How to generate a "process independent" current so

[qpau]

I have a voltage signal and I want to use this voltage signal to generate a current output.
The simplest way is use V/R=I.
However, the R comes with serious variation in semiconductor process.
How can I use a known voltage signal to generate a "process independent" current output?

 

[runom]

Re: How to generate a "process independent" curren

u can go through allen hallberg's book about current reference chapter , this will give you the initial idea about process independent current source.
wish u good luck.

 

[Question]

use a resistor out of chip, it is process independent.

 

[pbs681]

Re: How to generate a "process independent" curren

I have a voltage signal and I want to use this voltage signal to generate a current output.
The simplest way is use V/R=I.
However, the R comes with serious variation in semiconductor process.
How can I use a known voltage signal to generate a "process independent" current output?

The variation is always there but you can minimise it by using proper layout technique...

 

[st01liyp]

bandgap reference may satisfy you.

 

[wonbef]

Re: How to generate a "process independent" curren

bandgap voltage reference with extenal precission resister regulation.

 

[engrvip]

ya BGR will be u seful for it.

 

[megzhuy]

I don't understand why you need this kind of current. PTAT is useful in chip.

 

[spbhu]

Re: How to generate a "process independent" curren

Use bandgap voltage across a resistor!

 

[wpchan05]

Re: How to generate a "process independent" curren

Use bandgap voltage across a resistor!

If I need a high quality current output (with large output resistance), can I just use bandgap voltage across a resistor!