|Q||See Q Factor|
|Q Factor||A measure of the quality of a resonant (tank) circuit. A "high-Q" circuit has mostly reactive components (inductive and capacitive), with low resistance. It resonates strongly, with little damping (low loss). A high-Q circuit will have low bandwidth relative to its center frequency (that is, it will have a narrow bandwidth vs frequency curve).
Q = 2 π * (Energy stored / Energy dissipated per cycle)
|Q-Injection||See Charge Injection|
|Q-Pump||See Charge Pump|
|QAM||Quadrature Amplitude Modulation: A modulation method in which two signals are used to amplitude-modulate two carriers that are in quadrature (90 degrees out of phase with each other). The two modulated signals are combined.
A common application is in PAL and NTSC color television transmission. Color is encoded into two analog signals (called I and Q), which modulate quadrature color carriers.
Modems also use this approach, to increase the data bandwidth they can carry (or, more accurately, to trade bandwidth for error rate or noise immunity).
|QFN||"Quad, flat, no-lead" package.|
|QFP||Quad flat pack, a package type.|
See our QPSK tutorial: QPSK Modulation Demystified.
|QRSS||Quasi-random signal source|
|QS-9000||QS-9000 is the automotive quality standard surperseded by ISO/TS16949:2002 specification for component suppliers to the automotive industry.|
|QSOP||Quarter small-outline package|
|Quadrature||The relation between two waves of the same frequency, but one-quarter of a cycle (90°) out of phase.|
|Quadrature Amplitude Modulation||See QAM|
|Quadrature Modulation||See QAM|
|Quadrature Phase Shift Keying||See QPSK|
|Quadriphase Phase Shift Keying||See QPSK|
|Quality factor||See Q Factor|
|Quantization||A process whereby the continuous range of input-signal values is divided into nonoverlapping subranges. Each of these subranges has a discrete value of the output uniquely assigned. Once a signal value falls within a given subrange, the output provides the corresponding discrete value.|
|Quaternary Phase Shift Keying||See QPSK|
|QuERC||Software that examines bias and transient simulation output and flags devices operating above limits. Querc is supplied by Maxim to ASIC customers.|
|Quiescent||For an electronic circuit, a quiet state in which the circuit is driving no load and its inputs are not cycling. Most commonly used for the specification "quiescent current," the current consumed by a circuit when it in a quiescent state.|