about bandgap TC curve being concave instead of protruding

[wangwang96]

bandgap tc

I have designed a bandgap and sweep the temperature curve,I found the temperature curve is concave,but it should be protruding according to theory,I am confused about it ,someone can explain it for me? thanks a lot!

 

[mpig09]

tc contributions to a band gap

Dear wangwang96:

If your circuit has two res, please adjust the res you can see the curve will
change.

When you design a bandgap circuit, you need to check res, veb of TC and
the same sign TC of res.


mpig

 

[wangwang96]

tc curve

Dear wangwang96:

If your circuit has two res, please adjust the res you can see the curve will
change.

When you design a bandgap circuit, you need to check res, veb of TC and
the same sign TC of res.


mpig

Thanks mpig,I changed the resistor to ideal resistor,but the TC curve is stilll concave,I think if the BJT model has some problems?

 

[wangwang96]

tc curv

somebody can help me to solve the problem,thanks!

 

[jeffsky520]

about bandgap TC curve

I have also met the same situation, but have no idea about that even now.