Pete
You can probably do much better with the AD9513 at lower frequencies if
you use a couple of cascaded longtailed pairs each with carefully
selected gain (series feedback R between the longtailed pair emitters)
and bandwidth (capacitor between the collectors) to condition the low
frequency inp
I thought I'd share some recent results for 2 useful frequency dividers.
For frequencies above 50MHz, an A-D 9513; and a 74HC4059 for
40 MHz & below. The A-D 9513 likes higher slew rates & works
best above 100MHz. I cheated and bought an evaluation board for
the A-D 9513; layout is really importa
Rich and Marcia Putz wrote:
> Hi All;
>
> All this frequency divider conjecture makes me think someone ought to come up
> with a modern design regenerative divider!
> Perhaps a double balanced mixer and a couple of high speed OP amps!
>
> Regards; Rich
> __
Hi All;
All this frequency divider conjecture makes me think someone ought to come up
with a modern design regenerative divider!
Perhaps a double balanced mixer and a couple of high speed OP amps!
Regards; Rich
___
time-nuts mailing list -- time-nuts@
Randy
In August you asked
> First off, what I am about to do is ask a REALLY STUPID question, but
> more and more of the GPS stuff I do is drifting towards the precision
> timing end of things, so I thought I should ask.
>
> I have been seeing a lot of traffic concerning making 10MHz frequency
> d
In a message dated 8/11/2006 09:57:18 Pacific Daylight Time,
[EMAIL PROTECTED] writes:
Hi Glenn, Didier,
if you plan to use an RTOS with it (many are freely available for these
chips) which really helps with house-keeping for timing applications, then I
highly recommend the Arm JTAG deb
Didier Juges wrote:
>Hi Said,
>
>Thanks for the info, I did check the Philips (and Sparkfun) web site(s)
>and I must admit the ARM chip is cheap and has impressive
>specifications. With the GNU tools, I know it will work and it will fit
>my homebrewer's budget :-) I used to consider $99 for a d
In a message dated 8/9/2006 20:29:22 Pacific Daylight Time, [EMAIL PROTECTED]
writes:
Hi Didier,
yes, its great fun to use, and much easier as well (SRAM addressing in 8051
- yuk)
BTW: I measured the 1PPS output jitter (generated by an LPC "Match" output
pin driven by an internal 60MH
> Or use 74193 synchronous counters. You will have only one gate per
> chip worth of jitter.
I think there should be only one gate of jitter per string of chips. The
whole chain is synchronous. You have to wait for the carry to settle, then
they all change on the same clock edge.
I'm assum
Hi Said,
Thanks for the info, I did check the Philips (and Sparkfun) web site(s)
and I must admit the ARM chip is cheap and has impressive
specifications. With the GNU tools, I know it will work and it will fit
my homebrewer's budget :-) I used to consider $99 for a development kit
cheap, but
Or use 74193 synchronous counters. You will have only one gate per chip
worth of jitter.
Didier
David Forbes wrote:
> At 5:31 PM -0400 8/8/06, John Ackermann N8UR wrote:
>
>> Randy Warner said the following on 08/08/2006 03:23 PM:
>>
>>
>>> I have been seeing a lot of traffic concerning
At 5:31 PM -0400 8/8/06, John Ackermann N8UR wrote:
>Randy Warner said the following on 08/08/2006 03:23 PM:
>
>> I have been seeing a lot of traffic concerning making 10MHz frequency
>> dividers using PIC's. While they provide an elegant solution to
>> providing an accurate 1PPS from a precisio
In a message dated 8/8/2006 17:21:56 Pacific Daylight Time,
[EMAIL PROTECTED] writes:
>Said,
>I understand that the micros work fine, it just seemed like you would
>need a second one to discipline the OCXO because of the timing
>constraints on the divider.
Hi Randy,
on our new GPSDO'
In a message dated 8/8/2006 19:51:06 Pacific Daylight Time, [EMAIL PROTECTED]
writes:
Hi Didier,
I used their 8051F310 in many devices, it's a great little chip :)
There are two issues that made me change to the Philips LPC2000 Arms though:
the SIL parts are somewhat expensive, and they d
I have used a number of pll controlled microcontrollers, and I would not
recommend using one of those in a timing application such as those
discussed here.
These PLLs are generally not very clean spectrally (it's actually a good
thing for EMI, some chips have purposeful spread spectrum clocks)
> I have been seeing a lot of traffic concerning making 10MHz frequency
> dividers using PIC's. While they provide an elegant solution to
> providing an accurate 1PPS from a precision source, I have to ask if
> there is a reason for going this route? I am just using three HCT40103
> down counters
Tom Van Baak wrote:
>> I understand that the micros work fine, it just seemed like you would
>> need a second one to discipline the OCXO because of the timing
>> constraints on the divider.
>
> Correct. But at $2+/- each it's easy to use one uC
> for a divider and another uC for the GPSDO algorith
ugust 08, 2006 5:39 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Frequency Dividers
> I understand that the micros work fine, it just seemed like you would
> need a second one to discipline the OCXO because of the timing
> constraints on the div
> I understand that the micros work fine, it just seemed like you would
> need a second one to discipline the OCXO because of the timing
> constraints on the divider.
Correct. But at $2+/- each it's easy to use one uC
for a divider and another uC for the GPSDO algorithm.
Yet another for an IRIG op
OTECTED]
Sent: Tuesday, August 08, 2006 5:03 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] Frequency Dividers
In a message dated 8/8/2006 14:29:38 Pacific Daylight Time,
[EMAIL PROTECTED] writes:
Hi Randy,
the Micro's allow you to do other stuff, like discipline the OCXO as
well :)
In a message dated 8/8/2006 14:29:38 Pacific Daylight Time,
[EMAIL PROTECTED] writes:
Hi Randy,
the Micro's allow you to do other stuff, like discipline the OCXO as well :)
BTW: I took a closer look at the Sparkfun board, the chip has a bunch more
Match outputs than I thought.
The Ph
ailto:[EMAIL PROTECTED] On
Behalf Of John Ackermann N8UR
Sent: Tuesday, August 08, 2006 2:31 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Frequency Dividers
Randy Warner said the following on 08/08/2006 03:23 PM:
> I have been seeing a lot of traffic concernin
From: "Tom Van Baak" <[EMAIL PROTECTED]>
Subject: Re: [time-nuts] Frequency Dividers
Date: Tue, 8 Aug 2006 14:16:24 -0700
Message-ID: <[EMAIL PROTECTED]>
> Let me add this photo - I found in a box my first attempt
> to make a PPS divider as well as an early breadb
Randy Warner said the following on 08/08/2006 03:23 PM:
> I have been seeing a lot of traffic concerning making 10MHz frequency
> dividers using PIC's. While they provide an elegant solution to
> providing an accurate 1PPS from a precision source, I have to ask if
> there is a reason for going thi
ugust 08, 2006 1:45 PM
To: time-nuts@febo.com
Subject: Re: [time-nuts] Frequency Dividers
Hi Randy,
I guess they like the intellectual challenge of tweaking PIC bits :)
There is what I think may be a better way to generate the 1PPS: you can
use an Arm micro such as the Philips LPC2102 seri
Let me add this photo - I found in a box my first attempt
to make a PPS divider as well as an early breadboard
prototype of the much simpler, PIC-based, divider.
http://www.leapsecond.com/pages/ppsdiv/ver1.jpg
/tvb
___
time-nuts mailing list
time-nut
> Hi Randy,
>
> For most purposes seven 7490's or four HC390's or
> three HCT40103, etc. will work just fine. Speaking
> for myself, the main thing was parts count. And being
> more of a software person than hardware I prefer a
> one IC solution (which has the fun of software) to
> a 3, 4, or 7 IC
o the same part and same PCB can be
used for all sorts of creative purposes.
/tvb
- Original Message -
From: "Randy Warner" <[EMAIL PROTECTED]>
To: "Discussion of precise time and frequency measurement version=3.1.0"
Sent: Tuesday, August 08, 2006 12:23
Subject
Hi Randy,
I guess they like the intellectual challenge of tweaking PIC bits :)
There is what I think may be a better way to generate the 1PPS: you can use
an Arm micro such as the Philips LPC2102 series to generate a 1PPS output
with 16.7ns settability:
these micros have counter/timers wi
Guys,
First off, what I am about to do is ask a REALLY STUPID question, but
more and more of the GPS stuff I do is drifting towards the precision
timing end of things, so I thought I should ask.
I have been seeing a lot of traffic concerning making 10MHz frequency
dividers using PIC's. While they
30 matches
Mail list logo
