to see if I can get a decent AM modulation.

Thanks again & regards.