Many PCBs now operate at digital signal frequencies of 10 GHz and higher, which means that appropriate measures are needed to prevent unacceptable signal degradation and their consequential errors. How much do you know about signal integrity? Take the quiz to find out!
#1 How is the rise time of a signal often measured?
By calculating the signal knee frequency.
By calculating the degree of signal distortion.
By calculating the maximum data transmission rate.
#2 What do changes in the impedance that a signal sees cause?
#3 What is the best thing to do if you want to increase the capacitance of a via?
Increase the drill diameter.
Increase the pad size.
Increase the number of power planes.
#4 What is not true about propagation delays?
Signal skew causes signal sampling errors, particularly at high clock frequencies.
Signals that travel different distances do not arrive at their destination at the same time.
Signals that travel through different mediums arrive at their destination at the same time.
#5 Which of the following is not a step to mitigate signal degradation?
Increasing the effects of propagation delay.
Matching the impedance of the source, receiver, and signal traces.
#6 Where does the electric signal travel fastest?
In a microstrip without soldermask.
In a stripline with high dielectric material.
In a stripline with low dielectric material.
#7 What does signal attenuation lead to?
Decrease in the possibility of data errors.
Quick signal rise times.
Slow signal rise times.
#8 How can you minimize supply voltage fluctuations?
By keeping all leads long and avoiding the use of decoupling capacitors.
By using power and ground planes mounted on the outer PCB layers.
By covering as less surface area as possible.
#9 What is the definition of crosstalk?
The attenuation of a signal caused by the resistance of PCB traces and the board’s dielectric dissipation factor.
Rapid voltage and current transitions inducing voltages in adjacent traces due to inductive and capacitive coupling.
A degree of signal distortion that is related to the frequency response of the circuit.
#10 What can you do to reduce crosstalk?
Maximize the distance between signal traces and use wide return paths.
Split the return paths and use high dielectric material in the PCB construction.
Avoid using differential signaling, which is more sensitive to the effects of cross talk.
#11 Distance D spaces a pair of microstrip traces apart, and H is the separation from the ground plane. Which of the following generates greatest amount of cross talk?
D = 3 mils and H = 4 mils
D = 8 mils and H = 6 mils
D = 4 mills and H = 8 mils
#12 How can you minimize signal attenuation?
By using high-loss dielectric materials.
By using low-loss dielectric materials.
By using high resistance traces.