Help: Generate multiple reference voltages from bandgap ref

[chemaphy]

Hello all,

I have just finished the core design of my ADC. I am now designing a circuit that generate multiple reference voltages from a bandgap reference circuit. Is there any good way to achieve that? For my circuit, I have a 3.5V power supply. The reference voltages that I need to generate is 2.2V, 1.6V 1.7V, 0.8V and 2.5V. The technology that I am using is a 0.18um SiGe BiCMOS process. Could anyone give me suggestion and topology of circuit that I can use? Thank you very much!

Regards,
chemaphy

 

[lics]

Re: Help: Generate multiple reference voltages from bandgap

Hi,
I think you can use the reference voltage generate a reference current, then use the current to make other voltages.

 

[chemaphy]

Re: Help: Generate multiple reference voltages from bandgap

I have tried the method that you have suggested, but that would affect the reference voltage of the bandgap reference. Is there any good way to generate a set of reference voltages greater than 1.205V? Thanks

 

[pixel]

Re: Help: Generate multiple reference voltages from bandgap

I have tried the method that you have suggested, but that would affect the reference voltage of the bandgap reference. Is there any good way to generate a set of reference voltages greater than 1.205V? Thanks

Non-inverting amplifiers with gain (1+R2/R1) =2.5/1.205, 2.2V/1.205, 1.6V/1.205 , 1.7V/1.205. For 0.8V you need inverting amplifier... with gain 0.8/1.205.
Of course if you need only one reference at a time you can use only one amplifier, and with apropriate switches connect resistances that defines gain.

 

[rfzheng]

zhengrufu,一种4ppm/℃曲率补偿的CMOS带隙基准源 微电子学
maybe this paper wil help you.