Temperature dependency of Vbe of NPN transistor

[siddarth.ghaste]

Hi,

What method can be applied to reduce the temperature dependency of Vbe,so that i can have constant current in emitter. PLEASE HELP...

 

[babakta]

Hi
You can add a resistor to the emitter and for ac, bypass it with a large capacitor.

 

[siddarth.ghaste]

Resistor is already there,I also tried compensating variation of Vbe by using another transistor as voltage reference,but still it is not perfect....