a question about refence on simulation and corner

[xerxer]

corners simulation resistors

i design a bandgap reference ,my bandgap voltage output is different at different mode ,such tt ss ff fs sf,but i can trim the two resistor to regulate the output and make output meet requirments .Becuase my design need precise value ,so the struction is can't be changed .
i want to ask :
one: is it reasonable in design that bandgap has different value at differnt mode ?
two: two resistors needs be trimmed ,is it i reasonable in actual chip ?.

 

[hanson_uestc]

i think you have to modify some devices parameter to obtain the idential output voltage at different corners,you can trim resistor to regulate the voltage,but commoly triming just adjust the voltage at tt corner.

 

[allan_guo]

trimming two resistor is reasonable.the match must be good

 

[dennislau]

i design a bandgap reference ,my bandgap voltage output is different at different mode ,such tt ss ff fs sf,but i can trim the two resistor to regulate the output and make output meet requirments .Becuase my design need precise value ,so the struction is can't be changed .
i want to ask :
one: is it reasonable in design that bandgap has different value at differnt mode ?
two: two resistors needs be trimmed ,is it i reasonable in actual chip ?.

The bandgap voltage should not be too much different at different corners. I guess some of the current mirror transistors go to linear region at different corners. You need to check all the transistor region at all cases.

And, what topology are you using?