variable reference voltage

[bharadwaj.cv]

I want to generate a variable reference voltage. It should be such that the user can choose the input value(since my circuit is meant to be a product). This can be done by a knob or a keypad and the voltage should remain at the value he wants, till he wants. How do I do this.

One option is a potentiometer, but is this used in chip design? I can also think of the use of a microcontroller, but can this also be used in ASIC design or is there an alternate way on-chip(i am using 0.18um CMOS process)?, because on-chip options are preferred

thanks in advance

 

[kak111]

You should ask digital potentiometer from
Austriamicrosystems , Maxim , Analog Devices , Intersil , etc.......

or use an extra D/A for reference

or look this idea............

CMOS IC Makes Low-Cost Digital Potentiometer


austriamicrosystems ASIC products - analog and mixed signal ASIC experts

-look their rotary encoders too , for the "digital" knob

KAK

 

[leo_o2]

Digital programmable or analog programmable?
Digital programmable variable voltage reference should be easy to implement.
Just use resistor divider and switches.