|
otázka |
odpověď |
What is the significance of the band gap in semiconductors? začněte se učit
|
|
It defines the energy required to move electrons from the valence band to the conduction band, enabling conductivity.
|
|
|
What is the Early effect in BJTs? začněte se učit
|
|
A variation in collector current due to changes in collector-base voltage, resulting in output conductance.
|
|
|
What does the Miller effect refer to? začněte se učit
|
|
The apparent increase in input capacitance due to amplification of feedback capacitance in inverting amplifiers.
|
|
|
What is channel-length modulation in MOSFETs? začněte se učit
|
|
A decrease in effective channel length with increased drain voltage, leading to increased drain current.
|
|
|
What is transconductance (gm) in a MOSFET? začněte se učit
|
|
It is the rate of change of drain current with respect to gate-source voltage, gm = dId/dVgs.
|
|
|
What is a differential pair used for? začněte se učit
|
|
To amplify the difference between two input signals while rejecting common-mode signals.
|
|
|
What is the gain-bandwidth product of an op-amp? začněte se učit
|
|
It is the frequency at which the open-loop gain drops to unity; a key performance parameter.
|
|
|
|
začněte se učit
|
|
A graph representing the gain and phase of a system as a function of frequency, used for stability and frequency response analysis.
|
|
|
What is the Nyquist criterion for stability? začněte se učit
|
|
A graphical condition that ensures closed-loop stability by avoiding encirclements of the −1 point in the Nyquist plot.
|
|
|
What is a pole in a transfer function? začněte se učit
|
|
A value of s where the system's response becomes infinite, related to natural frequencies and stability.
|
|
|
What is a zero in a transfer function? začněte se učit
|
|
A frequency at which the system's output is zero despite input; used to shape response.
|
|
|
What is slew rate limiting in op-amps? začněte se učit
|
|
A non-linear phenomenon where the output cannot change faster than a maximum rate, causing distortion.
|
|
|
What does negative feedback achieve in amplifiers? začněte se učit
|
|
It increases linearity, reduces gain, enhances bandwidth, and improves stability.
|
|
|
|
začněte se učit
|
|
The difference between the phase shift and -180° at the unity gain frequency; indicates stability.
|
|
|
What is thermal runaway in BJTs? začněte se učit
|
|
A positive feedback condition where increased temperature leads to increased current and further heating, potentially destroying the transistor.
|
|
|
What is a hysteresis loop in a Schmitt trigger? začněte se učit
|
|
A voltage range where input changes don't affect output, used to eliminate noise-induced switching.
|
|
|
What is a Class AB amplifier's advantage over Class B? začněte se učit
|
|
It combines high efficiency with minimal crossover distortion.
|
|
|
What is a phase-locked loop (PLL)? začněte se učit
|
|
A feedback system that locks the phase of an output signal to a reference, used in frequency synthesis and clock recovery.
|
|
|
What is the Barkhausen criterion? začněte se učit
|
|
A condition for oscillation stating that the loop gain must be unity and the total phase shift must be 0 or 360°.
|
|
|
What is parasitic capacitance? začněte se učit
|
|
Unintended capacitance that occurs between parts of an electronic component or circuit due to proximity and layout.
|
|
|
