If you google use d-flop as one-shot
you get some remarkably silly circuits. Many just swipe from this
image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
"john larkin" <jlarkin_highland_tech> wrote in message news:ject8j1199btt6q6k5a7o57q01hqsvcj20@4ax.com...
If you google use d-flop as one-shot
you get some remarkably silly circuits. Many just swipe from this
image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
One way to shorten a pulse derived from a clock signal is to clear the d-type with the clock signal.
Suppose you have a 1 clock cycle pulse produced by a d-type.
Connect it to d on another d-type, connect the clock as usual but also connect the clock to /clear
A 74HC74 d-type will clock and Q will go high but then it will be cleared by the clock going low and so Q will go low half a clock
later.
You can debate whether or not this violates any setup/hold or other timing requirements and you can always delay the /reset signal
with a gate or two if needed.
I've seen this work fine in an experimental design using 74HC74 with clk and /reset connected together.
If you google use d-flop as one-shot
you get some remarkably silly circuits. Many just swipe from this
image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
On 7/10/2024 12:16 PM, john larkin wrote:
If you google use d-flop as one-shot
you get some remarkably silly circuits. Many just swipe from this
image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
I get better hits using the term "monostable":
<https://www.n5dux.com/ham/files/pdf/Working%20With%20Monostable%20Multivibrators.pdf>
Fig 9 is about as simple as it gets. I don't understand why the extra
flop and the low pass and stuff after the button in the link you posted,
it's like they never heard of a passive differentiator before.
On Wed, 10 Jul 2024 16:25:51 -0400, "Edward Rawde"
<invalid@invalid.invalid> wrote:
"john larkin" <jlarkin_highland_tech> wrote in message news:ject8j1199btt6q6k5a7o57q01hqsvcj20@4ax.com...
If you google use d-flop as one-shot
you get some remarkably silly circuits. Many just swipe from this
image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
One way to shorten a pulse derived from a clock signal is to clear the d-type with the clock signal.
Suppose you have a 1 clock cycle pulse produced by a d-type.
Connect it to d on another d-type, connect the clock as usual but also connect the clock to /clear
A 74HC74 d-type will clock and Q will go high but then it will be cleared by the clock going low and so Q will go low half a clock
later.
You can debate whether or not this violates any setup/hold or other timing requirements and you can always delay the /reset signal
with a gate or two if needed.
I've seen this work fine in an experimental design using 74HC74 with clk and /reset connected together.
That assumes that the going-away prop delay of the reset path is
faster than the clock path. Might be for some flops.
On Wed, 10 Jul 2024 15:56:51 -0400, bitrex <user@example.net> wrote:
On 7/10/2024 12:16 PM, john larkin wrote:Yikes, 36 years old. CD4000B logic.
If you google use d-flop as one-shotI get better hits using the term "monostable":
you get some remarkably silly circuits. Many just swipe from this
image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
<https://www.n5dux.com/ham/files/pdf/ Working%20With%20Monostable%20Multivibrators.pdf>
Fig 9 is about as simple as it gets. I don't understand why the extra
flop and the low pass and stuff after the button in the link you posted, >>it's like they never heard of a passive differentiator before.
I like d-flop one-shots because they are fast, truly edge-triggered, and
can be gated with the D input.
But RC feedback into a reset input is risky at best. Some flops simply
won't work that way... they hang up.
On Wed, 10 Jul 2024 14:07:55 -0700, john larkin wrote:
On Wed, 10 Jul 2024 15:56:51 -0400, bitrex <user@example.net> wrote:
On 7/10/2024 12:16 PM, john larkin wrote:Yikes, 36 years old. CD4000B logic.
If you google use d-flop as one-shotI get better hits using the term "monostable":
you get some remarkably silly circuits. Many just swipe from this
image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
<https://www.n5dux.com/ham/files/pdf/ >Working%20With%20Monostable%20Multivibrators.pdf>
Fig 9 is about as simple as it gets. I don't understand why the extra >>>flop and the low pass and stuff after the button in the link you posted, >>>it's like they never heard of a passive differentiator before.
I like d-flop one-shots because they are fast, truly edge-triggered, and
can be gated with the D input.
But RC feedback into a reset input is risky at best. Some flops simply
won't work that way... they hang up.
Is this in furtherence of your TDR experimentation? I can't think of
anything else a one-shot is useful for.
If you google use d-flop as one-shot
you get some remarkably silly circuits. Many just swipe from this
image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
On Wed, 10 Jul 2024 22:50:54 -0000 (UTC), Cursitor Doom <cd999666@notformail.com> wrote:
On Wed, 10 Jul 2024 14:07:55 -0700, john larkin wrote:
On Wed, 10 Jul 2024 15:56:51 -0400, bitrex <user@example.net> wrote:Working%20With%20Monostable%20Multivibrators.pdf>
On 7/10/2024 12:16 PM, john larkin wrote:
If you google use d-flop as one-shotI get better hits using the term "monostable":
you get some remarkably silly circuits. Many just swipe from this
image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
<https://www.n5dux.com/ham/files/pdf/
Yikes, 36 years old. CD4000B logic.
Fig 9 is about as simple as it gets. I don't understand why the extra
flop and the low pass and stuff after the button in the link you posted, >>>> it's like they never heard of a passive differentiator before.
I like d-flop one-shots because they are fast, truly edge-triggered, and >>> can be gated with the D input.
But RC feedback into a reset input is risky at best. Some flops simply
won't work that way... they hang up.
Is this in furtherence of your TDR experimentation? I can't think of
anything else a one-shot is useful for.
Phil is doing a TDR project. I'm mostly doing slow precision stuff
lately.
I am planning a few new products, and one is a sort of precision pulse generator. I was thinking to have the "HIT" flop, the first trigger recognizer, be the one-shot. But it's easier to put that inside an
FPGA. The problem with FPGAs is time jitter, from all the routing
crosstalk and clock feedthru and ground bounce and power supply
sensitivity. Maybe they can be managed.
I tested one Xilinx chip for pin-to-pin delay sensitivity vs core
supply voltage. It measured 70 microvolts per picosecond.
Some people think one-shots are evil, but I like them.
If you google use d-flop as one-shot
you get some remarkably silly circuits. Many just swipe from this
image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
On a sunny day (Wed, 10 Jul 2024 09:16:36 -0700) it happened john larkin ><jlarkin_highland_tech> wrote in <ject8j1199btt6q6k5a7o57q01hqsvcj20@4ax.com>:
If you google use d-flop as one-shot
you get some remarkably silly circuits. Many just swipe from this
image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
Old as the world,
74121 is simpler?
On Wed, 10 Jul 2024 09:16:36 -0700, john larkin
<jlarkin_highland_tech> wrote:
If you google use d-flop as one-shot
you get some remarkably silly circuits. Many just swipe from this
image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
So don't google that.
On Thu, 11 Jul 2024 05:32:42 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
On a sunny day (Wed, 10 Jul 2024 09:16:36 -0700) it happened john larkin >><jlarkin_highland_tech> wrote in <ject8j1199btt6q6k5a7o57q01hqsvcj20@4ax.com>:
If you google use d-flop as one-shot
you get some remarkably silly circuits. Many just swipe from this
image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
Old as the world,
74121 is simpler?
SN74LVC1G123DCU is a nice little part. Good for flashing LEDs and
such.
On Wed, 10 Jul 2024 22:50:54 -0000 (UTC), Cursitor Doom <cd999666@notformail.com> wrote:
On Wed, 10 Jul 2024 14:07:55 -0700, john larkin wrote:
On Wed, 10 Jul 2024 15:56:51 -0400, bitrex <user@example.net> wrote:Working%20With%20Monostable%20Multivibrators.pdf>
On 7/10/2024 12:16 PM, john larkin wrote:
If you google use d-flop as one-shotI get better hits using the term "monostable":
you get some remarkably silly circuits. Many just swipe from this
image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
<https://www.n5dux.com/ham/files/pdf/
Yikes, 36 years old. CD4000B logic.
Fig 9 is about as simple as it gets. I don't understand why the extra
flop and the low pass and stuff after the button in the link you posted, >>>> it's like they never heard of a passive differentiator before.
I like d-flop one-shots because they are fast, truly edge-triggered, and >>> can be gated with the D input.
But RC feedback into a reset input is risky at best. Some flops simply
won't work that way... they hang up.
Is this in furtherence of your TDR experimentation? I can't think of
anything else a one-shot is useful for.
Phil is doing a TDR project. I'm mostly doing slow precision stuff
lately.
I am planning a few new products, and one is a sort of precision pulse generator. I was thinking to have the "HIT" flop, the first trigger recognizer, be the one-shot. But it's easier to put that inside an
FPGA. The problem with FPGAs is time jitter, from all the routing
crosstalk and clock feedthru and ground bounce and power supply
sensitivity. Maybe they can be managed.
I tested one Xilinx chip for pin-to-pin delay sensitivity vs core
supply voltage. It measured 70 microvolts per picosecond.
Some people think one-shots are evil, but I like them.
On 7/10/2024 8:16 PM, john larkin wrote:
On Wed, 10 Jul 2024 22:50:54 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
On Wed, 10 Jul 2024 14:07:55 -0700, john larkin wrote:
On Wed, 10 Jul 2024 15:56:51 -0400, bitrex <user@example.net> wrote:Working%20With%20Monostable%20Multivibrators.pdf>
On 7/10/2024 12:16 PM, john larkin wrote:
If you google  use d-flop as one-shotI get better hits using the term "monostable":
you get some remarkably silly circuits. Many just swipe from this
image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
<https://www.n5dux.com/ham/files/pdf/
Yikes, 36 years old. CD4000B logic.
Fig 9 is about as simple as it gets. I don't understand why the extra >>>>> flop and the low pass and stuff after the button in the link you
posted,
it's like they never heard of a passive differentiator before.
I like d-flop one-shots because they are fast, truly edge-triggered,
and
can be gated with the D input.
But RC feedback into a reset input is risky at best. Some flops simply >>>> won't work that way... they hang up.
Is this in furtherence of your TDR experimentation? I can't think of
anything else a one-shot is useful for.
Phil is doing a TDR project. I'm mostly doing slow precision stuff
lately.
I am planning a few new products, and one is a sort of precision pulse
generator. I was thinking to have the "HIT" flop, the first trigger
recognizer, be the one-shot. But it's easier to put that inside an
FPGA. The problem with FPGAs is time jitter, from all the routing
crosstalk and clock feedthru and ground bounce and power supply
sensitivity. Maybe they can be managed.
I tested one Xilinx chip for pin-to-pin delay sensitivity vs core
supply voltage. It measured 70 microvolts per picosecond.
Some people think one-shots are evil, but I like them.
The supply to delay variation in the Greenpak SPLD 16 bit counter
configured as a one-shot is around 10, in simulation anyway..
On 7/11/2024 12:01 PM, bitrex wrote:
On 7/10/2024 8:16 PM, john larkin wrote:
On Wed, 10 Jul 2024 22:50:54 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
On Wed, 10 Jul 2024 14:07:55 -0700, john larkin wrote:
On Wed, 10 Jul 2024 15:56:51 -0400, bitrex <user@example.net> wrote: >>>>>Working%20With%20Monostable%20Multivibrators.pdf>
On 7/10/2024 12:16 PM, john larkin wrote:
If you google use d-flop as one-shotI get better hits using the term "monostable":
you get some remarkably silly circuits. Many just swipe from this >>>>>>> image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
<https://www.n5dux.com/ham/files/pdf/
Yikes, 36 years old. CD4000B logic.
Fig 9 is about as simple as it gets. I don't understand why the extra >>>>>> flop and the low pass and stuff after the button in the link you
posted,
it's like they never heard of a passive differentiator before.
I like d-flop one-shots because they are fast, truly edge-triggered, >>>>> and
can be gated with the D input.
But RC feedback into a reset input is risky at best. Some flops simply >>>>> won't work that way... they hang up.
Is this in furtherence of your TDR experimentation? I can't think of
anything else a one-shot is useful for.
Phil is doing a TDR project. I'm mostly doing slow precision stuff
lately.
I am planning a few new products, and one is a sort of precision pulse
generator. I was thinking to have the "HIT" flop, the first trigger
recognizer, be the one-shot. But it's easier to put that inside an
FPGA. The problem with FPGAs is time jitter, from all the routing
crosstalk and clock feedthru and ground bounce and power supply
sensitivity. Maybe they can be managed.
I tested one Xilinx chip for pin-to-pin delay sensitivity vs core
supply voltage. It measured 70 microvolts per picosecond.
Some people think one-shots are evil, but I like them.
The supply to delay variation in the Greenpak SPLD 16 bit counter
configured as a one-shot is around 10, in simulation anyway..
I'll try to measure it this weekend, I'm interested to see. What general >length of one-shot are we talking?
On Thu, 11 Jul 2024 12:23:25 -0400, bitrex <user@example.net> wrote:
On 7/11/2024 12:01 PM, bitrex wrote:
On 7/10/2024 8:16 PM, john larkin wrote:
On Wed, 10 Jul 2024 22:50:54 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
On Wed, 10 Jul 2024 14:07:55 -0700, john larkin wrote:
On Wed, 10 Jul 2024 15:56:51 -0400, bitrex <user@example.net> wrote: >>>>>>Working%20With%20Monostable%20Multivibrators.pdf>
On 7/10/2024 12:16 PM, john larkin wrote:
If you google  use d-flop as one-shotI get better hits using the term "monostable":
you get some remarkably silly circuits. Many just swipe from this >>>>>>>> image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
<https://www.n5dux.com/ham/files/pdf/
Yikes, 36 years old. CD4000B logic.
Fig 9 is about as simple as it gets. I don't understand why the extra >>>>>>> flop and the low pass and stuff after the button in the link you >>>>>>> posted,
it's like they never heard of a passive differentiator before.
I like d-flop one-shots because they are fast, truly edge-triggered, >>>>>> and
can be gated with the D input.
But RC feedback into a reset input is risky at best. Some flops simply >>>>>> won't work that way... they hang up.
Is this in furtherence of your TDR experimentation? I can't think of >>>>> anything else a one-shot is useful for.
Phil is doing a TDR project. I'm mostly doing slow precision stuff
lately.
I am planning a few new products, and one is a sort of precision pulse >>>> generator. I was thinking to have the "HIT" flop, the first trigger
recognizer, be the one-shot. But it's easier to put that inside an
FPGA. The problem with FPGAs is time jitter, from all the routing
crosstalk and clock feedthru and ground bounce and power supply
sensitivity. Maybe they can be managed.
I tested one Xilinx chip for pin-to-pin delay sensitivity vs core
supply voltage. It measured 70 microvolts per picosecond.
Some people think one-shots are evil, but I like them.
The supply to delay variation in the Greenpak SPLD 16 bit counter
configured as a one-shot is around 10, in simulation anyway..
I'll try to measure it this weekend, I'm interested to see. What general
length of one-shot are we talking?
In one application, just a few nanoseconds. I figured that I could run
\Q to \Reset through a gate or two.
I would use the D input of the flop for "pulse picking".
On 7/11/2024 5:21 PM, john larkin wrote:
On Thu, 11 Jul 2024 12:23:25 -0400, bitrex <user@example.net> wrote:
On 7/11/2024 12:01 PM, bitrex wrote:
On 7/10/2024 8:16 PM, john larkin wrote:
On Wed, 10 Jul 2024 22:50:54 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
On Wed, 10 Jul 2024 14:07:55 -0700, john larkin wrote:
On Wed, 10 Jul 2024 15:56:51 -0400, bitrex <user@example.net> wrote: >>>>>>>Working%20With%20Monostable%20Multivibrators.pdf>
On 7/10/2024 12:16 PM, john larkin wrote:
If you google use d-flop as one-shotI get better hits using the term "monostable":
you get some remarkably silly circuits. Many just swipe from this >>>>>>>>> image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
<https://www.n5dux.com/ham/files/pdf/
Yikes, 36 years old. CD4000B logic.
Fig 9 is about as simple as it gets. I don't understand why the extra >>>>>>>> flop and the low pass and stuff after the button in the link you >>>>>>>> posted,
it's like they never heard of a passive differentiator before. >>>>>>>>
I like d-flop one-shots because they are fast, truly edge-triggered, >>>>>>> and
can be gated with the D input.
But RC feedback into a reset input is risky at best. Some flops simply >>>>>>> won't work that way... they hang up.
Is this in furtherence of your TDR experimentation? I can't think of >>>>>> anything else a one-shot is useful for.
Phil is doing a TDR project. I'm mostly doing slow precision stuff
lately.
I am planning a few new products, and one is a sort of precision pulse >>>>> generator. I was thinking to have the "HIT" flop, the first trigger
recognizer, be the one-shot. But it's easier to put that inside an
FPGA. The problem with FPGAs is time jitter, from all the routing
crosstalk and clock feedthru and ground bounce and power supply
sensitivity. Maybe they can be managed.
I tested one Xilinx chip for pin-to-pin delay sensitivity vs core
supply voltage. It measured 70 microvolts per picosecond.
Some people think one-shots are evil, but I like them.
The supply to delay variation in the Greenpak SPLD 16 bit counter
configured as a one-shot is around 10, in simulation anyway..
I'll try to measure it this weekend, I'm interested to see. What general >>> length of one-shot are we talking?
In one application, just a few nanoseconds. I figured that I could run
\Q to \Reset through a gate or two.
I would use the D input of the flop for "pulse picking".
Yeah that's tough cuz even at 50 MHz 1 clock is 20 ns and at low counts >there's also a variable offset a la:
pulse length = [(Counter data + 1) / CLK input frequency – Offset],
Where Offset could be in the range 10s of ns at that clock frequency,
worst case, independent of supply
On Fri, 12 Jul 2024 12:27:21 -0400, bitrex <user@example.net> wrote:
On 7/11/2024 5:21 PM, john larkin wrote:
On Thu, 11 Jul 2024 12:23:25 -0400, bitrex <user@example.net> wrote:
On 7/11/2024 12:01 PM, bitrex wrote:
On 7/10/2024 8:16 PM, john larkin wrote:
On Wed, 10 Jul 2024 22:50:54 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
On Wed, 10 Jul 2024 14:07:55 -0700, john larkin wrote:
On Wed, 10 Jul 2024 15:56:51 -0400, bitrex <user@example.net> wrote: >>>>>>>>Working%20With%20Monostable%20Multivibrators.pdf>
On 7/10/2024 12:16 PM, john larkin wrote:
If you google  use d-flop as one-shotI get better hits using the term "monostable":
you get some remarkably silly circuits. Many just swipe from this >>>>>>>>>> image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm
<https://www.n5dux.com/ham/files/pdf/
Yikes, 36 years old. CD4000B logic.
Fig 9 is about as simple as it gets. I don't understand why the extra >>>>>>>>> flop and the low pass and stuff after the button in the link you >>>>>>>>> posted,
it's like they never heard of a passive differentiator before. >>>>>>>>>
I like d-flop one-shots because they are fast, truly edge-triggered, >>>>>>>> and
can be gated with the D input.
But RC feedback into a reset input is risky at best. Some flops simply >>>>>>>> won't work that way... they hang up.
Is this in furtherence of your TDR experimentation? I can't think of >>>>>>> anything else a one-shot is useful for.
Phil is doing a TDR project. I'm mostly doing slow precision stuff >>>>>> lately.
I am planning a few new products, and one is a sort of precision pulse >>>>>> generator. I was thinking to have the "HIT" flop, the first trigger >>>>>> recognizer, be the one-shot. But it's easier to put that inside an >>>>>> FPGA. The problem with FPGAs is time jitter, from all the routing
crosstalk and clock feedthru and ground bounce and power supply
sensitivity. Maybe they can be managed.
I tested one Xilinx chip for pin-to-pin delay sensitivity vs core
supply voltage. It measured 70 microvolts per picosecond.
Some people think one-shots are evil, but I like them.
The supply to delay variation in the Greenpak SPLD 16 bit counter
configured as a one-shot is around 10, in simulation anyway..
I'll try to measure it this weekend, I'm interested to see. What general >>>> length of one-shot are we talking?
In one application, just a few nanoseconds. I figured that I could run
\Q to \Reset through a gate or two.
I would use the D input of the flop for "pulse picking".
Yeah that's tough cuz even at 50 MHz 1 clock is 20 ns and at low counts
there's also a variable offset a la:
pulse length = [(Counter data + 1) / CLK input frequency – Offset],
Where Offset could be in the range 10s of ns at that clock frequency,
worst case, independent of supply
A 1 ns Tiny flop and a 1 ns gate (or even a PCB delay line) would make
a gated one-shot that would run at a couple hundred MHz.
Connecting \Q directly to \R would be interesting. I should try that.
The 1 ns cmos flop is NC7SV74.
On 7/12/2024 12:36 PM, john larkin wrote:
On Fri, 12 Jul 2024 12:27:21 -0400, bitrex <user@example.net> wrote:
On 7/11/2024 5:21 PM, john larkin wrote:
On Thu, 11 Jul 2024 12:23:25 -0400, bitrex <user@example.net> wrote:
On 7/11/2024 12:01 PM, bitrex wrote:
On 7/10/2024 8:16 PM, john larkin wrote:
On Wed, 10 Jul 2024 22:50:54 -0000 (UTC), Cursitor Doom
<cd999666@notformail.com> wrote:
On Wed, 10 Jul 2024 14:07:55 -0700, john larkin wrote:
On Wed, 10 Jul 2024 15:56:51 -0400, bitrex <user@example.net> wrote: >>>>>>>>>Working%20With%20Monostable%20Multivibrators.pdf>
On 7/10/2024 12:16 PM, john larkin wrote:
If you google use d-flop as one-shotI get better hits using the term "monostable":
you get some remarkably silly circuits. Many just swipe from this >>>>>>>>>>> image:
http://www.discovercircuits.com/DJ-Circuits/oneshots.htm >>>>>>>>>>>
<https://www.n5dux.com/ham/files/pdf/
Yikes, 36 years old. CD4000B logic.
Fig 9 is about as simple as it gets. I don't understand why the extra
flop and the low pass and stuff after the button in the link you >>>>>>>>>> posted,
it's like they never heard of a passive differentiator before. >>>>>>>>>>
I like d-flop one-shots because they are fast, truly edge-triggered, >>>>>>>>> and
can be gated with the D input.
But RC feedback into a reset input is risky at best. Some flops simply
won't work that way... they hang up.
Is this in furtherence of your TDR experimentation? I can't think of >>>>>>>> anything else a one-shot is useful for.
Phil is doing a TDR project. I'm mostly doing slow precision stuff >>>>>>> lately.
I am planning a few new products, and one is a sort of precision pulse >>>>>>> generator. I was thinking to have the "HIT" flop, the first trigger >>>>>>> recognizer, be the one-shot. But it's easier to put that inside an >>>>>>> FPGA. The problem with FPGAs is time jitter, from all the routing >>>>>>> crosstalk and clock feedthru and ground bounce and power supply
sensitivity. Maybe they can be managed.
I tested one Xilinx chip for pin-to-pin delay sensitivity vs core >>>>>>> supply voltage. It measured 70 microvolts per picosecond.
Some people think one-shots are evil, but I like them.
The supply to delay variation in the Greenpak SPLD 16 bit counter
configured as a one-shot is around 10, in simulation anyway..
I'll try to measure it this weekend, I'm interested to see. What general >>>>> length of one-shot are we talking?
In one application, just a few nanoseconds. I figured that I could run >>>> \Q to \Reset through a gate or two.
I would use the D input of the flop for "pulse picking".
Yeah that's tough cuz even at 50 MHz 1 clock is 20 ns and at low counts
there's also a variable offset a la:
pulse length = [(Counter data + 1) / CLK input frequency – Offset],
Where Offset could be in the range 10s of ns at that clock frequency,
worst case, independent of supply
A 1 ns Tiny flop and a 1 ns gate (or even a PCB delay line) would make
a gated one-shot that would run at a couple hundred MHz.
Connecting \Q directly to \R would be interesting. I should try that.
The 1 ns cmos flop is NC7SV74.
What about using a PCB delay line, and diff amp and driver to take the >difference between a short and long path
Yikes, 36 years old. CD4000B logic.
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