[time-nuts] 10 MHz -> 16 MHz clock multiplier

[Max]

Where can one get some of these mythical  74HC90 's and 74AC90 's that 
have been mentioned.
  None of the usual places have them, ie ebay, digi-key, farnell, or 
even the Chinese.
  Also data-sheets are not to be found.
Thanks



On 4/01/2013 5:13 AM, Bill Fuqua wrote:
>     One way is to divide by  10 and then multiply by 16.
> Divide by 10 and then follow by 4 tuned frequency doublers.
> This should introduce little phase noise.
>     Another way to do it is to divide by 10, then pass the output thru a
> narrow 16 MHz filter and amplify. Sounds difficult but the filter can 
> be one
> or two 16 MHz crystals followed by a simple amplifier. Look at the
> reference input circuit for a PTS-160.  The output of the divide by 10 
> needs to
> be asymmetrical so it produces even harmonics. If you are using a
> divide divide by 5&2 such as a 74HC90, divide by 2 first then by 5.
>  Ideally the pulse width should be a half period of 16 MHz for the 
> maximum harmonic content at 16 MHz.
>     You can take the output of the frequency divider and send it to a 
> NAND gate.
> One input of the gate is directly connected and the other is delayed. 
> You can
> use an RC with a variable capacitor to ground to get it just right.
>     Just adjust the capacitor to get the maximum output from your
> filter amplifier.
> 73
> Bill wa4lav
>
>
>
> At 07:41 PM 1/2/2013 +0000, you wrote:
>> What's the simplest way to generate 16 MHz from 10 MHz? This will be 
>> for clocking a microcontroller at 16 MHz given 10 MHz (Cs/Rb/GPSDO). 
>> Low price and low parts count is a goal; jitter is not a concern but 
>> absolute long-term phase coherence is a must.
>>
>> The ICS525 (as in TAPR Clock-Block) is a good candidate but I was 
>> wondering if there's something cheaper, less functional, and maybe 
>> not SSOP. Any suggestions?
>>
>> Thanks,
>> /tvb
>
>
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