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Design >> Analog Design >> A doubt: Osc paper
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Message started by packiaraj on Sep 9^th, 2007, 10:29pm

Title: A doubt: Osc paper
Post by packiaraj on Sep 9^th, 2007, 10:29pm

The author claims in his paper below claims that the cicuit in Fig.5 on Page.4 offers Temparature independent Current.
I did not understand that circuit. Can you help me understand this?

Paper: Krishnakumar Sundaresan et al " Process and Temperature Compensation in a 7-MHz CMOS Clock Oscillator" IEEE JSSC Feb 2006

Free-Download from net : [ISCAS2003 Paper, Fig.7 on Page.3]
http://www.ece.gatech.edu/research/integrated-mems/conference%20papers/sundaresan_iscas2003.pdf

Thanks in advance,
Packiaraj.V.

Title: Re: A doubt: Osc paper
Post by vence on Mar 11^th, 2009, 11:19am

I have the same question. Can anyone help me? Thanks in advance.

Title: Re: A doubt: Osc paper
Post by Nimrod Ben-Ari on Mar 23^rd, 2009, 6:17am

Hi,
The left circuit is a PTAT current source (check any VLSI circuit book for how does it work) which generate a current that has a linear behavior with temperature. this current is then used to compensate VCTRL.

Nimrod