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Design >> Analog Design >> BGR convergence problem
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Message started by qiushidaren on Mar 21^st, 2012, 12:46am

Title: BGR convergence problem
Post by qiushidaren on Mar 21^st, 2012, 12:46am

Hi all,

I am simulating a bandgap, but once I put a 500k res on its output, it looks like it can't converge. Could anyone help me solve this issue?

Title: Re: BGR convergence problem
Post by loose-electron on Mar 22^nd, 2012, 11:16am

A bandgap has 2 stable operating point.

Are you familiar with the start up circuit concept?

Title: Re: BGR convergence problem
Post by RobG on Mar 23^rd, 2012, 1:53pm

Jerry brings up a good point. By not converging do you mean that the circuit simulator stops without a solution, or do you mean the circuit simulator gives a result, but the voltage at the output is not the expected ~1.2 V?

If it is the latter, then you need to check your start-up circuit.

rg

Title: Re: BGR convergence problem
Post by qiushidaren on Mar 28^th, 2012, 5:54am

RobG wrote on Mar 23^rd, 2012, 1:53pm:

I mean the simulator can't give a result, and says no convergence at -40 degree, how to solve this?

-Terry

Title: Re: BGR convergence problem
Post by RobG on Mar 28^th, 2012, 8:01am

It is going to be very difficult to help you without knowing your circuit and test bench.