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Design >> Analog Design >> Voltage reference blocks
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Message started by baab on Dec 15^th, 2015, 6:26pm

Title: Voltage reference blocks
Post by baab on Dec 15^th, 2015, 6:26pm

Could anyone explain how these voltage reference blocks operate and how they are used in analog IC design?

Title: Re: Voltage reference blocks
Post by raja.cedt on Dec 16^th, 2015, 8:45am

Left circuit: One typical application is Vth+(N*vdsat) generation commonly used in cascade bias circuits. N in this expression can be programmed by adjusting top device size(this device will be in triode region). For simple cascode bias, we need Vth+2vdsat, for that 1/3 of the bottom device would be suffices.

Right circuit: 1. This is nothing but a diode connected transistor with less vds---if you bias the top device properly 2. Source follower with improved o/p impedance due to -ve feedback if you apply input at the top deice gate

Refer Gray and Mayer book, you will find excellent explanation of these.

Best Regards,
Raj.

Title: Re: Voltage reference blocks
Post by baab on Dec 17^th, 2015, 12:49am

Hi,
Thanks for the reply. I am trying to get a copy of the book. I will read it and ask you more after completing it.