What is crosstalk noise

Unable to display preview. Download preview PDF. Skip to main content. This service is more advanced with JavaScript available. Advertisement Hide. Authors Authors and affiliations J. The following are illustrations of the two types of coupling and the simplest equivalent circuits in each case. In both cases, equations are indicated for the noise voltage Vn that occurs in nearby wiring pattern 2 due to noise in wiring pattern 1, which is a nearby noise source.

R is the resistance component, C is capacitance, M is mutual inductance, Vs is the noise source voltage, and Is is the noise source current. Here, it should be understood that crosstalk occurs across parallel wires.

It should also be noted that when the wires are perpendicular, the stray capacitance and mutual inductance are much smaller.

Noise Occurring in Switching Power Supplies. There is a coupling capacitance between A and V so aggressor node will try to fast pull up the victim node. This will affect the smooth transition of the victim node from low to high and will have a bump after half of the transition and this will result in a decrease in the transition time of the victim net. Figure-9 shows the transition of nets. Figure Crosstalk delay decrease.

Effects of crosstalk delay There are various effects of crosstalk delay on the timing of design. It could make unbalance a balanced clock tree, could violate the setup and hold timing. In this section, we will discuss some of them.

Crosstalk could unbalance a balanced clock tree. Crosstalk delay may increase or decrease the delay of clock buffers in the clock path and a balanced clock tree could be unbalanced as shown in the figure Let's suppose the latency of path P1 is L1 and for the path P2 is L2. If the clock tree is balanced then L1 must be equal to L2. Now due let's assume crosstalk delay occurs and it affects a clock buffer in clock path P2. Then now L1 will no more equal to L2 and now clock tree is not balanced.

Here we have considered only one clock buffer got affected by the crosstalk delay but in reality, the effect could be in many places. Crosstalk delay can violate the setup timing. Figure, shows the data path, launch clock path and capture clock path. For setup timing, data should reach the capture flop before the required time of capture flop.

So if there is an increase of delay in the data path or launch clock path it may cause setup violation. Setup violation may also happen if there is a decrease in delay on the capture clock path. These effects of crosstalk delay must be considered and fixed the timing. Hold timing may be violated due to crosstalk delay.

Figure, explains the situations where the hold time could violate due to crosstalk delay. If there is a decrease in the delay of any cells in the data path and launch clock or there is an increase of delay of cells in the capture clock path due to crosstalk delay, It may result in the hold timing violation. Such cases must be considered and fix the timing.