Questions tagged [edge]

53 questions
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Is there an intuitive explanation of the classic edge-triggered flip flop circuit?

I figure there must be a way to understand it in terms of the three underlying latches somehow locking each other out, but I'm not getting it. Is there a way to understand the edge-triggered flip flop circuit other than trying all the combinations…
Ken Shirriff
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Why not nickel-plated edge connectors?

The tracks used as an edge connector are gold coated to improve contact with the female connector: bare Cu oxidizes, and also wears out if they are inserted and removed repeatedly. Au cannot be applied directly to Cu, so electroless Ni + immersion…
LW1ECP
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5
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How to generate edge-triggered pulse

First, a bit of background: I am just a hobbyist with electronics and have very little formal education in the area. I understand most terminology, but generally require a schematic for me to be able to create something of any decent complexity. I…
Vale H
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Minimizing signal delay when debouncing

I have a mechanical switch that I'd like to use as a signal source for a digital input of a microcontroller. The switch is normally closed, and I'd like to detect the switch being opened as quickly as I reasonably can, while also removing the…
Florian Ragwitz
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4
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5 answers

Convert falling / rising edge to pulses with minimal components

I have a signal that changes from high state to low every few minutes, after changing state it will remain constant, all level changes are clean. I'm looking for the smallest possible circuit that can detect a rising edge and falling edge (could be…
user34920
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Why do some PCBs have exposed copper along the edge even when mounted in plastic enclosure?

I've already read about reasons for exposing copper at the perimeter of a PCB (i.e. Why do some PCBs have exposed plated perimeters?). It seems that the main reason to completely expose the copper along the edge is to provide a seamless connection…
3
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3 answers

I2C data sampling is done at clock edge or level

I am trying to understand I2C data bus from this document. It explains the START-SLAVEADRESS-R/W-ACK-DATA.. as the master-slave take turns to get hold of the shared bus for mutual communication. One thing that I could not understand is related to…
alt-rose
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Long lines: whether or not to treat PCB traces as RF lines

My setup: 53 x 28 mm PCB, uC will run somewhere between 1 MHz and 8MHz. Dual layer PCB design. From the info I gathered on this site it seems there are two aspects to consider in deciding how to treat the PCB traces: 1) Maximum sinusoidal frequency…
kellogs
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How to clean up ringing / noise on rising edge of CMOS output?

I am feeding an interrupt input with the output from a CMOS Schmitt inverter. The falling edge of the inverter is nice and clean, But the rising edge is really dirty, and can get downright ugly at times. (See pictures) Why is the ringing so much…
jmd
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Why is D flip-flop positive edge triggered instead of level triggered?

I'm trying to understand this D type positive edge flip-flop: simulate this circuit – Schematic created using CircuitLab I'm having problem understanding why it is positive edge triggered and not level triggered. I understand that when the clock is…
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What is the purpose of the sharp edges (aka mouse bites, aka perforated breakaway tabs) on the PCB?

I have received an NVIDIA Jetson board this week and it has the following edges near the mount holes: I did a quick search on the internet but was only able to find similar edges on the Raspberry Pi Compute Module: Could you please explain me why…
berezovskyi
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Rising Edge vs Falling Edge D Flip-Flops

Is there any difference between a rising edge and a falling edge triggered D flip flop? For example, a falling edge flip flop will be faster or if there will be any change in result. Is it correct for me to add an inverter right before the clock…
jevan97
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Deciding which assembly is more common positive edge detector

I know of two circuits which can act as edge detector: A clock connected as a voltage source across a RC component where resistance is composed of a diode and a resistor and this in series with another A clock and its inverted output connected to…
Kutsit
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Overshoot on MOSFET drain

What can i do to minimize overshoot and undershoot when MOSFET switches on and off? (waveform taken using short ground spring probe, PCB is 2-layer) The rise and fall times should be less than 150ns. Here is the picture without snubber (R1, C27) I…
Andrius B.
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Why does this Edge Trigger Work on input of 555 monostable config?

I recently wired up a 555 timer in a mono stable configuration and found that when the trigger was held low for longer than the configured output pulse width, the output would stay high. After thinking about this.. it made sense. My 555 timer is…
Steven Lutz
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