How to design a CMOS level shift buffer

[kevinwang123]

I want to use the buffer to drive PMOS pass device of regulator.
does anyone know it or have papers?

Thanks a lot and best regards

 

[montage3000]

what your concrete requirement?

 

[kevinwang123]

The input voltage of buffer is equal to the output volatge of buffer.

the pass device output current is 30mA.

 

[present]

Maybe you can try to use some even number inverters.

The input voltage of buffer is equal to the output volatge of buffer.

the pass device output current is 30mA.

 

[mdcui]

here is the possible schematic

 

[qutang]

I think using a source follewer .

 

[kevinwang123]

Thank you for your suggestion!

I had used the soure follower but it can't work well

I have tried to use a unity gain buffer but the drive capability is not enough,
The load transient of the regulator is so poor because this regulator is used in internal chip for digital parts, I can't add a large capacitor in chip.

Do you have any idea or papers?

Thank you very much!

 

[pfd001]

you should pay attention to the frequence compensation

 

[johnsmith101]

you may be able to use a simple two stage amplifier. it really depends on your requirements. can you give us some more information?

 

[caosl]

The simple source follower can be used to seperate the PMOS and OTA's output.The best circuit is small output resisteance and large drive current.

 

[llc1kitty]

simply one stage op-amp is enough. But you should pay attention to AC characteristics of the regulator circuit.