Test Yourself | Signal Integrity Solutions

#1 The bandwidth of a digital signal at 10 Gbps is:

Fifth Harmony – 50 GHz

Fifth Harmony – 25 GHz

Depends on rise time

Depends on signal encoding

#2 What do these three terminations have in common: R-C, Thevenin, VTT?

Savings in the static power dissipation of the termination

Saving in the BOM

They allow the high output resistance of the transmitter to be overcome

PCB real-estate saving arrangement

#3 In the resonance frequency created by the stub, what happens to most of the energy transmitted from the transmitter?

It is lost as radiation

It is lost in dielectric losses

It is lost in conductivity losses

It returns to the transmitter

#4 In an asymmetric stripline structure, by how much should conductors be separated in order to reduce cross-talk substantially?

3·W

3·H1

3·H2

3·max (H1, H2, W)

#5 How can FEXT be reduced in a stripline?

Reduce coupling length between the aggressor line and the victim

Extend the aggressor’s rise/fall time

Answers A and B are correct

There is no need to do anything because FEXT=0

#6 Coupling length between aggressor line and victim line is 6 inches. The aggressor’s voltage rise time is 1 nS. What will happen to the NEXT’s intensity if rise time decreases to 0.1 nS?

It will multiply by 10

It will be reduced 10 times

It will not change

It will increase by an unknown amount

#7 What mainly affects the intensity of the differential NEXT between differential lines?

Depends on the aggressor’s differential pair coupling: tightly or loosely coupled

Depends on the victim’s differential pair coupling: tightly or loosely coupled

The NEXT is relatively the same in the P and N lines, therefore the differential NEXT is equal to about 0

Affected mainly by the nearest aggressor and victim lines

#8 What is Common Mode?

The common (average) voltage between lines P and N

The conductors' mode for common excitation

A combination of the concepts in answers A and B

Conductor impedance for common excitation

#9 The Nyquist frequency of a 56 Gbps signal encoded in PAM 4 is

112 GHz

56 GHz

28 GHz

14 GHz

#10 A transmitter output connected to a 50-ohm transmission line varies from 0 to 3.3V. Assuming the transmitter current was 0 before the change, when does the current from the transmitter start?

Only when the signal terminates at the receiver and an electrical circuit is closed

Upon voltage change in the transmitter

Depending on the type of the termination

Depending on whether the line is a stripline or a microstrip

#11 Characteristic impedance of transmission line depends mainly on

Transmitter voltage and current

The geometry of the cross-sectional area of the conductors and the materials of the transmission line

Copper resistivity

All the answers are correct

#12 What is the VIA impedance that will see a digital signal passing through?

Depends on the signal rise time

Depends on the VIA’s geometry (drill diameter, clearances, pads' diameter, NFP, etc.)

Depends on the signal voltage

Answers A and B are correct

#13 Narrowing the stripline/microstrip reference plane(s) will result in

An increase in characteristic impedance

A decrease in characteristic impedance

No change the characteristic impedance

Impossible to know

#14 The longer the transmission line, the characteristic impedance measured with TDR

Will decrease due to dielectric losses

Will increase due to the skin effect

Will decrease due to the proximity effect

Will not change

#15 Attenuation in the transmission line at [dB/in] will increase

Relative to the frequency root of both the dielectric and conductivity losses

Linear to the frequency from the dielectric losses and relative to the frequency root from the conductivity losses

Linear to the frequency of both the dielectric and conductivity losses

Relative to the frequency root of the dielectric losses and linear to the frequency from the conductivity losses

#16 Expected attenuation in [dB/GHz/in] in an FR4 transmission line is expected to be in the order of magnitude of

0.1-0.3

0.5-0.65

0.85-1

Above 1

#17 Due to cross-talk consideration between adjacent lanes: when routing large numbers of lanes parallelly, we will rout them

Non-interleaved in both stripline and microstrip transmission

Interleaved in both stripline and microstrip transmission

Non-interleaved in stripline transmission and interleaved in microstrip transmission

Interleaved in stripline transmission and non-interleaved in microstrip transmission

#18 The theoretical FEXT in the victim can reach

¾ of the aggressor’s voltage amplitude

½ of the aggressor’s voltage amplitude

¼ of the aggressor’s voltage amplitude

⅛ of the aggressor’s voltage amplitude

#19 When will Mode Conversion be created?

Anytime voltage in the P and N lines is not equal and opposite

Anytime there is asymmetry routing in lines P and N

Always – in every practical PCB

All the answers are correct

#20 Two lines whose single-ended impedance is 50 ohms are arranged such that the distance between them is H (where H is the distance between the line and its reference plane). What is likely to be the differential impedance of these lines?

Equal to 100 ohms

Greater than 100 ohms

Less than 100 ohms

Depends on other factors and therefore cannot be known

#21 Can a serpentine be used to correct a skew on a differential line that operates at tens of Gbps?

Yes, always

Yes, provided the differential line is very loosely coupled

Yes, provided the differential line is very tightly coupled

#22 On a PCB with multiple voltages, can each voltage plane be used as a reference plane for a transmission line

Yes, the reference plane functionality does not depend on its DC voltage

Reference planes must be GND only

Depends on the noise level on the supply plane

#23 What is the total jitter in a line where there is a deterministic jitter Dj and a random jitter with a standard deviation σ?

Dj + 14σ

14Dj + σ

7Dj + 7σ

The answer depends on the BER

#24 To what frequency can Power Delivery Network (PDN) impedance be maintained on the PCB below the Target Impedance with only decoupling capacitors (bulk and SMT) on the PCB?

Hundreds of kHz

A few MHz

Tens of MHz

Hundreds of MHz

finish

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Please fill in your details on the “Contact Us” page and a representative will get back to you.