# How does TDR measure propagation delay?

## How does TDR measure propagation delay?

Calculate the MAX9979’s propagation delay. To make this measurement: Subtract the DATA1 PCB run of 0.695ns, and our delay is now 3.515ns. Subtract our DUT1 PCB run of 0.18ns, and our delay is now 3.335ns.

### What is TDR in transmission line?

A Time Domain Reflectometer (TDR) is a device used to detect the location of faults in transmission lines and coaxial cables. The TDR sends a low voltage pulsed signal through the transmission line and checks for any reflections seen due to impedance mismatch.

How do you calculate propagation delay on an oscilloscope?

You measure the delay in the test cable connecting the DUT1 output to the oscilloscope. You measure the total delay from the DATA1 and NDATA1 inputs to the DUT1 output and through the cable to the oscilloscope. The data from these measurements let you calculate the signal delay through the IC.

Why is propagation delay important?

Inconsistent propagation delay in an IC can cause data errors or race conditions on a chip. Therefore, the propagation delay is an important factor in high-speed circuit design and is a limiting factor of the processing speed, or hertz, that a processor can run at.

## What is propagation delay time?

In electronics, digital circuits and digital electronics, the propagation delay, or gate delay, is the length of time which starts when the input to a logic gate becomes stable and valid to change, to the time that the output of that logic gate is stable and valid to change.

### What does TDR measure?

The TDR technique measures the velocity of propagation of a high-frequency signal down waveguides in the soil. The velocity is related to the dielectric constant of the soil, which is then related to the water content.

What is TDR cable test?

A time-domain reflectometer (TDR) is an electronic instrument used to determine the characteristics of electrical lines by observing reflected waveforms. It can be used to characterize and locate faults in metallic cables (for example, twisted pair wire or coaxial cable).

What is TDR rate?

Transfer of Development Rights (TDR) means making available certain amount of additional built up area in preference of the area relinquished or surrendered by the owner of the land, so that he can use extra built up area either himself or transfer it to another in need of the extra built up area for an agreed sum of …

## What is full form of TDR?

TDR means Ticket Deposit Receipt. It is meant for people who do not undertake a train journey despite having a booked ticket and want to apply for a refund. IRCTC, the e-ticketing arm of Indian Railways, provides the facility for online filing of TDR.

### How does TDR show change in signal delay?

TDR is a method in which a high-speed signal edge is propagated down a signal path and the reflection is observed. The reflection will show both the impedances along that signal path, and the change in signal delay for each of those impedance changes. A simple tutorial for TDR is shown in Figure 1.

How is propagation delay and Delay Skew measured?

Google Propagation Delay and Delay Skew. The variation in twist rate over a long cable, creates a large difference in actual wiring length. This is measured on a good TDR as Propagation Delay, Delay Skew is how late the longer pair of data gets to it’s destination, and can be a factor as data volume and speed increase.

How to calculate the propagation delay of a max9979?

The delay from the MAX9979’s DUT1 (device under test) output through the SMA connector J18. The delay in the test cable that connects the DUT1 output to the CSA8000. The entire delay from the DATA1/NDATA1 inputs to the DUT1 output through the cable and to the CSA8000. Finally, the MAX9979’s true delay will be calculated.

## How does a time domain reflectometry ( TDR ) work?

A TDR works like radar. A fast rise time pulse is injected into the cable system at one end (near end). As the pulse travels down the cable, any change in the characteristic impedance (impedance discontinuities) will cause some of the incident signal to be reflected back towards the source.