Re: [time-nuts] minimalist sine to square

[Bruce Griffiths]

I wonder what the timing jitter is like.

It may be useful to measure it along with its additive PN.

Bruce

> 
> On 22 January 2018 at 07:31 Robert LaJeunesse <lajeune...@mail.com> wrote:
> 
> How about using a single 8-pin DIP IC that is under $2.50? The Microchip 
> MIC4422AYN "gate driver" takes a 3.3V signal in and produces a fast 
> rail-to-rail output swing, with a 4.5V to 18V supply range. Typical output 
> resistance is sub 1 Ohm, so not a problem driving a series back-terminated 50 
> Ohm load. Note the 4422's rise and fall times are specified with a 10,000pF 
> load, given the primarily resistive load in this case the rise and fall 
> should be sub 10 ns (per p.5 of the data sheet). But do use beefy lo-Z traces 
> and hefty broadband supply bypassing, the MIC4422 can pump up to 9A into its 
> intended load.
> 
> Bob L.
> 
> > > 
> > Sent: Saturday, January 20, 2018 at 2:43 PM
> > From: "Jerry Hancock" <je...@hanler.com>
> > To: "Discussion of precise time and frequency measurement" 
> > <time-nuts@febo.com>
> > Subject: Re: [time-nuts] minimalist sine to square
> > 
> > ...
> > 
> > Now that I had the input conditioned, I need to drive a 50ohm load 
> > with the signal coming from the PICDIV. Can someone point me at a circuit 
> > using transistors and 10V if possible?
> > 
> > I am trying to duplicate one channel of the TADD2 so I can bring 
> > 10Mhz down to 10Khz.
> > 
> > Thanks
> > 
> > Jerry
> > 
> > > 
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Re: [time-nuts] minimalist sine to square

[Robert LaJeunesse]

How about using a single 8-pin DIP IC that is under $2.50? The Microchip 
MIC4422AYN "gate driver" takes a 3.3V signal in and produces a fast 
rail-to-rail output swing, with a 4.5V to 18V supply range. Typical output 
resistance is sub 1 Ohm, so not a problem driving a series back-terminated 50 
Ohm load. Note the 4422's rise and fall times are specified with a 10,000pF 
load, given the primarily resistive load in this case the rise and fall should 
be sub 10 ns (per p.5 of the data sheet). But do use beefy lo-Z traces and 
hefty broadband supply bypassing, the MIC4422 can pump up to 9A into its 
intended load.

Bob L.

> Sent: Saturday, January 20, 2018 at 2:43 PM
> From: "Jerry Hancock" <je...@hanler.com>
> To: "Discussion of precise time and frequency measurement" 
> <time-nuts@febo.com>
> Subject: Re: [time-nuts] minimalist sine to square
>
> ...
> 
> Now that I had the input conditioned, I need to drive a 50ohm load with the 
> signal coming from the PICDIV.  Can someone point me at a circuit using 
> transistors and 10V if possible?
> 
> I am trying to duplicate one channel of the TADD2 so I can bring 10Mhz down 
> to 10Khz.
> 
> Thanks
> 
> Jerry
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Re: [time-nuts] minimalist sine to square

[Bruce Griffiths]

An npn emitter follower with collector connected to the 10V supply will produce 
a 4.2V swing in a 50 ohm load.

However it only works well if reflections from the load are small.

Otherwise, assuming that you want a 0-5V signal at the 50 ohm load  its 
possible to build a back matched driver using 3 BJTs that will switch 200mA 
into a 25 ohm load with transition times around 5ns or so. Faster transition 
times require using transistors  with ft's somewhat greater than 300MHz.

However the 10V rail current increases to 200mA when the output is 5V at the 50 
ohm load.

Bruce


> 
> On 21 January 2018 at 08:43 Jerry Hancock  wrote:
> 
> Tom might have started this as I was playing around with PICDIV and had 
> asked him the best conditioning circuit. Turned out I had all the parts to 
> copy the TADD-2 including the mini circuits transformer so that’s what I did. 
> It works well, pretty sensitive, etc. I’ve also used the bias trick with a 
> TTL or CMOS buffer when I needed to convert SPIDF signals to baseband for 
> driving an optical connection.
> 
> Now that I had the input conditioned, I need to drive a 50ohm load with 
> the signal coming from the PICDIV. Can someone point me at a circuit using 
> transistors and 10V if possible?
> 
> I am trying to duplicate one channel of the TADD2 so I can bring 10Mhz 
> down to 10Khz.
> 
> Thanks
> 
> Jerry
> 
> > > 
> > On Jan 20, 2018, at 11:21 AM, Poul-Henning Kamp 
> >  wrote:
> > 
> > 
> > In message , 
> > jimlux writes:
> > 
> > > > > 
> > > > > > > 
> > > > I played with that, I used a small transformer to 
> > > > balance the signal
> > > > and then into LVDS receiver through a voltage divider. 
> > > > Worked well,
> > > > but I didn't measure the jitter, it was just for a 
> > > > micro-controller.
> > > > 
> > > > > > > 
> > > You can also do it with capacitive dc block to one side, and 
> > > some
> > > resistors - the ap notes describe it. The receivers are a 
> > > fairly high Z
> > > input, so you pick the voltage divider resistors to make the 
> > > termination
> > > resistance right for the incoming signal.
> > > 
> > > > > 
> > Yes, but that doesn't give you galvanic isolation, which I think is 
> > almost
> > mandatory unless it is a metrology situation.
> > 
> > --
> > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
> > p...@freebsd.org | TCP/IP since RFC 956
> > FreeBSD committer | BSD since 4.3-tahoe
> > Never attribute to malice what can adequately be explained by 
> > incompetence.
> > 
> > ___
> > time-nuts mailing list -- time-nuts@febo.com
> > To unsubscribe, go to 
> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
> > 
> > > 
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Re: [time-nuts] minimalist sine to square

[Jerry Hancock]

Tom might have started this as I was playing around with PICDIV and had asked 
him the best conditioning circuit.  Turned out I had all the parts to copy the 
TADD-2 including the mini circuits transformer so that’s what I did.  It works 
well, pretty sensitive, etc.  I’ve also used the bias trick with a TTL or CMOS 
buffer when I needed to convert SPIDF signals to baseband for driving an 
optical connection.

Now that I had the input conditioned, I need to drive a 50ohm load with the 
signal coming from the PICDIV.  Can someone point me at a circuit using 
transistors and 10V if possible?

I am trying to duplicate one channel of the TADD2 so I can bring 10Mhz down to 
10Khz.

Thanks

Jerry


> On Jan 20, 2018, at 11:21 AM, Poul-Henning Kamp  wrote:
> 
> 
> In message , jimlux 
> writes:
> 
>>> I played with that, I used a small transformer to balance the signal
>>> and then into LVDS receiver through a voltage divider.  Worked well,
>>> but I didn't measure the jitter, it was just for a micro-controller.
>> 
>> You can also do it with capacitive dc block to one side, and some 
>> resistors - the ap notes describe it.  The receivers are a fairly high Z 
>> input, so you pick the voltage divider resistors to make the termination 
>> resistance right for the incoming signal.
> 
> Yes, but that doesn't give you galvanic isolation, which I think is almost
> mandatory unless it is a metrology situation.
> 
> -- 
> Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
> p...@freebsd.org | TCP/IP since RFC 956
> FreeBSD committer   | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.
> ___
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Re: [time-nuts] minimalist sine to square

[Poul-Henning Kamp]

In message , jimlux writes:

>> I played with that, I used a small transformer to balance the signal
>> and then into LVDS receiver through a voltage divider.  Worked well,
>> but I didn't measure the jitter, it was just for a micro-controller.
>
>You can also do it with capacitive dc block to one side, and some 
>resistors - the ap notes describe it.  The receivers are a fairly high Z 
>input, so you pick the voltage divider resistors to make the termination 
>resistance right for the incoming signal.

Yes, but that doesn't give you galvanic isolation, which I think is almost
mandatory unless it is a metrology situation.

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] minimalist sine to square

[Bruce Griffiths]

Yes, I was just trying to see how far the circuit could be pushed (+27dBm input 
was still OK).

With +13dBm input peak diode current without 100R and 330R resistors is about 
20mA for the 3.3V circuit with an impedance step up from 50 to 400 ohm.

My 100MHz Wenzel OCXO has an output of around +19dBm or so.

I measure the output of all my sources before I connect them.

Bruce 

> 
> On 20 January 2018 at 15:27 Bob kb8tq  wrote:
> 
> Hi
> 
> My main point is that a +22 dbm (or even 16 dbm) OCXO is a *very* rare 
> item. If your
> signal generator is set to +22 dbm … shame on you. If the part can do 
> well over +7 to
> +13 dbm, that will cover the vast majority of the 10 MHz oscillators / 
> signal sources out there.
> 
> Bob
> 
> > > 
> > On Jan 19, 2018, at 8:51 PM, Bruce Griffiths 
> >  wrote:
> > 
> > Even the modern PICs spec 50mA max input currents.
> > Simulation indicates 20mA peak diode currents without the 330 ohm 
> > resistors for a 2V pp input, even more for higher input signal levels. If 
> > one can guarantee that input is around 1V pp then the extra diodes and 
> > resistors aren't required. If its possible that an input of 16dBm or more 
> > may be used then the extra diodes and resistors are required. I simulated 
> > the circuit for inputs up to +22dBm.
> > Current flowing in the IC protection diodes can degrade the timing 
> > jitter substantially (tens of picosec for HCMOS).
> > 
> > Bruce
> > 
> > > > > 
> > > On 20 January 2018 at 14:34 Bob kb8tq  wrote:
> > > 
> > > Hi
> > > 
> > > Unless you really beat on the thing for days on end, you can 
> > > do without the 330 ohm and 100 ohm
> > > resistors (along with the two diodes). Most modern gates have 
> > > pretty robust protection diodes. The
> > > source impedance is high enough after the transform that the 
> > > available current is pretty low. On a
> > > NC7SZ125 the negative diode is rated for 50 ma max and the 
> > > positive diode is rated for 20 ma
> > > 
> > > Some math:
> > > 
> > > If the two 1K’s properly terminate the circuit, you have a 
> > > 250 ohm source. (500 ohm load and 500 ohm
> > > transformed from the sine input). A 1V overdrive (1/2 V + and 
> > > 1/2 V -) will put 2 ma into the diodes on the
> > > peaks. The more likely case is that the negative is hit a bit 
> > > harder. The bias is most likely a bit below
> > > 1/2 Vcc for best symmetry.
> > > 
> > > None of this is to say you *should* hit the diodes. No matter 
> > > what sort they are, the performance will
> > > degrade a bit when you do. How much is of course a “that 
> > > depends”. Most of us are not driving the
> > > gate with a -180 dbc/Hz source and expecting -177 out of the 
> > > gate.
> > > 
> > > Bob
> > > 
> > > > > > > 
> > > > On Jan 19, 2018, at 8:14 PM, Bruce Griffiths 
> > > >  wrote:
> > > > 
> > > > Something like the attached circuit is suitable for 
> > > > driving the MCU clock input directly.
> > > > The diodes should be schottky signal diodes like the 
> > > > 1N5711 series. The series resistors limit the diode peak current and 
> > > > the CLK input protection network current. It should work with inputs 
> > > > from 1V pp to 8Vpp. If SMT components were used it should all fit on a 
> > > > DIP compatible daughter board.
> > > > 
> > > > Bruce
> > > > 
> > > > > > > > > 
> > > > > On 20 January 2018 at 12:37 Bob kb8tq 
> > > > >  wrote:
> > > > > 
> > > > > Bob
> > > > > 
> > > > > With a 1V p-p sort of output, a simple matching 
> > > > > network will get you into the 4 to 6V p-p range.
> > > > > Drive that into a 5V compatible CMOS gate and 
> > > > > move on …. If you have a super hot output, put
> > > > > a 3 db pad on it.
> > > > > 
> > > > > Bob
> > > > > 
> > > > > > > > > > > 
> > > > > > On Jan 19, 2018, at 5:40 PM, Tom Van Baak 
> > > > > >  wrote:
> > > > > > 
> > > > > > > > > > > > > 
> > > > > > > Tom
> > > > > > > What's the input signal amplitude?
> > > > > > > What's the desired output signal (eg 
> > > > > > > 5V CMOS, 3.3V CMOS etc)?
> > > > > > > Bruce
> > > > > > > 
> > > > > > > > > > > > > 
> > > > > > It's for a typical 5 or 10 MHz OCXO / Rb / 
> > > > > > Cs with sinewave 

Re: [time-nuts] minimalist sine to square

[Bob kb8tq]

Hi

My main point is that a +22 dbm (or even 16 dbm) OCXO is a *very* rare item. If 
your 
signal generator is set to +22 dbm … shame on you. If the part can do well over 
+7 to 
+13 dbm, that will cover the vast majority of the 10 MHz oscillators / signal 
sources out there.

Bob 

> On Jan 19, 2018, at 8:51 PM, Bruce Griffiths  
> wrote:
> 
> Even the modern PICs spec 50mA max input currents.
> Simulation indicates 20mA peak diode currents without the 330 ohm resistors 
> for a 2V pp input, even more for higher input signal levels. If one can 
> guarantee that input is around 1V pp then the extra diodes and resistors 
> aren't required. If its possible that an input of 16dBm or more may be used 
> then the extra diodes and resistors are required. I simulated the circuit for 
> inputs up to +22dBm.
> Current flowing in the IC protection diodes can degrade the timing jitter 
> substantially (tens of picosec for HCMOS).
> 
> Bruce 
>> On 20 January 2018 at 14:34 Bob kb8tq  wrote:
>> 
>> 
>> Hi
>> 
>> Unless you really beat on the thing for days on end, you can do without the 
>> 330 ohm and 100 ohm
>> resistors (along with the two diodes). Most modern gates have pretty robust 
>> protection diodes. The
>> source impedance is high enough after the transform that the available 
>> current is pretty low. On a
>> NC7SZ125 the negative diode is rated for 50 ma max and the positive diode is 
>> rated for 20 ma
>> 
>> Some math:
>> 
>> If the two 1K’s properly terminate the circuit, you have a 250 ohm source. 
>> (500 ohm load and 500 ohm
>> transformed from the sine input). A 1V overdrive (1/2 V + and 1/2 V -) will 
>> put 2 ma into the diodes on the
>> peaks.  The more likely case is that the negative is hit a bit harder. The 
>> bias is most likely a bit below
>> 1/2 Vcc for best symmetry. 
>> 
>> None of this is to say you *should* hit the diodes. No matter what sort they 
>> are, the performance will 
>> degrade a bit when you do. How much is of course a “that depends”. Most of 
>> us are not driving the
>> gate with a -180 dbc/Hz source and expecting -177 out of the gate.
>> 
>> Bob
>> 
>>> On Jan 19, 2018, at 8:14 PM, Bruce Griffiths  
>>> wrote:
>>> 
>>> Something like the attached circuit is suitable for  driving the MCU clock 
>>> input directly.
>>> The diodes should be schottky signal diodes like the 1N5711 series. The 
>>> series resistors limit the diode peak current and the CLK input protection 
>>> network current. It should work with inputs from 1V pp to 8Vpp. If SMT 
>>> components were used it should all fit on a DIP compatible daughter board.
>>> 
>>> Bruce
 On 20 January 2018 at 12:37 Bob kb8tq  wrote:
 
 
 Bob
 
 With a 1V p-p sort of output, a simple matching network will get you into 
 the 4 to 6V p-p range.
 Drive that into a 5V compatible CMOS gate and move on …. If you have a 
 super hot output, put 
 a 3 db pad on it. 
 
 Bob
 
> On Jan 19, 2018, at 5:40 PM, Tom Van Baak  wrote:
> 
>> Tom
>> What's the input signal amplitude?
>> What's the desired output signal (eg 5V CMOS, 3.3V CMOS etc)?
>> Bruce
> 
> It's for a typical 5 or 10 MHz OCXO / Rb / Cs with sinewave output; say, 
> 1 Vpp. The output should be 3.3 or 5 V depending on what the MCU needs. 
> It doesn't have to have stunning performance: think breadboard, PIC, 
> Arduino sort of stuff. I was looking for something in a PDIP-8 package; 
> the same as all the picDIV or picPET chips I use. That's why older parts 
> like µA9637 / DS9637 came to mind.
> 
> /tvb
> 
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 ___
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 https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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>>> 
>> 

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Re: [time-nuts] minimalist sine to square

[Bruce Griffiths]

Even the modern PICs spec 50mA max input currents.
Simulation indicates 20mA peak diode currents without the 330 ohm resistors for 
a 2V pp input, even more for higher input signal levels. If one can guarantee 
that input is around 1V pp then the extra diodes and resistors aren't required. 
If its possible that an input of 16dBm or more may be used then the extra 
diodes and resistors are required. I simulated the circuit for inputs up to 
+22dBm.
Current flowing in the IC protection diodes can degrade the timing jitter 
substantially (tens of picosec for HCMOS).

Bruce 
> On 20 January 2018 at 14:34 Bob kb8tq  wrote:
> 
> 
> Hi
> 
> Unless you really beat on the thing for days on end, you can do without the 
> 330 ohm and 100 ohm
> resistors (along with the two diodes). Most modern gates have pretty robust 
> protection diodes. The
> source impedance is high enough after the transform that the available 
> current is pretty low. On a
> NC7SZ125 the negative diode is rated for 50 ma max and the positive diode is 
> rated for 20 ma
> 
> Some math:
> 
> If the two 1K’s properly terminate the circuit, you have a 250 ohm source. 
> (500 ohm load and 500 ohm
> transformed from the sine input). A 1V overdrive (1/2 V + and 1/2 V -) will 
> put 2 ma into the diodes on the
> peaks.  The more likely case is that the negative is hit a bit harder. The 
> bias is most likely a bit below
> 1/2 Vcc for best symmetry. 
> 
> None of this is to say you *should* hit the diodes. No matter what sort they 
> are, the performance will 
> degrade a bit when you do. How much is of course a “that depends”. Most of us 
> are not driving the
> gate with a -180 dbc/Hz source and expecting -177 out of the gate.
> 
> Bob
> 
> > On Jan 19, 2018, at 8:14 PM, Bruce Griffiths  
> > wrote:
> > 
> > Something like the attached circuit is suitable for  driving the MCU clock 
> > input directly.
> > The diodes should be schottky signal diodes like the 1N5711 series. The 
> > series resistors limit the diode peak current and the CLK input protection 
> > network current. It should work with inputs from 1V pp to 8Vpp. If SMT 
> > components were used it should all fit on a DIP compatible daughter board.
> > 
> > Bruce
> >> On 20 January 2018 at 12:37 Bob kb8tq  wrote:
> >> 
> >> 
> >> Bob
> >> 
> >> With a 1V p-p sort of output, a simple matching network will get you into 
> >> the 4 to 6V p-p range.
> >> Drive that into a 5V compatible CMOS gate and move on …. If you have a 
> >> super hot output, put 
> >> a 3 db pad on it. 
> >> 
> >> Bob
> >> 
> >>> On Jan 19, 2018, at 5:40 PM, Tom Van Baak  wrote:
> >>> 
>  Tom
>  What's the input signal amplitude?
>  What's the desired output signal (eg 5V CMOS, 3.3V CMOS etc)?
>  Bruce
> >>> 
> >>> It's for a typical 5 or 10 MHz OCXO / Rb / Cs with sinewave output; say, 
> >>> 1 Vpp. The output should be 3.3 or 5 V depending on what the MCU needs. 
> >>> It doesn't have to have stunning performance: think breadboard, PIC, 
> >>> Arduino sort of stuff. I was looking for something in a PDIP-8 package; 
> >>> the same as all the picDIV or picPET chips I use. That's why older parts 
> >>> like µA9637 / DS9637 came to mind.
> >>> 
> >>> /tvb
> >>> 
> >>> ___
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Re: [time-nuts] minimalist sine to square

[Bruce Griffiths]

That network was for a 10MHz input.

For 5MHz double the L and C values.

For 3.3V one could use a lower step up say from  50 to 400 ohms rather than 
from 50 to 800 ohms.

1uH and 150pF and change 1k6 resistors to 820R.

Swap the 5V supply for a 3.3V supply.

L and C values aren't critical 5% or somewhat looser tolerance should be 
suffice.

Bruce

> 
> On 20 January 2018 at 14:14 Bruce Griffiths  
> wrote:
> 
> Something like the attached circuit is suitable for driving the MCU clock 
> input directly.
> The diodes should be schottky signal diodes like the 1N5711 series. The 
> series resistors limit the diode peak current and the CLK input protection 
> network current. It should work with inputs from 1V pp to 8Vpp. If SMT 
> components were used it should all fit on a DIP compatible daughter board.
> 
> Bruce
> 
> > > 
> > On 20 January 2018 at 12:37 Bob kb8tq  wrote:
> > 
> > Bob
> > 
> > With a 1V p-p sort of output, a simple matching network will get 
> > you into the 4 to 6V p-p range.
> > Drive that into a 5V compatible CMOS gate and move on …. If you 
> > have a super hot output, put
> > a 3 db pad on it.
> > 
> > Bob
> > 
> > > > > 
> > > On Jan 19, 2018, at 5:40 PM, Tom Van Baak 
> > >  wrote:
> > > 
> > > > > > > 
> > > > Tom
> > > > What's the input signal amplitude?
> > > > What's the desired output signal (eg 5V CMOS, 3.3V CMOS 
> > > > etc)?
> > > > Bruce
> > > > 
> > > > > > > 
> > > It's for a typical 5 or 10 MHz OCXO / Rb / Cs with sinewave 
> > > output; say, 1 Vpp. The output should be 3.3 or 5 V depending on what the 
> > > MCU needs. It doesn't have to have stunning performance: think 
> > > breadboard, PIC, Arduino sort of stuff. I was looking for something in a 
> > > PDIP-8 package; the same as all the picDIV or picPET chips I use. That's 
> > > why older parts like µA9637 / DS9637 came to mind.
> > > 
> > > /tvb
> > > 
> > > ___
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> > > To unsubscribe, go to 
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> > > and follow the instructions there.
> > > 
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Re: [time-nuts] minimalist sine to square

[Bob kb8tq]

Hi

Unless you really beat on the thing for days on end, you can do without the 330 
ohm and 100 ohm
resistors (along with the two diodes). Most modern gates have pretty robust 
protection diodes. The
source impedance is high enough after the transform that the available current 
is pretty low. On a
NC7SZ125 the negative diode is rated for 50 ma max and the positive diode is 
rated for 20 ma

Some math:

If the two 1K’s properly terminate the circuit, you have a 250 ohm source. (500 
ohm load and 500 ohm
transformed from the sine input). A 1V overdrive (1/2 V + and 1/2 V -) will put 
2 ma into the diodes on the
peaks.  The more likely case is that the negative is hit a bit harder. The bias 
is most likely a bit below
1/2 Vcc for best symmetry. 

None of this is to say you *should* hit the diodes. No matter what sort they 
are, the performance will 
degrade a bit when you do. How much is of course a “that depends”. Most of us 
are not driving the
gate with a -180 dbc/Hz source and expecting -177 out of the gate.

Bob

> On Jan 19, 2018, at 8:14 PM, Bruce Griffiths  
> wrote:
> 
> Something like the attached circuit is suitable for  driving the MCU clock 
> input directly.
> The diodes should be schottky signal diodes like the 1N5711 series. The 
> series resistors limit the diode peak current and the CLK input protection 
> network current. It should work with inputs from 1V pp to 8Vpp. If SMT 
> components were used it should all fit on a DIP compatible daughter board.
> 
> Bruce
>> On 20 January 2018 at 12:37 Bob kb8tq  wrote:
>> 
>> 
>> Bob
>> 
>> With a 1V p-p sort of output, a simple matching network will get you into 
>> the 4 to 6V p-p range.
>> Drive that into a 5V compatible CMOS gate and move on …. If you have a super 
>> hot output, put 
>> a 3 db pad on it. 
>> 
>> Bob
>> 
>>> On Jan 19, 2018, at 5:40 PM, Tom Van Baak  wrote:
>>> 
 Tom
 What's the input signal amplitude?
 What's the desired output signal (eg 5V CMOS, 3.3V CMOS etc)?
 Bruce
>>> 
>>> It's for a typical 5 or 10 MHz OCXO / Rb / Cs with sinewave output; say, 1 
>>> Vpp. The output should be 3.3 or 5 V depending on what the MCU needs. It 
>>> doesn't have to have stunning performance: think breadboard, PIC, Arduino 
>>> sort of stuff. I was looking for something in a PDIP-8 package; the same as 
>>> all the picDIV or picPET chips I use. That's why older parts like µA9637 / 
>>> DS9637 came to mind.
>>> 
>>> /tvb
>>> 
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Re: [time-nuts] minimalist sine to square

[Bruce Griffiths]

Something like the attached circuit is suitable for  driving the MCU clock 
input directly.
The diodes should be schottky signal diodes like the 1N5711 series. The series 
resistors limit the diode peak current and the CLK input protection network 
current. It should work with inputs from 1V pp to 8Vpp. If SMT components were 
used it should all fit on a DIP compatible daughter board.

Bruce
> On 20 January 2018 at 12:37 Bob kb8tq  wrote:
> 
> 
> Bob
> 
> With a 1V p-p sort of output, a simple matching network will get you into the 
> 4 to 6V p-p range.
> Drive that into a 5V compatible CMOS gate and move on …. If you have a super 
> hot output, put 
> a 3 db pad on it. 
> 
> Bob
> 
> > On Jan 19, 2018, at 5:40 PM, Tom Van Baak  wrote:
> > 
> >> Tom
> >> What's the input signal amplitude?
> >> What's the desired output signal (eg 5V CMOS, 3.3V CMOS etc)?
> >> Bruce
> > 
> > It's for a typical 5 or 10 MHz OCXO / Rb / Cs with sinewave output; say, 1 
> > Vpp. The output should be 3.3 or 5 V depending on what the MCU needs. It 
> > doesn't have to have stunning performance: think breadboard, PIC, Arduino 
> > sort of stuff. I was looking for something in a PDIP-8 package; the same as 
> > all the picDIV or picPET chips I use. That's why older parts like µA9637 / 
> > DS9637 came to mind.
> > 
> > /tvb
> > 
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Re: [time-nuts] minimalist sine to square

[Bob kb8tq]

Bob

With a 1V p-p sort of output, a simple matching network will get you into the 4 
to 6V p-p range.
Drive that into a 5V compatible CMOS gate and move on …. If you have a super 
hot output, put 
a 3 db pad on it. 

Bob

> On Jan 19, 2018, at 5:40 PM, Tom Van Baak  wrote:
> 
>> Tom
>> What's the input signal amplitude?
>> What's the desired output signal (eg 5V CMOS, 3.3V CMOS etc)?
>> Bruce
> 
> It's for a typical 5 or 10 MHz OCXO / Rb / Cs with sinewave output; say, 1 
> Vpp. The output should be 3.3 or 5 V depending on what the MCU needs. It 
> doesn't have to have stunning performance: think breadboard, PIC, Arduino 
> sort of stuff. I was looking for something in a PDIP-8 package; the same as 
> all the picDIV or picPET chips I use. That's why older parts like µA9637 / 
> DS9637 came to mind.
> 
> /tvb
> 
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Re: [time-nuts] minimalist sine to square

[Bruce Griffiths]

A fast DIP comparator such as an LT1016 should work but it won't perform well 
without an effective ground plane.

If a CMOS gate is used then a low Q LC impedance step up network or equivalent 
will be needed to increase the signal swing at the gate input. Add a couple of 
schottky diode clamps for overvoltage clamping (internal CMOS gate clamp 
devices usually degrade performance if they conduct).


Bruce

> 
> On 20 January 2018 at 11:40 Tom Van Baak  wrote:
> 
> > > 
> > Tom
> > What's the input signal amplitude?
> > What's the desired output signal (eg 5V CMOS, 3.3V CMOS etc)?
> > Bruce
> > 
> > > 
> It's for a typical 5 or 10 MHz OCXO / Rb / Cs with sinewave output; say, 
> 1 Vpp. The output should be 3.3 or 5 V depending on what the MCU needs. It 
> doesn't have to have stunning performance: think breadboard, PIC, Arduino 
> sort of stuff. I was looking for something in a PDIP-8 package; the same as 
> all the picDIV or picPET chips I use. That's why older parts like µA9637 / 
> DS9637 came to mind.
> 
> /tvb
> 
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Re: [time-nuts] minimalist sine to square

[Bruce Griffiths]

Now, if one added an optional TTL threshold 5V CMOS single gate inverter/buffer 
to produce 5V output when required and added an SMT 5V->3.3V regulator and 
mounted it all on a small PCB with pins to make it DIP compatible that would 
meet the brief and then some.

Otherwise an SMT (not many DIP ones left) comparator mounted on a DIP/SMT 
converter board would also work albeit with a PN/jitter performance penalty.

Bruce

> On 20 January 2018 at 11:37 Gerhard Hoffmann  wrote:
> 
> 
> 
> 
> Am 19.01.2018 um 20:31 schrieb Tom Van Baak:
> > John's TADD-2-mini [1] uses the Wenzel sine-to-square converter. It 
> > performs very well but requires +10 V.
> >
> > I'm looking for a solution that works at 5 V (e.g., USB powered) and also 
> > uses fewer parts. Wenzel also mentions using a differential line receiver 
> > [2]. That would be an ideal single-chip 5 V solution for me but the two 
> > parts he mentions, MC1489 [3] and SN55182 [4], don't appear fast enough for 
> > a 10 MHz input.
> >
> > Can any of you circuit experts suggest some line receivers that would work? 
> > Maybe DS9637 [5]? This isn't for cesium work so it doesn't have to be quite 
> > as good as the TADD-2.
> < http://cds.linear.com/docs/en/datasheet/6957fb.pdf >
> < http://cds.linear.com/docs/en/design-note/dn514f.pdf >
> 
> I have used it, found no problems. It is somewhat small :-)
> 
> regards, Gerhard
> 
> 
> 
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Re: [time-nuts] minimalist sine to square

[Tom Van Baak]

> Tom
> What's the input signal amplitude?
> What's the desired output signal (eg 5V CMOS, 3.3V CMOS etc)?
> Bruce

It's for a typical 5 or 10 MHz OCXO / Rb / Cs with sinewave output; say, 1 Vpp. 
The output should be 3.3 or 5 V depending on what the MCU needs. It doesn't 
have to have stunning performance: think breadboard, PIC, Arduino sort of 
stuff. I was looking for something in a PDIP-8 package; the same as all the 
picDIV or picPET chips I use. That's why older parts like µA9637 / DS9637 came 
to mind.

/tvb

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Re: [time-nuts] minimalist sine to square

[Gerhard Hoffmann]

Am 19.01.2018 um 20:31 schrieb Tom Van Baak:

John's TADD-2-mini [1] uses the Wenzel sine-to-square converter. It performs 
very well but requires +10 V.

I'm looking for a solution that works at 5 V (e.g., USB powered) and also uses 
fewer parts. Wenzel also mentions using a differential line receiver [2]. That 
would be an ideal single-chip 5 V solution for me but the two parts he 
mentions, MC1489 [3] and SN55182 [4], don't appear fast enough for a 10 MHz 
input.

Can any of you circuit experts suggest some line receivers that would work? 
Maybe DS9637 [5]? This isn't for cesium work so it doesn't have to be quite as 
good as the TADD-2.

< http://cds.linear.com/docs/en/datasheet/6957fb.pdf >
< http://cds.linear.com/docs/en/design-note/dn514f.pdf >

I have used it, found no problems. It is somewhat small :-)

regards, Gerhard



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Re: [time-nuts] minimalist sine to square

[Bruce Griffiths]

Tom
What's the input signal amplitude?
What's the desired output signal (eg 5V CMOS, 3.3V CMOS etc)?
Bruce
> On 20 January 2018 at 08:31 Tom Van Baak  wrote:
> 
> 
> John's TADD-2-mini [1] uses the Wenzel sine-to-square converter. It performs 
> very well but requires +10 V.
> 
> I'm looking for a solution that works at 5 V (e.g., USB powered) and also 
> uses fewer parts. Wenzel also mentions using a differential line receiver 
> [2]. That would be an ideal single-chip 5 V solution for me but the two parts 
> he mentions, MC1489 [3] and SN55182 [4], don't appear fast enough for a 10 
> MHz input.
> 
> Can any of you circuit experts suggest some line receivers that would work? 
> Maybe DS9637 [5]? This isn't for cesium work so it doesn't have to be quite 
> as good as the TADD-2.
> 
> Thanks,
> /tvb
> 
> [1] http://www.tapr.org/~n8ur/T2_Mini_Manual.pdf
> [2] http://www.wenzel.com/documents/waveform.html
> [3] https://www.onsemi.com/pub/Collateral/MC1489-D.PDF
> [4] http://www.ti.com/lit/ds/slls092d/slls092d.pdf
> [5] http://www.ti.com/lit/ds/symlink/ds9637a.pdf
> 
> 
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Re: [time-nuts] minimalist sine to square

[Graham / KE9H]

SN65LVDS34D

--- Graham / KE9H

==

On Fri, Jan 19, 2018 at 3:45 PM, Vlad  wrote:

>
>
> On 2018-01-19 14:31, Tom Van Baak wrote:
>
>> John's TADD-2-mini [1] uses the Wenzel sine-to-square converter. It
>> performs very well but requires +10 V.
>>
>
>
> I am using Wenzel approach without modification to drive it from +5V. I
> didn't see any issues for my applications (usually it perform
> sine-to-square conversion from OCXO to feed MCU clock).
>
>
> --
> WBW,
>
> V.P.
>
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Re: [time-nuts] minimalist sine to square

[Vlad]

On 2018-01-19 14:31, Tom Van Baak wrote:

John's TADD-2-mini [1] uses the Wenzel sine-to-square converter. It
performs very well but requires +10 V.



I am using Wenzel approach without modification to drive it from +5V. I 
didn't see any issues for my applications (usually it perform 
sine-to-square conversion from OCXO to feed MCU clock).



--
WBW,

V.P.
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Re: [time-nuts] minimalist sine to square

[jimlux]

On 1/19/18 12:54 PM, Poul-Henning Kamp wrote:


In message <898171c2-0e9a-6a2a-dcfc-b7d893f89...@earthlink.net>, jimlux writes:


What about the plethora of LVDS receivers - they're basically a
differential input thresholder, with deliberate hysteresis, looking for
a 300 mV shift across a 100 ohm resistor.


I played with that, I used a small transformer to balance the signal
and then into LVDS receiver through a voltage divider.  Worked well,
but I didn't measure the jitter, it was just for a micro-controller.



You can also do it with capacitive dc block to one side, and some 
resistors - the ap notes describe it.  The receivers are a fairly high Z 
input, so you pick the voltage divider resistors to make the termination 
resistance right for the incoming signal.

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Re: [time-nuts] minimalist sine to square

[Poul-Henning Kamp]

In message <63ae173b-93f4-ffe4-ddf1-655761665...@earthlink.net>, jimlux writes:
>On 1/19/18 11:31 AM, Tom Van Baak wrote:

>You do want to watch the common mode voltages - some of the parts are 
>not good about having the signals swing near the rails (or beyond).

Also be aware that specs are for balanced input signals, if you tie
one of the inputs to a threshold voltage, published specs may not apply,
in particular speed.

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] minimalist sine to square

[Poul-Henning Kamp]

In message <898171c2-0e9a-6a2a-dcfc-b7d893f89...@earthlink.net>, jimlux writes:

>What about the plethora of LVDS receivers - they're basically a 
>differential input thresholder, with deliberate hysteresis, looking for 
>a 300 mV shift across a 100 ohm resistor.

I played with that, I used a small transformer to balance the signal
and then into LVDS receiver through a voltage divider.  Worked well,
but I didn't measure the jitter, it was just for a micro-controller.

-- 
Poul-Henning Kamp   | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer   | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Re: [time-nuts] minimalist sine to square

[Dana Whitlow]

Tom,

I recently built such a device using a couple of stages of a 74HC04,
with the RF input to the 1st stage AC coupled and the input biased
by a high-value (a couple of megohms) resistor feeding back from
the output of the first inverter stage to the input of that stage.  It's so
dirt simple, it's hard to beat.

I was not particularly concerned about jitter, so if you're not already
familiar enough with the circuit to know whether or not it's good
enough, it might be worth a try.  BTW, I am running at 10 MHz from
a PRS-10 Rb, and just wanted something to drive a count-down
chain. And there's always the 74AC04 if you wanted faster edges.

Dana Whitlow


On Fri, Jan 19, 2018 at 1:31 PM, Tom Van Baak  wrote:

> John's TADD-2-mini [1] uses the Wenzel sine-to-square converter. It
> performs very well but requires +10 V.
>
> I'm looking for a solution that works at 5 V (e.g., USB powered) and also
> uses fewer parts. Wenzel also mentions using a differential line receiver
> [2]. That would be an ideal single-chip 5 V solution for me but the two
> parts he mentions, MC1489 [3] and SN55182 [4], don't appear fast enough for
> a 10 MHz input.
>
> Can any of you circuit experts suggest some line receivers that would
> work? Maybe DS9637 [5]? This isn't for cesium work so it doesn't have to be
> quite as good as the TADD-2.
>
> Thanks,
> /tvb
>
> [1] http://www.tapr.org/~n8ur/T2_Mini_Manual.pdf
> [2] http://www.wenzel.com/documents/waveform.html
> [3] https://www.onsemi.com/pub/Collateral/MC1489-D.PDF
> [4] http://www.ti.com/lit/ds/slls092d/slls092d.pdf
> [5] http://www.ti.com/lit/ds/symlink/ds9637a.pdf
>
>
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Re: [time-nuts] minimalist sine to square

[jimlux]

On 1/19/18 11:31 AM, Tom Van Baak wrote:

John's TADD-2-mini [1] uses the Wenzel sine-to-square converter. It performs 
very well but requires +10 V.

I'm looking for a solution that works at 5 V (e.g., USB powered) and also uses 
fewer parts. Wenzel also mentions using a differential line receiver [2]. That 
would be an ideal single-chip 5 V solution for me but the two parts he 
mentions, MC1489 [3] and SN55182 [4], don't appear fast enough for a 10 MHz 
input.



There are tons of LVDS that run on 3.3 or 5V, Maxim, TI both have parts.

The first Maxim part google turned up with "LVDS receiver" was a quad, 
esd protected unit good to 400 MHz, 2ns prop delay, 50mV hysteresis.


You do want to watch the common mode voltages - some of the parts are 
not good about having the signals swing near the rails (or beyond).

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Re: [time-nuts] minimalist sine to square

[jimlux]

On 1/19/18 11:31 AM, Tom Van Baak wrote:

John's TADD-2-mini [1] uses the Wenzel sine-to-square converter. It performs 
very well but requires +10 V.

I'm looking for a solution that works at 5 V (e.g., USB powered) and also uses 
fewer parts. Wenzel also mentions using a differential line receiver [2]. That 
would be an ideal single-chip 5 V solution for me but the two parts he 
mentions, MC1489 [3] and SN55182 [4], don't appear fast enough for a 10 MHz 
input.

Can any of you circuit experts suggest some line receivers that would work? 
Maybe DS9637 [5]? This isn't for cesium work so it doesn't have to be quite as 
good as the TADD-2.



What about the plethora of LVDS receivers - they're basically a 
differential input thresholder, with deliberate hysteresis, looking for 
a 300 mV shift across a 100 ohm resistor.


Plenty fast (GHz)






Thanks,
/tvb

[1] http://www.tapr.org/~n8ur/T2_Mini_Manual.pdf
[2] http://www.wenzel.com/documents/waveform.html
[3] https://www.onsemi.com/pub/Collateral/MC1489-D.PDF
[4] http://www.ti.com/lit/ds/slls092d/slls092d.pdf
[5] http://www.ti.com/lit/ds/symlink/ds9637a.pdf


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