Hoi Attila
I've unearthed the TAPR T2-mini.
I need to obtain an 8 pin DIP header so that I can connect pins 2 +3 on the PCB
DIP socket.
Then I can test PN etc as function of input signal level at 10MHz.
May take a week or so to arrive.
Meanwhile I have an optical interferometer to work on.
Bru
Hello,
I think that the important point about sine-to-square converter is about
how you measure the phase noise.
If you use such converter, you don't care about the signal noise when the
output is clipped. But phase noise analyzers care about that too.
That's why Linear characterized LTC6957 addit
The second LPRO circuit uses a feedback resistor across an inverter... I used
to make oscillators that way... I'm not sure how that works out for a squarer.
They call it a "self-biased" squarer.
My input gate is a 74HC86. It is normally configured as a buffer so a feedback
resistor would add
Subject: [time-nuts] sine to square wave circuits - performance data?
Wenzel says an HC device tends to work better than an AC device in squarer
applications.
My calibrator board has a place for the feedback resistor so that I can
implement the second LPRO circuit (or add hysteresis to the squarer
Am 05.10.2017 um 00:33 schrieb Bob kb8tq:
Hi
The other issue could be that no diode ever operates instantaneously ….
Bottom line is indeed that clipping in protection diodes is not a good idea.
External
diodes …. who knows ….
And when it clips, it provides a low impedance connection
between
Hi
The other issue could be that no diode ever operates instantaneously ….
Bottom line is indeed that clipping in protection diodes is not a good idea.
External
diodes …. who knows ….
Bob
> On Oct 4, 2017, at 5:33 PM, Bruce Griffiths
> wrote:
>
> Substrate currents biasing on parasitic dev
Substrate currents biasing on parasitic devices in junction isolated process?
If so, then silicon on insulator CMOS may not exhibit the effect.
Bruce
> On 05 October 2017 at 10:18 Attila Kinali wrote:
>
>
> On Thu, 5 Oct 2017 10:11:37 +1300 (NZDT)
> Bruce Griffiths wrote:
>
> > Just avoid cur
On Thu, 5 Oct 2017 10:11:37 +1300 (NZDT)
Bruce Griffiths wrote:
> Just avoid current flowing in the input protection circuitry.
>
> Once the protection circuit is activated the jitter increases significantly.
Do you know what the mechanism is, that increases jitter in this case?
On Wed, 4 Oct 2017 16:51:23 -0400
Bob kb8tq wrote:
> There is always an … except … If you do a “feedback resistor” bias,
> forget about any sort of fast gate. Bias it with two resistors on the
> input and it should be fine. If the second resistor blows your budget
> then yes, it’s a issue.
A rel
On Wed, 4 Oct 2017 15:21:45 +
Mark Sims wrote:
> My calibrator board has a place for the feedback resistor so that I can
> implement the second LPRO circuit (or add hysteresis to the squarer gate.
I am not sure whether you meant that the feedback resistor adds hysteresis
to the squarer gate
Just avoid current flowing in the input protection circuitry.
Once the protection circuit is activated the jitter increases significantly.
Bruce
>
> On 05 October 2017 at 04:21 Mark Sims wrote:
>
> Wenzel says an HC device tends to work better than an AC device in
> squarer applicati
On Wed, 4 Oct 2017 16:47:22 -0400
Bob kb8tq wrote:
> >> Driving a 5V powered CMOS gate with 5.5V p-p does a pretty good job ….
> >
> > If you have this much signal, yes. Not everyone has the luxury of an
> > steady +19dBm input signal. Part of the reason why I am looking into
> > this is because
Hi
> On Oct 4, 2017, at 11:21 AM, Mark Sims wrote:
>
> Wenzel says an HC device tends to work better than an AC device in squarer
> applications.
That’s not the case for broadband phase noise or for close in jitter. The issue
with the older
AC parts is the crummy lead frame pinout. Settin
Hi
> On Oct 4, 2017, at 12:49 PM, Attila Kinali wrote:
>
> On Wed, 4 Oct 2017 11:01:31 -0400
> Bob kb8tq wrote:
>
>> This gets into the “other side” of the whole comparator / squaring circuit
>> test process. What matters for ADEV and what matters for phase noise at
>> 100KHz offset likely are
Wenzel says an HC device tends to work better than an AC device in squarer
applications.
My calibrator board has a place for the feedback resistor so that I can
implement the second LPRO circuit (or add hysteresis to the squarer gate.
> I find it interesting that a simple 74
The inductor in the T2-Mini is nothing special.
On Oct 4, 2017, 12:57 PM, at 12:57 PM, Attila Kinali wrote:
>On Wed, 4 Oct 2017 12:02:35 +1300 (NZDT)
>Bruce Griffiths wrote:
>
>> I could measure the PN of the TAPR variant of the Wenzel circuit
>> as well as the PN of the comparator based circuit
On Wed, 4 Oct 2017 12:02:35 +1300 (NZDT)
Bruce Griffiths wrote:
> I could measure the PN of the TAPR variant of the Wenzel circuit
> as well as the PN of the comparator based circuit (with CMOS output buffer).
BTW: one thing that has been bothering me with the TAPR variant of the
Wenzel circu
On Wed, 4 Oct 2017 11:01:31 -0400
Bob kb8tq wrote:
> This gets into the “other side” of the whole comparator / squaring circuit
> test process. What matters for ADEV and what matters for phase noise at
> 100KHz offset likely are not the same thing. A lot of circuits do quite well
> inside 100 Hz,
Hi
This gets into the “other side” of the whole comparator / squaring circuit test
process.
What matters for ADEV and what matters for phase noise at 100KHz offset likely
are
not the same thing. A lot of circuits do quite well inside 100 Hz, but not so
well above
that offset.
Driving a 5V po
I am using the simplest possible sine to square wave converter on my HP5313xA
counter time interval calibrator... a capacitively coupled HCMOS gate (74HC86)
biased at VCC/2 with two 47K resistors as shown in the LPRO manual and Wenzel's
squarer page. I was not expecting anything good, but was
Moin,
Thanks everyone for the data!
On Tue, 3 Oct 2017 21:19:47 -0600
Ed Palmer wrote:
> The "LPRO User's Guide & Integration Guidelines" includes phase noise
> data for 4 different sine to square converters in Section 3.4.
>
> http://www.ko4bb.com/manuals/207.47.238.85/Datum_LPRO_Users_guid
Hoi Bruce,
Thanks for the link. That's some nice data.
On Wed, 4 Oct 2017 12:02:35 +1300 (NZDT)
Bruce Griffiths wrote:
> I have measured the PN of the LTC6957-4 at 10MHz.
>
> I could measure the PN of the TAPR variant of the Wenzel circuit as well as
> the PN of the comparator based circuit
The "LPRO User's Guide & Integration Guidelines" includes phase noise
data for 4 different sine to square converters in Section 3.4.
http://www.ko4bb.com/manuals/207.47.238.85/Datum_LPRO_Users_guide1.pdf
I used a similar circuit, but to improve performance at 2.5 MHz and 5
MHz, I used 1000 pf
> Do you recall what the amplitude of the input signal to the Wenzel shaper
> was?
>
> Since I used a 1:2 (3dB) terminated splitter for my measurements the input
> to the splitter is the same as the Timepod reference signal amplitude
>
I was using a similar setup, so the shaper input would have
John
Do you recall what the amplitude of the input signal to the Wenzel shaper was?
Since I used a 1:2 (3dB) terminated splitter for my measurements the input to
the splitter is the same as the Timepod reference signal amplitude
Bruce
> On 04 October 2017 at 14:12 John Miles wrote:
>
>
> > I
> I have measured the PN of the LTC6957-4 at 10MHz.
>
> I could measure the PN of the TAPR variant of the Wenzel circuit as well as
> the PN of the comparator based circuit (with CMOS output buffer).
>
These plots came from the Wenzel diff-amp shaper:
http://www.ke5fx.com/wenzel_resid_PN.png
htt
Hi
Things can get a bit crazy doing this:
The Collins paper pretty well shows that edge speed matters. A survey
of comparator data sheets will also suggest the same basic thing. Up to
some point (clipping maybe) increasing the levels into a chip improves things.
Not all chips will take the same
Moin,
On 10/04/2017 12:38 AM, Attila Kinali wrote:
Moin,
The last couple of days, I have been looking into sine to square
wave converters. There are a few proposed circuits[1-4] and there
is of course Collins' paper [5]. But I am unable to find actual
performance data of the different circuits.
PN measurements for LTC6957-4 here:
http://www.ko4bb.com/getsimple/index.php?id=phase-noise-and-other-measurements-with-a-timepod
NB HX2410 plot below is for a Holzworth sine to CMOS converter.
Bruce
> On 04 October 2017 at 12:02 Bruce Griffiths
> wrote:
>
>
> Attila
>
> I have mea
Attila
I have measured the PN of the LTC6957-4 at 10MHz.
I could measure the PN of the TAPR variant of the Wenzel circuit as well as the
PN of the comparator based circuit (with CMOS output buffer).
Bruce
>
> On 04 October 2017 at 11:38 Attila Kinali wrote:
>
> Moin,
>
> The
Moin,
The last couple of days, I have been looking into sine to square
wave converters. There are a few proposed circuits[1-4] and there
is of course Collins' paper [5]. But I am unable to find actual
performance data of the different circuits. Does someone have
such data and would share it with m
31 matches
Mail list logo
