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MS

Mark Sims

Thu, Mar 30, 2017 8:15 PM

What did you do for input protection?

I want to build an input system for the TICC that incorporates some input protection, switchable terminator, possibly settable threshold and edge selects, and a switchable PICDIV divider like the TADD-2 Mini. That would allow inputs of <1 .. 100 (or maybe up to 1000) PPS and 1/5/10/15 MHz inputs.

The main problem I'm having is coming up with an input squarer circuit that is simple and cheap but can handle basically DC-15 MHz. Anybody got any ideas?

What did you do for input protection? I want to build an input system for the TICC that incorporates some input protection, switchable terminator, possibly settable threshold and edge selects, and a switchable PICDIV divider like the TADD-2 Mini. That would allow inputs of <1 .. 100 (or maybe up to 1000) PPS and 1/5/10/15 MHz inputs. The main problem I'm having is coming up with an input squarer circuit that is simple and cheap but can handle basically DC-15 MHz. Anybody got any ideas?

MS

Mark Sims

Fri, Mar 31, 2017 3:23 AM

(this might be a duplicate post... the last time I sent this, the message bounced)

What did you do for input protection?

I want to build an input system for the TICC that incorporates some input protection, switchable terminator, possibly settable threshold and edge selects, and a switchable PICDIV divider like the TADD-2 Mini. That would allow inputs of <1 .. 100 (or maybe up to 1000) PPS and 1/5/10/15 MHz inputs.

The main problem I'm having is coming up with an input squarer circuit that is simple and cheap but can handle basically DC-15 MHz. Anybody got any ideas?

(this might be a duplicate post... the last time I sent this, the message bounced) What did you do for input protection? I want to build an input system for the TICC that incorporates some input protection, switchable terminator, possibly settable threshold and edge selects, and a switchable PICDIV divider like the TADD-2 Mini. That would allow inputs of <1 .. 100 (or maybe up to 1000) PPS and 1/5/10/15 MHz inputs. The main problem I'm having is coming up with an input squarer circuit that is simple and cheap but can handle basically DC-15 MHz. Anybody got any ideas?

BG

Bruce Griffiths

Fri, Mar 31, 2017 3:24 AM

A single or dual supply CMOS output comparator should suffice together with some diode clamps.

Since the TICC only resolves a few tens of picosec the choice of comparator etc isnt critical.

LTC6752 (~$US2) or similar perhaps?

A single supply comparator should suffice unless you want to measure NECL or similar signals.

Bruce

 On 31 March 2017 at 09:15 Mark Sims <holrum@hotmail.com> wrote:

 What did you do for input protection?

 I want to build an input system for the TICC that incorporates some input protection, switchable terminator, possibly settable threshold and edge selects, and a switchable PICDIV divider like the TADD-2 Mini. That would allow inputs of <1 .. 100 (or maybe up to 1000) PPS and 1/5/10/15 MHz inputs.

 The main problem I'm having is coming up with an input squarer circuit that is simple and cheap but can handle basically DC-15 MHz. Anybody got any ideas?

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A single or dual supply CMOS output comparator should suffice together with some diode clamps. Since the TICC only resolves a few tens of picosec the choice of comparator etc isnt critical. LTC6752 (~$US2) or similar perhaps? A single supply comparator should suffice unless you want to measure NECL or similar signals. Bruce > > On 31 March 2017 at 09:15 Mark Sims <holrum@hotmail.com> wrote: > > What did you do for input protection? > > I want to build an input system for the TICC that incorporates some input protection, switchable terminator, possibly settable threshold and edge selects, and a switchable PICDIV divider like the TADD-2 Mini. That would allow inputs of <1 .. 100 (or maybe up to 1000) PPS and 1/5/10/15 MHz inputs. > > The main problem I'm having is coming up with an input squarer circuit that is simple and cheap but can handle basically DC-15 MHz. Anybody got any ideas? > > _______________________________________________ > 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. >

T

timeok

Fri, Mar 31, 2017 6:04 AM

As protection circuit I have used a 51ohm from the front panel input to the TICC input than two diodes one from TICC input to gnd , other from TICC input to +5V. A swichable 51ohm from front panel input to gnd allow to have 1M or 50 ohm as input impedance.
The front panel leds are drived from 2N3904 transistors connected to:
A14 for the channel A
A15 for the channel B
PPS for reference 10MHZ (close to the pic divider)
PW1 for the TX data (a 2N3906 instead 04 is used as not inverting function)
Luciano
www.timeok.it

Da "time-nuts" time-nuts-bounces@febo.com
A "time-nuts@febo.com" time-nuts@febo.com
Cc
Data Thu, 30 Mar 2017 20:15:09 +0000
Oggetto [time-nuts] TAPR TICC boxed
What did you do for input protection?

I want to build an input system for the TICC that incorporates some input protection, switchable terminator, possibly settable threshold and edge selects, and a switchable PICDIV divider like the TADD-2 Mini. That would allow inputs of <1 .. 100 (or maybe up to 1000) PPS and 1/5/10/15 MHz inputs.

The main problem I'm having is coming up with an input squarer circuit that is simple and cheap but can handle basically DC-15 MHz. Anybody got any ideas?

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.

As protection circuit I have used a 51ohm from the front panel input to the TICC input than two diodes one from TICC input to gnd , other from TICC input to +5V. A swichable 51ohm from front panel input to gnd allow to have 1M or 50 ohm as input impedance. The front panel leds are drived from 2N3904 transistors connected to: A14 for the channel A A15 for the channel B PPS for reference 10MHZ (close to the pic divider) PW1 for the TX data (a 2N3906 instead 04 is used as not inverting function) Luciano www.timeok.it Da "time-nuts" time-nuts-bounces@febo.com A "time-nuts@febo.com" time-nuts@febo.com Cc Data Thu, 30 Mar 2017 20:15:09 +0000 Oggetto [time-nuts] TAPR TICC boxed What did you do for input protection? I want to build an input system for the TICC that incorporates some input protection, switchable terminator, possibly settable threshold and edge selects, and a switchable PICDIV divider like the TADD-2 Mini. That would allow inputs of <1 .. 100 (or maybe up to 1000) PPS and 1/5/10/15 MHz inputs. The main problem I'm having is coming up with an input squarer circuit that is simple and cheap but can handle basically DC-15 MHz. Anybody got any ideas? _______________________________________________ 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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TAPR TICC boxed