Re: [time-nuts] minimalist sine to square

t; 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@fe

Re: [time-nuts] minimalist sine to square

p 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] minima

Re: [time-nuts] minimalist sine to square

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

Re: [time-nuts] minimalist sine to square

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

Re: [time-nuts] minimalist sine to square

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

Re: [time-nuts] minimalist sine to square

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

Re: [time-nuts] minimalist sine to square

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,

Re: [time-nuts] minimalist sine to square

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

Re: [time-nuts] minimalist sine to square

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

Re: [time-nuts] minimalist sine to square

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

Re: [time-nuts] minimalist sine to square

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

Re: [time-nuts] minimalist sine to square

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: >

Re: [time-nuts] minimalist sine to square

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

Re: [time-nuts] minimalist sine to square

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

Re: [time-nuts] minimalist sine to square

> 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

Re: [time-nuts] minimalist sine to square

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

Re: [time-nuts] minimalist sine to square

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. >

Re: [time-nuts] minimalist sine to square

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

Re: [time-nuts] minimalist sine to square

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

Re: [time-nuts] minimalist sine to square

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

Re: [time-nuts] minimalist sine to square

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

Re: [time-nuts] minimalist sine to square

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

Re: [time-nuts] minimalist sine to square

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,

Re: [time-nuts] minimalist sine to square

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

Re: [time-nuts] minimalist sine to square

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