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Design >> Analog Design >> Bandgap design
https://designers-guide.org/forum/YaBB.pl?num=1629135502

Message started by rajasekhar on Aug 16^th, 2021, 10:38am

Title: Bandgap design
Post by rajasekhar on Aug 16^th, 2021, 10:38am

Dear All-
I haven't seen any bandgap design with npn devices, through they are available in the kit? At least in TSMC i have seen both npn and pnp but every one (including me) designed with pnp itself? Their Beta values are very similar even. Can any one please share your experience or please point me a reference.

Thanks,
Raj.

Title: Re: Bandgap design
Post by aznsj on Nov 24^th, 2021, 10:50am

NPN needs deep-nwell process usually is expensive. so from cost point of view it is not used very often. :)

Title: Re: Bandgap design
Post by dnw on Nov 26^th, 2021, 8:54pm

I think this is a good reference

https://www.youtube.com/watch?v=CG7rTigfPYE

Title: Re: Bandgap design
Post by Horror Vacui on Mar 14^th, 2022, 7:45am

You have to use, what is available on the technology you use. CMOS technologies rarely have optimized diodes, or BJTs. These devices are formed by process steps required for CMOS transistor formation, and they are optimized for MOS transistors. One can say that the BJTs in a CMOS process are often parasitic devices. As /aznsj said, PNPs are usually better suited in a general CMOS process.