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Looking for >5V pretty fast logic

Hi

I am using a CD4093 with 4 schmitt triggers wired as a free running oscillator supplied by 10V. The CD4093 is 4000 series CMOS logic, but it is just too slow for my application (need a 3MHz oscillator/VCO). I can live with trigger level that has high tolerance and would shift the frequency since the loop is closed to form a VCO

So been looking at the 74HC and other series, but cannot find anything that can handle more than 6V and that is fast

Do any of you guys know of a chip? Or perhaps a faster VCO than the CD4046 PLL. Alternatively building a astable oscillator with 2 MOSFETs. Maybe even a 74HC 5V IC, but with a simple levelshift to get a fast 10V output

Regards

Klaus

Reply to
Klaus Kragelund
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Why not use HC to get the speed you need and then a fast-ish
comparator to do the level conversion?
Reply to
John Fields

Good suggestion. The problem is I need it to have low current consumption and that is difficult to find when it needs to be fast also (

Reply to
Klaus Kragelund

The 'HEF' Cmos (eg HEF4093) is twice as fast as the normal stuff.

Reply to
john jardine

Klaus, check out this one:

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John Larkin had recently used it in a switcher. Unfortunately it's around $0.50. Other than the CD4000 series there isn't much anymore that could run at high voltages. 74HC is usually rated up to 6V.

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Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg

Joerg, Nice part! You really ought to find some clientele who can afford 50¢ ;-)

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
         America: Land of the Free, Because of the Brave
Reply to
Jim Thompson

Oh, they all could. But it doesn't always make sense since many designs are very high volume. Right now I am "discretizing" an IC design because the trusty old parts might go unobtanium soon and nearly all the newfangled chips that could replace it are north of two bucks. Heck, we can get a good bottle of Merlot for that. Ok, I know you don't like the Shaw brand ;-)

BTW, for the record, it wasn't me but it was John who brought this part to our attention a few months ago.

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Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg

Good ol' Upchuck ;-)

Here's my latest favorite Chardonnay... Kim Crawford "unoaked"... $13

Thanks, John! I need such parts to convince clients to stick with a cheap low-voltage process for the main chip and use interface-specific parts at the loads.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
         America: Land of the Free, Because of the Brave
Reply to
Jim Thompson

Our favorite winery is this one:

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Had a Sangiovese yesterday, bottled it ourselves back then. That was a lot of fun. Unfortunately Ed (seen in the picture) has passed away :-(

That was not what National's marketeers intended the part to do ;-)

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Regards, Joerg

http://www.analogconsultants.com/
Reply to
Joerg

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