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Design >> Analog Design >> How to measure temperature coefficient (TC) in bandgap reference circuit?
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Message started by Bean Nakamura on Mar 27^th, 2018, 9:56pm

Title: How to measure temperature coefficient (TC) in bandgap reference circuit?
Post by Bean Nakamura on Mar 27^th, 2018, 9:56pm

Hello all,
I have simulated a simple sub 1-V bandgap circuit , the famous Banba architecture and obtained a Vref vs temperature as attached in the figure below.
I know that the shape is not concave/convex as one would typically look like but the variation is very small, ie 2mV. I have a couple of questions:-

1)How do I obtain the temperature coefficient in ppm/C of this particular bandgap circuit from the two graphs I just plotted? (Red is Vref, Yellow is derivative of Vref).

2)What does the temperature coefficient actually tell us? Is it the accuracy of the bandgap? Can't I just describe the accuracy in terms of voltage variations with respect to temperature?

3)What is a good TC value? Is a bandgap circuit with a higher TC better than one with a lower TC?

Thanks in advance!