The Designer's Guide Community
Forum
Welcome, Guest. Please Login or Register. Please follow the Forum guidelines.
Oct 2nd, 2024, 11:15am
Pages: 1
Send Topic Print
Multiple bandgap reference in IC (Read 2146 times)
chase.ng
Community Member
***
Offline



Posts: 77
penang/malaysia
Multiple bandgap reference in IC
Apr 09th, 2007, 5:00pm
 
Hello all,

Is it better to have only 1 centralized bandgap reference circuit and use current mirror to bias other circuits on the chip? Or is it better to have separate reference for separate circuits on the chip?

There are some arguments regarding trade-off between reliability and power. Some argue that by using multiple bandgap, I will get better reliability becuase in case one of the bandgap fail, only one part of the IC will fail.

But how often do these bandgap references fail? Anyone encounter any problem with a bandgap reference before?

Thanks and Regards,
chase.
Back to top
 
 

Chase
View Profile chase.ng   IP Logged
ywguo
Community Fellow
*****
Offline



Posts: 943
Shanghai, PRC
Re: Multiple bandgap reference in IC
Reply #1 - Apr 9th, 2007, 7:09pm
 
Hi, Chase,

I prefer a single bandgap which generate all required voltages and currents. The bandgap output is often an indication that the chip functions when we test in lab or test for mass production.

Now bandgap design is very mature and reliable. So don't worry. Furthermore, a product cannot be deliver to customers if only one part of the IC fails. So separate bandgap reference on a chip makes nonsense.


Thanks
Yawei
Back to top
 
 
View Profile   IP Logged
loose-electron
Senior Fellow
******
Offline

Best Design Tool =
Capable Designers

Posts: 1638
San Diego California
Re: Multiple bandgap reference in IC
Reply #2 - Apr 12th, 2007, 8:50pm
 
One bandgap and current distribution of bias - total agreement here.

Also Power up and power down are more predictable if it is all under the control of one bias box.

The only exception here - some RF type chips where noise in the bias distribution system is critical.

Ergo, ae you fighting thermal noise in bias currents? Hopefully not, because current source are very noisy things in the LNA-Mixer corner of the world.
Back to top
 
 

Jerry Twomey
www.effectiveelectrons.com
Read My Electronic Design Column Here
Contract IC-PCB-System Design - Analog, Mixed Signal, RF & Medical
View Profile WWW   IP Logged
Pages: 1
Send Topic Print
Copyright 2002-2024 Designer’s Guide Consulting, Inc. Designer’s Guide® is a registered trademark of Designer’s Guide Consulting, Inc. All rights reserved. Send comments or questions to editor@designers-guide.org. Consider submitting a paper or model.