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1 GHz divide-by-4

This saves a relatively expensive EclipsLite flipflop. The delay line could be a squiggly pcb trace... it's not super critical.

Version 4 SHEET 1 880 680 WIRE 64 -32 -80 -32 WIRE 256 -32 160 -32 WIRE 416 -32 336 -32 WIRE 64 0 32 0 WIRE 192 0 160 0 WIRE 32 32 32 0 WIRE 192 32 192 0 WIRE -80 160 -80 -32 WIRE 32 160 -80 160 WIRE 176 160 32 160 WIRE 32 208 -80 208 WIRE 176 208 32 208 WIRE 416 208 416 -32 WIRE 416 208 352 208 WIRE 464 208 416 208 WIRE 480 208 464 208 WIRE -80 240 -80 208 WIRE -80 368 -80 320 FLAG -80 368 0 FLAG 32 32 0 FLAG 192 32 0 FLAG 464 208 OUT FLAG 32 208 CLK FLAG 32 160 D SYMBOL Digital\\dflop 256 112 R0 WINDOW 0 -13 -35 Left 2 SYMATTR InstName A1 SYMATTR SpiceLine Td=300p SYMBOL voltage -80 224 R0 WINDOW 0 52 70 Left 2 WINDOW 3 24 119 Left 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V1 SYMATTR Value PULSE(0 1 0 100p 100p 400p 1n) SYMBOL tline 112 -16 R0 WINDOW 0 2 -80 Bottom 2 WINDOW 3 4 -66 Top 2 SYMATTR InstName T1 SYMATTR Value Td=1.2n Z0=50 SYMBOL res 352 -48 R90 WINDOW 0 -40 56 VBottom 2 WINDOW 3 -35 56 VTop 2 SYMATTR InstName R1 SYMATTR Value 50 TEXT 478 337 Left 2 !.tran 20n TEXT 472 24 Left 2 ;1 GHz Divide by 4 TEXT 456 64 Left 2 ;J Larkin Dec 17, 2014

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John Larkin         Highland Technology, Inc 
picosecond timing   laser drivers and controllers 

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com
Reply to
John Larkin
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Check out the cool waveforms on the two ends of T1.

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John Larkin Highland Technology, Inc picosecond timing laser drivers and controllers

jlarkin att highlandtechnology dott com

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Reply to
John Larkin

John Larkin:

I use a UBP1505 (from ebay of course) 3$

What are all those funny numbers you posted??

Reply to
Jan Panteltje

The schematic as LTSpice I assume.

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Dipl.-Inform(FH) Peter Heitzer, peter.heitzer@rz.uni-regensburg.de 
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Reply to
Peter Heitzer

RF stuff! It won't divide by 4, and has no reset input, and has no prop delay spec. I's probably a ripple counter with tons of delay and a bad tempco on that delay.

And NEC keeps discontinuing things.

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John Larkin         Highland Technology, Inc 
picosecond timing   laser drivers and controllers 

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com
Reply to
John Larkin

John Larkin:

Na, for div by 64 you get 6 flops for 3$ or you can tune to the 21th harmonic with a simple LC and a 30 cent transistor.

This one's been around a while, use it as prescaler in frequency counter. It is not inherently stable though, it will self-oscillate without input. So it is usable as synchronizer too :-)

Reply to
Jan Panteltje

Let it oscillate and count the output frequency. That would make a nice temperature transducer.

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John Larkin         Highland Technology, Inc 
picosecond timing   laser drivers and controllers 

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com
Reply to
John Larkin

John Larkin:

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Reply to
Jan Panteltje

Yup, CMOS has a terrible delay tempco. There's probably a diffused resistor or something involved in there, too.

Lots of uPs and FPGAs how have some sort of on-purpose, on-chip temp sensor.

I was just studying someone's timing product. It must have 20 CMOS tiny-logic chip delays from input to output, figure 10ish ps/K delay tempco each. I sure hope they temperature compensate some of that!

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John Larkin         Highland Technology, Inc 
picosecond timing   laser drivers and controllers 

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com
Reply to
John Larkin

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