reference voltage problem

[avinash]

I have a bangap reference voltage of 1.16V.i need a 3.5V reference voltage .how can i achieve 3.5V through 1.16V so that the 3.5V reference voltage is also temperature independent and supply independent.

 

[kenawy]

hi
the LM308 datasheet shows you how to make good refrence voltage using lm366 refrence voltage
see the datasheet

 

[IanP]

I would amplify the 1.16V from your bandgap to 3.5V using an opamp in non-inverting configuration.
Even very popular lm358 (or similar structure) should be good enough for this job..
Regards,
IanP

 

[xiongshoufen]

there is a papre about your issue in IEEE

you can find it in IEEE

the author of the papre is japanese.

 

[tsanlee]

You can design a normal bandgap (near 1.2V),and then design a X2 or X3 circuit .
the X2/X3 Circuit is temp independent circuit(use the same type resistor is necessary.

 

[jiangwp]

Maybe , a like LDO circuit is fit for you.

Only a boost power supply can be made.

If the power supply is smaller than 3.5, the charge pump is need.

 

[rogerliu]

hi, avinash

1. use doubler or tribler+OP amplifer, if VDD<3.9V
2. use op amplifer get 3.5v, if VDD≥4V

 

[electronrancher]

there is a papre about your issue in IEEE

you can find it in IEEE

the author of the papre is japanese.

IEEE, and Japanese? That narrows it down to about 50,000 papers.. hahaha!

Anyway - Yes, this is a standard requirement for internal regulator, or to use a bandgap to build an LDO. IanP had it best - A small amp drives a resistor divider, in your case you may use 11.6k on bottom, 23.4k on top. Inverting terminal of the amp connects to the center of this divider chain, while noninverting terminal connects to the reference voltage. Since the amp will ensure it's inputs are driven to equality, the top of the resistor chain will be driven to 3.5v while the center tap rises to 1.16v to equal the bandgap voltage. As for the curvature... A good amp will make sure that the 3.5v output has exactly the same percent curvature that the reference does.