output stage of op for bandgap

[qslazio]

hello everyone.
Is there any need to add a source follower buffer stage as the output stage for the opamp which is used in traditional CMOS opamp based bandgap?
What's the advantage of this?
Why not just use OTA?

For stability or minimizing offset?

Thank in advance!

 

[eng_Semi]

I don't think u need to add a source follower stage, i designed it without this buffer stage. It is not needed as ur load is a capacitance (gate capacitance)

 

[pfd001]

where you find the opamp with buffer stage in bandgap?

 

[jerryzhao]

You should care the op's loading. If the loading is resistor(such as Resistor SAR ADC's reference voltage).At that time it is driver. U should use source follower as output stage or the output is current source with resistor loading.
In a word the type of OP decided by the output loading.

 

[jjsnail]

You should care the op's loading. If the loading is resistor(such as Resistor SAR ADC's reference voltage).At that time it is driver. U should use source follower as output stage or the output is current source with resistor loading.
In a word the type of OP decided by the output loading.

agree

 

[sriniv1422]

refer to brokaws paper