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Faisal Community Member Offline Posts: 90	3 phase non-overlapping clock phase generation Oct 02^nd, 2006, 2:43am Hi, I am looking for some references for 3 phase non-overlapping clock phase generation. Faisal
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ywguo Community Fellow Offline Posts: 943 Shanghai, PRC	Re: 3 phase non-overlapping clock phase generation Reply #1 - Oct 2^nd, 2006, 8:29am Hi Faisal, Are the 3 phases equal? If so, I think a DLL is required. Yawei
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Faisal Community Member Offline Posts: 90	Re: 3 phase non-overlapping clock phase generation Reply #2 - Oct 2^nd, 2006, 11:24am Hi. The two phases are equal in time. The third phase is much smaller than the two phases. Faisal
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ywguo

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Shanghai, PRC

Re: 3 phase non-overlapping clock phase generation
Reply #3 - Oct 3^rd, 2006, 6:59am

Hi Faisal,

If the third phase is much smaller than the others, it can be achieved by increaseing the delay of both paths. Then get two small phases in the nonoverlapping time of a convetional non-overlapping clock generator. En, it becomes a 4 phase clock. Sad

However, if the timing budget is not very tight, you just omit one of the small phases.

Best regards,
Yawei

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Faisal Community Member Offline Posts: 90	Re: 3 phase non-overlapping clock phase generation Reply #4 - Oct 3^rd, 2006, 12:40pm Hi Yawei, Thanks for the reply. Any ideas on the delay element/line implementation. I do not like using inverter as a delay element. I am looking for a design, which gives me more control on the delay, could be voltage controlled/ digital controlled. Papers/Reference ?? Faisal
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ywguo Community Fellow Offline Posts: 943 Shanghai, PRC	Re: 3 phase non-overlapping clock phase generation Reply #5 - Oct 5^th, 2006, 9:08am Faisal, I don't like using inverter as a delay element, too. However, it is easy. Sure you could use something voltage/digital controlled if you need a precise third phase. There are many papers/reference about delay cell design. Yawei
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loose-electron Senior Fellow Offline Best Design Tool = Capable Designers Posts: 1638 San Diego California	Re: 3 phase non-overlapping clock phase generation Reply #6 - Oct 6^th, 2006, 3:23pm take a look in the IEEE JSSC on the subject of VCO's that use Ring Oscillators. The delay element there are applicible here. Jerry
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Andrew Beckett

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Re: 3 phase non-overlapping clock phase generation
Reply #7 - Oct 28^th, 2006, 7:33am

I've done this kind of thing in the past by using a chain of inverters with the "supply" of the inverters controlled by a regulator. This regulated supply is then controlled to ensure that the chain of inverters represents once cycle of the clock - in other words, a delay locked loop, as has been suggested before.

Not sure why you object to using inverters for this - it's simple, and works...

Regards,

Andrew.

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Andrew Beckett Senior Fellow Offline Life, don't talk to me about Life... Posts: 1742 Bracknell, UK	Re: 3 phase non-overlapping clock phase generation Reply #8 - Oct 28^th, 2006, 7:35am Of course, if you have a higher frequency clock, you can divide it to obtain your different phases... and then use conventional small delays to provide the non-overlap. Regards, Andrew.
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