How to increase PSRR value in bandgap?

[keoiuser]

hi,
in a bandgap design i have a PSRR of -50db at 1KHz, how can i increase this value? and is it important to have a big value of PSRR in a bandgap?

thanks.

 

[shringos]

PSRR in Bandgap

i think it s better to have a good PSRR esp for a bandgap since it will be used as a source. The BG that i designed has 70dB rejection till 200KHz though i dint do anything in specific to improve it.

 

[ljy4468]

PSRR in Bandgap

Use different topology.
In case of using opamp, better PSRR can be obtained, i think. Especially high gain amplifier.

 

[keoiuser]

Re: PSRR in Bandgap

thank you for replying,
Please could give an example of Amp structure (PMOS or NMOS differential pair, Folded structure of loading the amp...?)

 

[ljy4468]

PSRR in Bandgap

If you use CMOS process,
you can use conventional BGR like attached figure.

when gain of OPAMP becomes higher, you can get higher PSRR.
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Regards

 

[iscmos]

Re: PSRR in Bandgap

Could anyone tell me why this structure has a higher PSRR and the difference between this structure and traditional structure?

 

[q0w1e2r3]

Re: PSRR in Bandgap

use a high dc gain of opamp , PSRR in BG is an important issue

 

[keoiuser]

Re: PSRR in Bandgap

thank you all for your help,

when i increase PSRR to 71db at 1KHz, the value at 100K & 1M decrease (20db) and actually i had to have a good PSRR until 1MHz. what can i do?
Please help..