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Just my personal reference page.
These fast clocks fall into 3 groups:
* combined pulse sources, which offer precision but tend to be fiddly to set up. 5 sources is probably the least fiddly.
* EC-specific, which may produce the fastest possible clock for any given simulation speed: 555; Counter-CMOS
* Semi-realistic; a very compact one is included here: L-C-NOT
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@ combined pulse sources
5 stacked pulse sources:
* 5.25 x 4x4 component size (inc. ground)
* 5x max freq
* round number adjustments
* output as crisp as you'd like
4 'trains' + XOR:
* 4.5 x 4x4 component size [+ ground]
* 4x max freq
* output not so crisp. conflict between gate delay option and simulation speed.
'trains' + resistors:
* quick setup, just set delay
* logic levels weak, but edges crisp if not driving a funny load. it's good enough for counter with 3 sources, but with 4 sources it may require some thought.
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@ EC-specific
counter-cmos:
-- credit: @nikisali
* fastest any sim speed can deal with, perhaps limited by the fets.
* for a speed limit, add a resistor between A and the FET gates. it works with the gate capacitance.
555-based:
-- credit: @hurz
* only 2 components!
* seems to be fastest any sim speed can deal with
* slows the simulation down -- hence the switch
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@ semi-realistic
l-c-invert:
* the smallest, 3.25 component size
* evidently not too limited by gate delay
* to start and run as a fastclock (faster than the simulator comfortably supports), it requires large inductor. replacing the ground with a logic source may allow manual start while keeping it very small
All these together slow down the simulator noticeably on my tablet, although I don't recall any one of them doing so alone, except the 555.
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