Attenuator circuit

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Space Varmint said:
Perhaps you missed the point of my post. That one in your link uses HUGE I mean gigantic amounts of power.
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No, it's quite low power.

Those dot matrix diplay will eat a battery in no time and a processor running 4MHz is hungry too.
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It uses a low power consumption LCD text module, and PIC's are extremely low power consumption.


You mean like the link I posted?.

But the point of the link was the front end, as an example of how it could be done even on such an ancient design.
 
Nigel Goodwin said:
No, it's quite low power.



It uses a low power consumption LCD text module, and PIC's are extremely low power consumption.



.
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Ummmm...have you ever used them? No, they are not power friendly. They got about 3 or four usually SQFP packages based on Epson dot matrix IC's. They are quite sizable even being surface mount. They use the power where as a seven segment uses practically nothing at all. A possible few microamps. Nothing significant. Would be hard to measure it's so small. Granted the dot matrix screen itself used practically no power but those are very large integration ICs as opposed to a few 4543s.

A processor even the PICs with their CMOS technology uses quite a bit more power running at 4MHz as opposed to 32KHz. Off hand and I am probably wrong but maybe not. But they probably use twice the power each time you double the frequency. If that were the case and may be, then the processor would be using 125 times as much power as needed for 32KHz. Big difference in battery consumption.
 
Space Varmint said:
Ummmm...have you ever used them?
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Yes all the time.

No, they are not power friendly. They got about 3 or four usually SQFP packages based on Epson dot matrix IC's.
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You've obviously not used them yourself?, they are based on Hitachi chips - but consumption is modest, using backlit ones uses more power for the backlight than the chips do.


I completely agree that bare LCD's use hardly any power at all - but you've also got 5 power hungry TTL chips in your circuit

Even LS TTL has many times the consumption of CMOS.


I'm not sure of the ratio, but (as with all processors) power is directly related to clock speed - but even at maximum speed power consumption of PIC's is very low, the main causes of consumption are loads been fed by the PIC. Less of a concern than LS TTl.
 
Your kidding right? I mean you got to be kidding? So what do you think is inside those, what you call Hitachi chips but I will be willing to bet you they are Epson design? Whats in them? Way more than a few CMOS chip's worth of logic. Allot more. It's the same damn thing just way way more transistors. And what do you mean I ain't used them...please.

The reason I know they use way more power is because I have used them. And it's a waste to use dot matrix for digits anyway.
 
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If I wanted to I could use a '138 decoder and some data latches to drive a 7 segment display using a processor. All you do is reverse the back plane signal from the digits.
 
Hero999 said:
My computer works at 3GHz, the CPU is CMOS based, not ECL.

Here's a paper describing a 3GHx CMOS frequency divider.
https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.12.5856&rep=rep1&type=pdf
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so your memory bus speed is 3GHz????? maybe INTERNAL to the processor for distances of up to, oh, 10 microns (I know, I exaggerate)! and at very low voltage levels to boot...

I did a 100MHz pcb motherboard layout once, and had to put the adjacent signals on different layers to keep them from interfering.

If ECL is so rare, they must have something to replace it???
 
Nigel Goodwin said:
Yes all the time.


Even LS TTL has many times the consumption of CMOS.
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somethng like 1000 times as much. I remember our first CMOS microprocessor design (yes, microP not microC)... the pullup resistors used more current than the processor itself did!!!! WoW... we were all amazed, it was 1984, of course...
 
For a 2.8Ghz prescaler for use in frequency counters etc, have a look at the MC12079



Selectable division ratios of 64, 128 and 256, so that 2.8Ghz can be divided to 50, 22 or 10Mhz to feed your low power low speed counter.
Typical current consumption 9mA at 5 volts. Does that count as being too power hungry?

I am sure there are other prescalers, this is just the first one I found.

JimB
 
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That looks like a handy part.
 

Those are horrible divisions. Is it processor? If so the guy don't know nothing about using the prescaler. Oh, I see. Sorry. It's just a prescaler. No, they have ones that divide in base ten. Might have to pre-order them. Could be a bit of a wait. Also you ever price them things? No wonder a Cray will cost you an arm and a leg. Think about how many they got in them.

But talking about the guy with the 3GHz bus for his computer...lol. He must be using fiber optics for the actual bus. I think that's what Cray's use and ECL for bus drivers and latches.
 
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Bon, did you have a look at the part I posted? It looks like it might make a good front end for a counter. Appears to work at 100MHz at 10mv input.
 
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