27
votes
How do I make a nanoseconds counter?
You've changed the requirements by a lot! Measuring something in nanoseconds is hard. Measuring something with a +-100 ns accuracy really isn't. A 10 MHz counter works perfectly fine for that, do 20 ...
- 98.4k
16
votes
How do I make a nanoseconds counter?
Luxury option:
Time to digital converter chip, available from several manufacturers. Accuracy: picoseconds.
AS6500 TDC7200
Easy option:
Microcontroller timer in capture mode to measure pulse width, or ...
- 80.3k
15
votes
SN74LS93N is not counting as expected
I see two issues:
No decoupling caps. Edit: Add decoupling caps (see comment). When ICs switch state they draw a pulse of current on the 5V. Your power wires have enough inductance to cause the 5V to ...
- 16.6k
11
votes
Accepted
Why ripple counter increments on each 8th pulse
We can see from the datasheet, that the CD4020 has the following block diagram:
Notice the naming of the outputs, you have Q1, and ...
- 68.8k
10
votes
Design a 8 - 6 - 4 - 2 - 0 - 1 - 3 - 5 - 7 - 9... Counter
Given it is an assignment, I'm not going to work through the logic. However in all such questions you can boil it down to a circuit with two steps:
You have a binary ...
- 68.8k
9
votes
CPLD is (sometimes) not incrementing counter
Is the trigger input completely asynchronous to the 50MHz clock? If so, it probably violates the setup and hold time requirements from time to time. You need to ...
- 177k
9
votes
Resetting two CD4017 counters simultaneously, only one resets
You're using a "glitch" to reset your counters. In other words, when the reset pulse starts, it immediately removes the conditions for its own creation, so it's only as wide as the propagation delay ...
- 177k
9
votes
How do I make a nanoseconds counter?
(basically +/- 100ns).
Well then, a cheap 8-bit microncontroller like ATTINY2313 can be clocked at 20Mhz, then you can just use its timers in input capture mode and that will get you +/- 25ns ...
- 35.3k
8
votes
Discrete I2C counter IC
There is no shortage of small microcontrollers that have both:
Digital counter.
Built-in hardware I2C peripheral that can act as an I2C slave.
- 38.5k
8
votes
Accepted
Maximum frequency of the synchronous counter
The book is wrong. The minimum clock period is 30 ns.
First FF clock-to-Q: 10 ns
First AND gate in-to-out: 10 ns
Second AND gate in-to-out: 10 ns
Setup time to third FF: 0 ns
Total: 30 ns
This is ...
- 177k
8
votes
How do I make a nanoseconds counter?
I think the most realistic approach here is probably still a bit tricky:
First of all, you'll have to realize that your signal has a pretty high bandwidth, assuming that the rise time of your pulses ...
- 98.4k
7
votes
Design a Counter With an Arbitrary Sequence
If you write down the mapping of count states 0-7 to outputs
...
- 16.4k
7
votes
Accepted
Design a 8 - 6 - 4 - 2 - 0 - 1 - 3 - 5 - 7 - 9... Counter
It sounds like you are expected to solve this with a state-machine type circuit, however it can also be done using a classical counter circuit.
The key to this problem is recognizing that for half ...
- 46.9k
7
votes
Accepted
CPLD is (sometimes) not incrementing counter
Fist of all:Your trigger is coming in a-synchronous to the clock. You must first synchronize it before you can safely use it.
The code for that is:
...
- 14.5k
6
votes
Looking for a 74LS "friendly" decimal counter or BCD to decimal decoder (similar to CD4017)
This is a request for a recommendation, which is generally off-topic here, but I'll try to provide a generic answer for replacing CD4xxx chips with LS or HC compatible ones.
Replace CD40xxx with ...
6
votes
Up or Down Counter? FPGA
I've read that it is better to implement down counter because when implementing up counter you need one additional comparator and one additional adder so you would use less resources by making down ...
- 98.4k
6
votes
Accepted
Is it satisfactory for me to use the Clock speed to create a random 4-bit using a synchronous counter?
You can indeed use a free-running counter for this purpose.
The randomness is generated by the length of time the user pushes the button, so if the clock rate is significantly faster than the users ...
- 68.8k
6
votes
Accepted
Ripple counter from as few transistors as possible
Good question. I'll offer you a better question in return: you have to build that thing, right? So, is "least number of FETs" really the objective function here?
I'd argue it's not. When you ...
- 98.4k
5
votes
Discrete I2C counter IC
The PCF8593 is designed to optionally count events on a pin instead of time on a crystal.
From the NXP Semiconductor data sheet for the part:
- 363
5
votes
frequency counter
The LM386 is an audio amplifier and is completely unsuitable for RF. Your link is to a video so I'm not going to watch it, but I did see LM741 (ugh) so...
You need to convert your RF signal to a 0/...
5
votes
Finding frequency of a series of pulses (3 - 60 Hz) without using a microcontroller or frequency-to-voltage converter
Here's a hint: An edge-triggered retriggerable monostable multivibrator followed by a DFF makes a very effective frequency discriminator.1
simulate this circuit – Schematic created using ...
- 177k
5
votes
Accepted
Why is my 8-bit counter only counting until 127?
In the Modelsim waveform display, you need to right-click on the output signal and change the data representation to unsigned. It's currently interpreting the 8-bit value as a signed integer.
- 177k
5
votes
Accepted
Designing a electronic dice with Arduino, 74HC163 and a 74HC4511 decoder to a 7segment display
Overview
Essentially, you want a 1-6 counter -- either up or down. So let's go with up.
Excitation Table
Excitation tables often used to work out the combinatorial logic needed to transition a set of ...
- 78.5k
5
votes
How do I make a nanoseconds counter?
Counting pulses with 1ns precision is a tall order. That rate rules out all the commonly used logic families like 74XX, CD4XXX, etc. Even the "high speed" varieties are nowhere near fast ...
- 7,967
5
votes
Will the LVDS signal rise time improve after a counter IC?
Yes, you should expect to see a 100 ps rise fall time at the output. The path from the clock to the counter output has a large gain and a circuit which clips the amplitude thus decreasing the rise/...
- 412
4
votes
How to count the number of high voltages in Hantek Oscilloscope?
With the additional data you've now posted, the answer is simple:
You cannot.
The bandwidth of your scope is not up to the task of viewing a USB2.0 signal.
USB2.0 runs at 200MHz, and your scope has ...
- 73.1k
4
votes
Discrete I2C counter IC
If you have to have an off board solution with timing. Use a CPLD, then you can get what ever logic you want. The design complexity goes up, but you will save power. Price starts at ~1.5 with quantity....
- 87.2k
4
votes
Accepted
Counting signal frequency with binary counter
Am only going to address your question about reading the count output from a '393 counter. You have two problems to overcome.
This counter is asynchronous, which means that a clock input ripples ...
- 27.1k
4
votes
Are 7490N & 74LS190N Same IC's?
Nope... different families, different function, different pin count, different chips. They are both counters, but different kinds and that's about it.
7490 74LS190
- 46.9k
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