What is bandgap reference generator and why do we need it in the circuit?

[VLSI_Learner]

Can you please explain it -
What is bandgap reference generator and why do we need it in the circuit?

 

[FoxyRick]

What is bandgap reference generator

As google can tell you, it is a fixed voltage reference that does not vary significantly with temperature. Usually about 1.25V.

**broken link removed**

why do we need it in the circuit?

Which circuit? Anywhere that an accurate and stable voltage (or current) reference is required.

 

[VLSI_Learner]

In short it is simply a stable voltage source that is temperature independent.
Right?

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In short it is simply a stable voltage source that is temperature independent.
Right?

 

[FoxyRick]

Yes, that's what I said. The link explains how it works if you are interested to know that.

 

[VLSI_Learner]

What is its difference with normal voltage source?
Is it only bandgap reference generator's stability and temperature independence?
And I guess bandgap reference generator is needed for critical devices, switches, and the devices which need matching. Right?

 

[FoxyRick]

Which 'normal' voltage source are you comparing with?

Have a read of this guide to selecting a voltage reference. It discusses some uses of references, and different types of reference. You should find it useful:

www.national.com/assets/en/appnotes/national_power_designer123.pdf

 

[naveensai12]

BGR are mostly built into the IC.The BGR functions in such a way that it accounts for the change in temperature of the chip and the voltage from the BGR remains constant inspite the change in temperature .Here when u tell voltage source ,do you mean external voltage source ???

 

[VLSI_Learner]

Actually I was reading Razavi's book and there I am finding some problem understanding this. Please make me understand using some examples.