Can I get away with terminating the far end of a transmission line or
do I need a series resistor at the source and a parallel resistor at
the destination?
Thank you,
Toaster
Can I get away with terminating the far end of a transmission line or
do I need a series resistor at the source and a parallel resistor at
the destination?
Thank you,
Toaster
Thank you for the advice. In my case I have a 10Mhz signal with very
sharp transitions (500ps, 5V) and wanted to make sure I did things
properly.
Thank you for the advice. In my case I have a 10Mhz signal with very
sharp transitions (500ps, 5V) and wanted to make sure I did things
properly.
On Mon, 17 Mar 2025 19:17:13 -0700
john larkin <jlArbor.com> wrote:
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster <toaster@dne3.net> wrote:
Thank you for the advice. In my case I have a 10Mhz signal with very
sharp transitions (500ps, 5V) and wanted to make sure I did things
properly.
Interesting. What's generating the 5v signal? Lots of AC and Tiny
Logic chips are that fast, but might strain to drive 50 ohms. We use
several tiny triple buffers in parallel sometimes.
Regular thick-film surface-mount resistors are fine as terminators at
500 ps.
LVDS line receivers are great at the receive end.
I used a THS3111CD. Split up my project into a timing and driver board,
so i have some 50 ohm BNC cables between and wanted to be extra safe
about reflections at these higher frequencies.
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster <toaster@dne3.net> wrote:
Thank you for the advice. In my case I have a 10Mhz signal with very
sharp transitions (500ps, 5V) and wanted to make sure I did things >properly.
Interesting. What's generating the 5v signal? Lots of AC and Tiny
Logic chips are that fast, but might strain to drive 50 ohms. We use
several tiny triple buffers in parallel sometimes.
Regular thick-film surface-mount resistors are fine as terminators at
500 ps.
LVDS line receivers are great at the receive end.
Toaster <toaster@dne3.net> wrote:
On Mon, 17 Mar 2025 19:17:13 -0700
john larkin <jlArbor.com> wrote:
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster <toaster@dne3.net>
wrote:
Thank you for the advice. In my case I have a 10Mhz signal with
very sharp transitions (500ps, 5V) and wanted to make sure I did
things properly.
Interesting. What's generating the 5v signal? Lots of AC and Tiny
Logic chips are that fast, but might strain to drive 50 ohms. We
use several tiny triple buffers in parallel sometimes.
Regular thick-film surface-mount resistors are fine as terminators
at 500 ps.
LVDS line receivers are great at the receive end.
I used a THS3111CD. Split up my project into a timing and driver
board, so i have some 50 ohm BNC cables between and wanted to be
extra safe about reflections at these higher frequencies.
Hmm. 5V in 500 ps is pretty good going for a part with 1300 V/us
slew. ;)
Cheers
Phil Hobbs
On Mon, 17 Mar 2025 19:17:13 -0700
john larkin <jlArbor.com> wrote:
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster <toaster@dne3.net> wrote:
Thank you for the advice. In my case I have a 10Mhz signal with very
sharp transitions (500ps, 5V) and wanted to make sure I did things
properly.
Interesting. What's generating the 5v signal? Lots of AC and Tiny
Logic chips are that fast, but might strain to drive 50 ohms. We use
several tiny triple buffers in parallel sometimes.
Regular thick-film surface-mount resistors are fine as terminators at
500 ps.
LVDS line receivers are great at the receive end.
I used a THS3111CD. Split up my project into a timing and driver board,
so i have some 50 ohm BNC cables between and wanted to be extra safe
about reflections at these higher frequencies.
On Tue, 18 Mar 2025 18:29:42 -0400, Toaster <toaster@dne3.net> wrote:
On Mon, 17 Mar 2025 19:17:13 -0700
john larkin <jlArbor.com> wrote:
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster <toaster@dne3.net>
wrote:
Thank you for the advice. In my case I have a 10Mhz signal with
very sharp transitions (500ps, 5V) and wanted to make sure I did
things properly.
Interesting. What's generating the 5v signal? Lots of AC and Tiny
Logic chips are that fast, but might strain to drive 50 ohms. We
use several tiny triple buffers in parallel sometimes.
Regular thick-film surface-mount resistors are fine as terminators
at 500 ps.
LVDS line receivers are great at the receive end.
I used a THS3111CD. Split up my project into a timing and driver
board, so i have some 50 ohm BNC cables between and wanted to be
extra safe about reflections at these higher frequencies.
Is the signal some analog thing, or a 10 MHz clock? The THS is an
opamp, but they can make good cable drivers too, even for clocks.
Lately I'm enamored of BUF602, a unity-gain 1 GHz beast.
On Tue, 18 Mar 2025 16:02:45 -0700
john larkin <jl@glen--canyon.com> wrote:
On Tue, 18 Mar 2025 18:29:42 -0400, Toaster <toaster@dne3.net> wrote:
On Mon, 17 Mar 2025 19:17:13 -0700
john larkin <jlArbor.com> wrote:
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster <toaster@dne3.net>
wrote:
Thank you for the advice. In my case I have a 10Mhz signal with
very sharp transitions (500ps, 5V) and wanted to make sure I did
things properly.
Interesting. What's generating the 5v signal? Lots of AC and Tiny
Logic chips are that fast, but might strain to drive 50 ohms. We
use several tiny triple buffers in parallel sometimes.
Regular thick-film surface-mount resistors are fine as terminators
at 500 ps.
LVDS line receivers are great at the receive end.
I used a THS3111CD. Split up my project into a timing and driver
board, so i have some 50 ohm BNC cables between and wanted to be
extra safe about reflections at these higher frequencies.
Is the signal some analog thing, or a 10 MHz clock? The THS is an
opamp, but they can make good cable drivers too, even for clocks.
Lately I'm enamored of BUF602, a unity-gain 1 GHz beast.
I had a really hard time finding a good line driver. I might look into
this chip.
Thank you!
On Tue, 18 Mar 2025 18:59:44 -0400, Toaster <toaster@dne3.net> wrote:
On Tue, 18 Mar 2025 16:02:45 -0700
john larkin <jl@glen--canyon.com> wrote:
On Tue, 18 Mar 2025 18:29:42 -0400, Toaster <toaster@dne3.net>
wrote:
On Mon, 17 Mar 2025 19:17:13 -0700
john larkin <jlArbor.com> wrote:
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster <toaster@dne3.net>
wrote:
Thank you for the advice. In my case I have a 10Mhz signal with
very sharp transitions (500ps, 5V) and wanted to make sure I
did things properly.
Interesting. What's generating the 5v signal? Lots of AC and
Tiny Logic chips are that fast, but might strain to drive 50
ohms. We use several tiny triple buffers in parallel sometimes.
Regular thick-film surface-mount resistors are fine as
terminators at 500 ps.
LVDS line receivers are great at the receive end.
I used a THS3111CD. Split up my project into a timing and driver
board, so i have some 50 ohm BNC cables between and wanted to be
extra safe about reflections at these higher frequencies.
Is the signal some analog thing, or a 10 MHz clock? The THS is an
opamp, but they can make good cable drivers too, even for clocks.
Lately I'm enamored of BUF602, a unity-gain 1 GHz beast.
I had a really hard time finding a good line driver. I might look
into this chip.
Thank you!
Is your signal analog or digital?
On Tue, 18 Mar 2025 19:01:51 -0700
john larkin <jlArbor.com> wrote:
On Tue, 18 Mar 2025 18:59:44 -0400, Toaster <toaster@dne3.net> wrote:
On Tue, 18 Mar 2025 16:02:45 -0700
john larkin <jl@glen--canyon.com> wrote:
On Tue, 18 Mar 2025 18:29:42 -0400, Toaster <toaster@dne3.net>
wrote:
On Mon, 17 Mar 2025 19:17:13 -0700
john larkin <jlArbor.com> wrote:
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster <toaster@dne3.net>
wrote:
Thank you for the advice. In my case I have a 10Mhz signal with
very sharp transitions (500ps, 5V) and wanted to make sure I
did things properly.
Interesting. What's generating the 5v signal? Lots of AC and
Tiny Logic chips are that fast, but might strain to drive 50
ohms. We use several tiny triple buffers in parallel sometimes.
Regular thick-film surface-mount resistors are fine as
terminators at 500 ps.
LVDS line receivers are great at the receive end.
I used a THS3111CD. Split up my project into a timing and driver
board, so i have some 50 ohm BNC cables between and wanted to be
extra safe about reflections at these higher frequencies.
Is the signal some analog thing, or a 10 MHz clock? The THS is an
opamp, but they can make good cable drivers too, even for clocks.
Lately I'm enamored of BUF602, a unity-gain 1 GHz beast.
I had a really hard time finding a good line driver. I might look
into this chip.
Thank you!
Is your signal analog or digital?
digital
On Tue, 18 Mar 2025 19:01:51 -0700
john larkin <jlArbor.com> wrote:
On Tue, 18 Mar 2025 18:59:44 -0400, Toaster <toaster@dne3.net> wrote:
On Tue, 18 Mar 2025 16:02:45 -0700
john larkin <jl@glen--canyon.com> wrote:
On Tue, 18 Mar 2025 18:29:42 -0400, Toaster <toaster@dne3.net>
wrote:
On Mon, 17 Mar 2025 19:17:13 -0700
john larkin <jlArbor.com> wrote:
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster <toaster@dne3.net>
wrote:
Thank you for the advice. In my case I have a 10Mhz signal with
very sharp transitions (500ps, 5V) and wanted to make sure I
did things properly.
Interesting. What's generating the 5v signal? Lots of AC and
Tiny Logic chips are that fast, but might strain to drive 50
ohms. We use several tiny triple buffers in parallel sometimes.
Regular thick-film surface-mount resistors are fine as
terminators at 500 ps.
LVDS line receivers are great at the receive end.
I used a THS3111CD. Split up my project into a timing and driver
board, so i have some 50 ohm BNC cables between and wanted to be
extra safe about reflections at these higher frequencies.
Is the signal some analog thing, or a 10 MHz clock? The THS is an
opamp, but they can make good cable drivers too, even for clocks.
Lately I'm enamored of BUF602, a unity-gain 1 GHz beast.
I had a really hard time finding a good line driver. I might look
into this chip.
Thank you!
Is your signal analog or digital?
digital
On 19/03/2025 9:23 pm, Toaster wrote:
On Tue, 18 Mar 2025 19:01:51 -0700
john larkin <jlArbor.com> wrote:
On Tue, 18 Mar 2025 18:59:44 -0400, Toaster <toaster@dne3.net>
wrote:
On Tue, 18 Mar 2025 16:02:45 -0700
john larkin <jl@glen--canyon.com> wrote:
On Tue, 18 Mar 2025 18:29:42 -0400, Toaster <toaster@dne3.net>
wrote:
On Mon, 17 Mar 2025 19:17:13 -0700
john larkin <jlArbor.com> wrote:
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster <toaster@dne3.net>
wrote:
Thank you for the advice. In my case I have a 10Mhz signal
with very sharp transitions (500ps, 5V) and wanted to make
sure I did things properly.
Interesting. What's generating the 5v signal? Lots of AC and
Tiny Logic chips are that fast, but might strain to drive 50
ohms. We use several tiny triple buffers in parallel sometimes.
Regular thick-film surface-mount resistors are fine as
terminators at 500 ps.
LVDS line receivers are great at the receive end.
I used a THS3111CD. Split up my project into a timing and driver
board, so i have some 50 ohm BNC cables between and wanted to be
extra safe about reflections at these higher frequencies.
Is the signal some analog thing, or a 10 MHz clock? The THS is an
opamp, but they can make good cable drivers too, even for clocks.
Lately I'm enamored of BUF602, a unity-gain 1 GHz beast.
I had a really hard time finding a good line driver. I might look
into this chip.
Thank you!
Is your signal analog or digital?
digital
5V is a big swing for a modern digital system, but there are lots of
fast switching transistors out there that can cope with a 5V swing.
Discrete surface mount devices can be pretty compact, and there are
some fast integrated circuit devices designed to drive them.
Some of the ECL-to-TTL level shifters did generate a very fast full
0V to 5V swing. I got stuck with up-dating a very fast TTL-based
timing circuit in the early 1990's, and used a bit of ECLinPS ECL to
get rid of the usual TTL faults, and used 100k ECL-to-TTL converters
to push out the TTL house-keeping signals.
They were a lot better than the original TTL signals
It involved adding -4.5V rail to drive the ECL, but with surface
mount parts we could squeeze the additional stuff onto same sized
printed circuit board that the original system had used.
On Thu, 20 Mar 2025 01:41:29 +1100
Bill Sloman <bill.sloman@ieee.org> wrote:
On 19/03/2025 9:23 pm, Toaster wrote:
On Tue, 18 Mar 2025 19:01:51 -0700
john larkin <jlArbor.com> wrote:
On Tue, 18 Mar 2025 18:59:44 -0400, Toaster <toaster@dne3.net>
wrote:
On Tue, 18 Mar 2025 16:02:45 -0700
john larkin <jl@glen--canyon.com> wrote:
On Tue, 18 Mar 2025 18:29:42 -0400, Toaster <toaster@dne3.net>
wrote:
On Mon, 17 Mar 2025 19:17:13 -0700
john larkin <jlArbor.com> wrote:
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster <toaster@dne3.net> >>>>>>>> wrote:
Thank you for the advice. In my case I have a 10Mhz signal
with very sharp transitions (500ps, 5V) and wanted to make
sure I did things properly.
Interesting. What's generating the 5v signal? Lots of AC and
Tiny Logic chips are that fast, but might strain to drive 50
ohms. We use several tiny triple buffers in parallel sometimes. >>>>>>>>
Regular thick-film surface-mount resistors are fine as
terminators at 500 ps.
LVDS line receivers are great at the receive end.
I used a THS3111CD. Split up my project into a timing and driver >>>>>>> board, so i have some 50 ohm BNC cables between and wanted to be >>>>>>> extra safe about reflections at these higher frequencies.
Is the signal some analog thing, or a 10 MHz clock? The THS is an
opamp, but they can make good cable drivers too, even for clocks.
Lately I'm enamored of BUF602, a unity-gain 1 GHz beast.
I had a really hard time finding a good line driver. I might look
into this chip.
Thank you!
Is your signal analog or digital?
digital
5V is a big swing for a modern digital system, but there are lots of
fast switching transistors out there that can cope with a 5V swing.
Discrete surface mount devices can be pretty compact, and there are
some fast integrated circuit devices designed to drive them.
Some of the ECL-to-TTL level shifters did generate a very fast full
0V to 5V swing. I got stuck with up-dating a very fast TTL-based
timing circuit in the early 1990's, and used a bit of ECLinPS ECL to
get rid of the usual TTL faults, and used 100k ECL-to-TTL converters
to push out the TTL house-keeping signals.
They were a lot better than the original TTL signals
It involved adding -4.5V rail to drive the ECL, but with surface
mount parts we could squeeze the additional stuff onto same sized
printed circuit board that the original system had used.
fyi, im an amateur and may have made a mistake in my design, reason for
5V is so the logic chip in the other end gets around 2.5V after going
through the two 50 ohm resistors (voltage divider) and can trigger.
From what everyone is saying I dont even need to do that and can get a reliable termination just by using one 50 ohm resistor and avoid
dealing with the voltage divider side effect.
the hard part is coming up...soldering these tiny smd components...i
bought a microscope and a little platform to hold the boards. going to
try hot air soldering as i haven't shelled out for a reflow oven yet.
the logic chips im using in my project are 74VHC series.
On 20/03/2025 12:55 pm, Toaster wrote:
On Thu, 20 Mar 2025 01:41:29 +1100
Bill Sloman <bill.sloman@ieee.org> wrote:
On 19/03/2025 9:23 pm, Toaster wrote:
On Tue, 18 Mar 2025 19:01:51 -0700
john larkin <jlArbor.com> wrote:
On Tue, 18 Mar 2025 18:59:44 -0400, Toaster <toaster@dne3.net>
wrote:
On Tue, 18 Mar 2025 16:02:45 -0700
john larkin <jl@glen--canyon.com> wrote:
On Tue, 18 Mar 2025 18:29:42 -0400, Toaster <toaster@dne3.net>
wrote:
On Mon, 17 Mar 2025 19:17:13 -0700
john larkin <jlArbor.com> wrote:
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster
<toaster@dne3.net> wrote:
Thank you for the advice. In my case I have a 10Mhz signal >>>>>>>>> with very sharp transitions (500ps, 5V) and wanted to make >>>>>>>>> sure I did things properly.
Interesting. What's generating the 5v signal? Lots of AC and >>>>>>>> Tiny Logic chips are that fast, but might strain to drive 50 >>>>>>>> ohms. We use several tiny triple buffers in parallel
sometimes.
Regular thick-film surface-mount resistors are fine as
terminators at 500 ps.
LVDS line receivers are great at the receive end.
I used a THS3111CD. Split up my project into a timing and
driver board, so i have some 50 ohm BNC cables between and
wanted to be extra safe about reflections at these higher
frequencies.
Is the signal some analog thing, or a 10 MHz clock? The THS is
an opamp, but they can make good cable drivers too, even for
clocks.
Lately I'm enamored of BUF602, a unity-gain 1 GHz beast.
I had a really hard time finding a good line driver. I might
look into this chip.
Thank you!
Is your signal analog or digital?
digital
5V is a big swing for a modern digital system, but there are lots
of fast switching transistors out there that can cope with a 5V
swing.
Discrete surface mount devices can be pretty compact, and there are
some fast integrated circuit devices designed to drive them.
Some of the ECL-to-TTL level shifters did generate a very fast full
0V to 5V swing. I got stuck with up-dating a very fast TTL-based
timing circuit in the early 1990's, and used a bit of ECLinPS ECL
to get rid of the usual TTL faults, and used 100k ECL-to-TTL
converters to push out the TTL house-keeping signals.
They were a lot better than the original TTL signals
It involved adding -4.5V rail to drive the ECL, but with surface
mount parts we could squeeze the additional stuff onto same sized
printed circuit board that the original system had used.
fyi, im an amateur and may have made a mistake in my design, reason
for 5V is so the logic chip in the other end gets around 2.5V after
going through the two 50 ohm resistors (voltage divider) and can
trigger.
From what everyone is saying I dont even need to do that and can
get a reliable termination just by using one 50 ohm resistor and
avoid dealing with the voltage divider side effect.
the hard part is coming up...soldering these tiny smd components...i
bought a microscope and a little platform to hold the boards. going
to try hot air soldering as i haven't shelled out for a reflow oven
yet.
the logic chips im using in my project are 74VHC series.
I can sympathise with the difficulty of coming to terms with
soldering smd chips. Around 1989 I got stuck with introducing smd
parts to Cambridge Instruments in the UK, because the GaAs chips that
I needed to use only came in surface mount packages. We bought a
fairly expensive Groatmore hot-air reflow machine that would reflow individual packages.
When I wanted to use similar parts - Motorola ECLinPS devices - at
Nijmegen University in the Netherlands, nearly ten years later, they
just bought a much cheaper and smaller work station (but didn't let
me use it). At Haffmans BV in the Netherlands around 2002 I just used
a fine tipped soldering iron under a cheap binocular microscope.
It was fiddly work, but perfectly practical.
On Thu, 20 Mar 2025 16:28:38 +1100
Bill Sloman <bill.sloman@ieee.org> wrote:
On 20/03/2025 12:55 pm, Toaster wrote:
On Thu, 20 Mar 2025 01:41:29 +1100
Bill Sloman <bill.sloman@ieee.org> wrote:
On 19/03/2025 9:23 pm, Toaster wrote:
On Tue, 18 Mar 2025 19:01:51 -0700
john larkin <jlArbor.com> wrote:
On Tue, 18 Mar 2025 18:59:44 -0400, Toaster <toaster@dne3.net>
wrote:
On Tue, 18 Mar 2025 16:02:45 -0700
john larkin <jl@glen--canyon.com> wrote:
On Tue, 18 Mar 2025 18:29:42 -0400, Toaster <toaster@dne3.net> >>>>>>>> wrote:
On Mon, 17 Mar 2025 19:17:13 -0700
john larkin <jlArbor.com> wrote:
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster
<toaster@dne3.net> wrote:
That driver is so tiny I'm wondering if the 10Mhz switching speeds are
worth it! Researching some strange field interactions so I needed
something that could switch a decent voltage (300V) at repetition rates
close to 10Mhz. Odd requirements but until I can narrow down parameters
I need to sweep up the frequency range as far as I can.
On Tue, 18 Mar 2025 19:01:51 -0700
john larkin <jlArbor.com> wrote:
On Tue, 18 Mar 2025 18:59:44 -0400, Toaster <toaster@dne3.net> wrote:
On Tue, 18 Mar 2025 16:02:45 -0700
john larkin <jl@glen--canyon.com> wrote:
On Tue, 18 Mar 2025 18:29:42 -0400, Toaster <toaster@dne3.net>
wrote:
On Mon, 17 Mar 2025 19:17:13 -0700
john larkin <jlArbor.com> wrote:
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster <toaster@dne3.net>
wrote:
Thank you for the advice. In my case I have a 10Mhz signal with
very sharp transitions (500ps, 5V) and wanted to make sure I
did things properly.
Interesting. What's generating the 5v signal? Lots of AC and
Tiny Logic chips are that fast, but might strain to drive 50
ohms. We use several tiny triple buffers in parallel sometimes.
Regular thick-film surface-mount resistors are fine as
terminators at 500 ps.
LVDS line receivers are great at the receive end.
I used a THS3111CD. Split up my project into a timing and driver
board, so i have some 50 ohm BNC cables between and wanted to be
extra safe about reflections at these higher frequencies.
Is the signal some analog thing, or a 10 MHz clock? The THS is an
opamp, but they can make good cable drivers too, even for clocks.
Lately I'm enamored of BUF602, a unity-gain 1 GHz beast.
I had a really hard time finding a good line driver. I might look
into this chip.
Thank you!
Is your signal analog or digital?
digital
I use Tiny Logic triple buffers as line drivers, with all three
sections in parallel, and then sometimes two or three chips.
NL37WZ16US costs 10 cents.
That US8 package is nasty to solder or probe.
On 2025-03-19 10:41, john larkin wrote:> On Wed, 19 Mar 2025 06:23:25
-0400, Toaster <toaster@dne3.net> wrote:
On Tue, 18 Mar 2025 19:01:51 -0700
john larkin <jlArbor.com> wrote:
On Tue, 18 Mar 2025 18:59:44 -0400, Toaster <toaster@dne3.net> wrote:
On Tue, 18 Mar 2025 16:02:45 -0700
john larkin <jl@glen--canyon.com> wrote:
On Tue, 18 Mar 2025 18:29:42 -0400, Toaster <toaster@dne3.net>
wrote:
On Mon, 17 Mar 2025 19:17:13 -0700
john larkin <jlArbor.com> wrote:
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster <toaster@dne3.net> >>>>>>> wrote:
Thank you for the advice. In my case I have a 10Mhz signal with >>>>>>>> very sharp transitions (500ps, 5V) and wanted to make sure I >>>>>>>> did things properly.
Interesting. What's generating the 5v signal? Lots of AC and
Tiny Logic chips are that fast, but might strain to drive 50
ohms. We use several tiny triple buffers in parallel sometimes. >>>>>>>
Regular thick-film surface-mount resistors are fine as
terminators at 500 ps.
LVDS line receivers are great at the receive end.
I used a THS3111CD. Split up my project into a timing and driver >>>>>> board, so i have some 50 ohm BNC cables between and wanted to be >>>>>> extra safe about reflections at these higher frequencies.
Is the signal some analog thing, or a 10 MHz clock? The THS is an
opamp, but they can make good cable drivers too, even for clocks.
Lately I'm enamored of BUF602, a unity-gain 1 GHz beast.
I had a really hard time finding a good line driver. I might look
into this chip.
Thank you!
Is your signal analog or digital?
digital
I use Tiny Logic triple buffers as line drivers, with all three
sections in parallel, and then sometimes two or three chips.
NL37WZ16US costs 10 cents.
https://www.dropbox.com/scl/fi/gw7wetgtovqc04as2gxol/NL37WZ16_5V_Pulse.JPG?rlkey=2eqbyhds8l1myrzfjsrqwn5b3&raw=1
That US8 package is nasty to solder or probe.
Just rereading this. John, the prop delay spreads in the datasheet are
all over the place--almost a factor of 2 from typical to max over >temperature.
I'd expect the three sections to match OK, but paralleling packages
seems quite a lot sportier. How well does that work in production?
Cheers
Phil Hobbs
On 2025-03-19 10:41, john larkin wrote:> On Wed, 19 Mar 2025 06:23:25
-0400, Toaster <toaster@dne3.net> wrote:
On Tue, 18 Mar 2025 19:01:51 -0700
john larkin <jlArbor.com> wrote:
On Tue, 18 Mar 2025 18:59:44 -0400, Toaster <toaster@dne3.net> wrote:
On Tue, 18 Mar 2025 16:02:45 -0700
john larkin <jl@glen--canyon.com> wrote:
On Tue, 18 Mar 2025 18:29:42 -0400, Toaster <toaster@dne3.net>
wrote:
On Mon, 17 Mar 2025 19:17:13 -0700
john larkin <jlArbor.com> wrote:
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster <toaster@dne3.net>
wrote:
Thank you for the advice. In my case I have a 10Mhz signal with
very sharp transitions (500ps, 5V) and wanted to make sure I
did things properly.
Interesting. What's generating the 5v signal? Lots of AC and
Tiny Logic chips are that fast, but might strain to drive 50
ohms. We use several tiny triple buffers in parallel sometimes.
Regular thick-film surface-mount resistors are fine as
terminators at 500 ps.
LVDS line receivers are great at the receive end.
I used a THS3111CD. Split up my project into a timing and driver
board, so i have some 50 ohm BNC cables between and wanted to be
extra safe about reflections at these higher frequencies.
Is the signal some analog thing, or a 10 MHz clock? The THS is an
opamp, but they can make good cable drivers too, even for clocks.
Lately I'm enamored of BUF602, a unity-gain 1 GHz beast.
I had a really hard time finding a good line driver. I might look
into this chip.
Thank you!
Is your signal analog or digital?
digital
I use Tiny Logic triple buffers as line drivers, with all three
sections in parallel, and then sometimes two or three chips.
NL37WZ16US costs 10 cents.
https://www.dropbox.com/scl/fi/gw7wetgtovqc04as2gxol/NL37WZ16_5V_Pulse.JPG?rlkey=2eqbyhds8l1myrzfjsrqwn5b3&raw=1
That US8 package is nasty to solder or probe.
Just rereading this. John, the prop delay spreads in the datasheet are all over the place--almost a factor of 2 from typical to max over temperature.
I'd expect the three sections to match OK, but paralleling packages
seems quite a lot sportier. How well does that work in production?
Cheers
Phil Hobbs
Am 30.03.25 um 00:53 schrieb Phil Hobbs:
On 2025-03-19 10:41, john larkin wrote:> On Wed, 19 Mar 2025 06:23:25
-0400, Toaster <toaster@dne3.net> wrote:
https://www.dropbox.com/scl/fi/gw7wetgtovqc04as2gxol/NL37WZ16_5V_Pulse.JPG?rlkey=2eqbyhds8l1myrzfjsrqwn5b3&raw=1
On Tue, 18 Mar 2025 19:01:51 -0700
john larkin <jlArbor.com> wrote:
On Tue, 18 Mar 2025 18:59:44 -0400, Toaster <toaster@dne3.net> wrote: >> >>>
On Tue, 18 Mar 2025 16:02:45 -0700
john larkin <jl@glen--canyon.com> wrote:
On Tue, 18 Mar 2025 18:29:42 -0400, Toaster <toaster@dne3.net>
wrote:
On Mon, 17 Mar 2025 19:17:13 -0700
john larkin <jlArbor.com> wrote:
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster <toaster@dne3.net>
wrote:
Thank you for the advice. In my case I have a 10Mhz signal with
very sharp transitions (500ps, 5V) and wanted to make sure I
did things properly.
Interesting. What's generating the 5v signal? Lots of AC and
Tiny Logic chips are that fast, but might strain to drive 50
ohms. We use several tiny triple buffers in parallel sometimes.
Regular thick-film surface-mount resistors are fine as
terminators at 500 ps.
LVDS line receivers are great at the receive end.
I used a THS3111CD. Split up my project into a timing and driver
board, so i have some 50 ohm BNC cables between and wanted to be
extra safe about reflections at these higher frequencies.
Is the signal some analog thing, or a 10 MHz clock? The THS is an
opamp, but they can make good cable drivers too, even for clocks.
Lately I'm enamored of BUF602, a unity-gain 1 GHz beast.
I had a really hard time finding a good line driver. I might look
into this chip.
Thank you!
Is your signal analog or digital?
digital
I use Tiny Logic triple buffers as line drivers, with all three
sections in parallel, and then sometimes two or three chips.
NL37WZ16US costs 10 cents.
Just rereading this. John, the prop delay spreads in the datasheet are
That US8 package is nasty to solder or probe.
all over the place--almost a factor of 2 from typical to max over
temperature.
I'd expect the three sections to match OK, but paralleling packages
seems quite a lot sportier. How well does that work in production?
Cheers
Phil Hobbs
This here are 2 single TI 74LVC inverters, 100 Ohms on each output,
RG174 / RG188-like Coax into the 50 Ohm of an Agilent 2.4GHz scope.
< >https://www.flickr.com/photos/137684711@N07/32245910240/in/album-72157662535945536/
> + 2 pics to the right.
Sorry for the blue on black trace; it is default for input 3 that
happened to be unused. Looks better if downloaded.
Having a GND/VCC pair for each output is friendlier to GND bounce
and temp rise is also smaller in comparison to multichannel gates.
Gerhard
What scope is that? The gate may be a tad faster.
Splitting the 50r source terminator into 100's has virtues.
Am 30.03.25 um 00:53 schrieb Phil Hobbs:
On 2025-03-19 10:41, john larkin wrote:> On Wed, 19 Mar 2025 06:23:25
-0400, Toaster <toaster@dne3.net> wrote:
;wrote:
On Tue, 18 Mar 2025 19:01:51 -0700
john larkin <jlArbor.com> wrote:
;
On Tue, 18 Mar 2025 18:59:44 -0400, Toaster <toaster@dne3.net>
https://www.dropbox.com/scl/fi/gw7wetgtovqc04as2gxol/NL37WZ16_5V_Pulse.JPG?rlkey=2eqbyhds8l1myrzfjsrqwn5b3&raw=1;;;
On Tue, 18 Mar 2025 16:02:45 -0700;
john larkin <jl@glen--canyon.com> wrote:
;
On Tue, 18 Mar 2025 18:29:42 -0400, Toaster <toaster@dne3.net>;
wrote:
;
On Mon, 17 Mar 2025 19:17:13 -0700;
john larkin <jlArbor.com> wrote:
;
On Mon, 17 Mar 2025 19:50:17 -0400, Toaster <toaster@dne3.net>;
wrote:
;
Thank you for the advice. In my case I have a 10Mhz signal with >> Â >>>>>>>> very sharp transitions (500ps, 5V) and wanted to make sure I;
did things properly.
Interesting. What's generating the 5v signal? Lots of AC and
Tiny Logic chips are that fast, but might strain to drive 50
ohms. We use several tiny triple buffers in parallel sometimes.
;
Regular thick-film surface-mount resistors are fine as
terminators at 500 ps.
;
LVDS line receivers are great at the receive end.
;
;
I used a THS3111CD. Split up my project into a timing and driver
board, so i have some 50 ohm BNC cables between and wanted to be
extra safe about reflections at these higher frequencies.
Is the signal some analog thing, or a 10 MHz clock? The THS is an
opamp, but they can make good cable drivers too, even for clocks.
;
Lately I'm enamored of BUF602, a unity-gain 1 GHz beast.
;
I had a really hard time finding a good line driver. I might look
into this chip.
;
Thank you!
Is your signal analog or digital?
;
digital
I use Tiny Logic triple buffers as line drivers, with all three
sections in parallel, and then sometimes two or three chips.
;
NL37WZ16US costs 10 cents.
;
;
;Just rereading this. John, the prop delay spreads in the datasheet
That US8 package is nasty to solder or probe.
;
are all over the place--almost a factor of 2 from typical to max over
temperature.
I'd expect the three sections to match OK, but paralleling packages
seems quite a lot sportier. How well does that work in production?
Cheers
Phil Hobbs
This here are 2 single TI 74LVC inverters, 100 Ohms on each output,
RG174 / RG188-like Coax into the 50 Ohm of an Agilent 2.4GHz scope.
< https://www.flickr.com/photos/137684711@N07/32245910240/in/album-72157662535945536/
    >   + 2 pics to the right.
Sorry for the blue on black trace; it is default for input 3 that
happened to be unused. Looks better if downloaded.
Having a GND/VCC pair for each output is friendlier to GND bounce
and temp rise is also smaller in comparison to multichannel gates.
Gerhard
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