how to design a low voltage opa without special transisitor?

hello everyone,I need a opa ,it's voltage is 1V,how can i do it?tanghua_0407@163.com thanks!

Re: how to design a low voltage opa without special transisi

One simple way is to use voltage dubler that can work at 0.9v
look at:

https://focus.ti.com/lit/ds/symlink/tps60312.pdf

you can convert 1v to 3v

Then you can use normal opam.

Regards

Moda

1V supply opamp is not difficult. The point is what kind of specification is required. For example, input common mode range, output range, output loading, bandwidth and application.

it is used in a bandgap reference ,input common mode is about 0.6v,the vdd is from 0.8 to 4v !there are some data about the opa ,but they don't explain how to design the bias circuit ! i feel difficult to design the bias for so large range vdd!

Re: how to design a low voltage opa without special transisi

Hi, The bias op must use a current bias which is indepdent of power supply, such as PTAT or other. I think there are many biases like this.

But if you do not have a low threshold MOS transistor, i think it is difficult to design a op with power supply only 0.8v for a simple structure ,small area and power dissipation.

I think you can use the common source single transistor amplifier to replace the differential op amp to sure the same level for bandgap.

Added after 1 minutes:


Hi, The bias op must use a current bias which is indepdent of power supply, such as PTAT or other. I think there are many biases like this.

But if you do not have a low threshold MOS transistor, i think it is difficult to design a op with power supply only 0.8v for a simple structure ,small area and power dissipation.

I think you can use the common source single transistor amplifier to replace the differential op amp to sure the same level for bandgap.

try operate the transistor in the weak-inversion

it is not diffcult to realize.
please refer to P431 from: CMOS analog circuit design. Allen