Dictionary Q

quantization error, inherent (of an ideal analog-to-digital converter)

Within a step, the maximum (positive or negative) possible deviation of the actual analog input value from the nominal midstep value.

NOTE 1 This error follows necessarily from the quantization procedure. For a linear analog-to-digital converter, its value equals ±½ LSB.

NOTE 2 Use of the term "resolution error" in place of "inherent quantization error" is deprecated, because "resolution" as a design parameter has a nominal value only.

References:

JESD99B, 5/07

quantum efficiency (of a photosensitive device)

The ratio of the number of effective electron-hole pairs produced within the device to the number of incident photons.

NOTE For devices that internally amplify or multiply the electron‑hole pairs (such as phototransistors or avalanche photodiodes), the effect of the gain is to be excluded from quantum efficiency.

References:

JESD77-B, 2/00

quantum efficiency, external (of a photoemitter)

The ratio of the number of photons radiated to the number of electrons flowing into the radiation source.

References:

JESD77-B, 2/00

quantum efficiency, internal (of a photoemitter)

The ratio of the number of photons internally produced to the number of electrons flowing into the radiation source.

References:

JESD77-B, 2/00

quiescent current

The dc current through a terminal when no signal is applied.

References:

JESD99A.01, 5/0

quiescent output voltages (VO)

The dc voltage at an output terminal with reference to a common terminal, normally ground, when no signal is applied to the input.

References:

JESD99B, 5/07

quiescent voltage

The dc voltage at a terminal when no signal is applied.

References:

JESD99B, 5/07

quoted failure rate (λq)

The predicted failure rate for typical operating conditions.

NOTEThe quoted failure rate is calculated from the observed failure rate under accelerated stress conditions multiplied by an acceleration factor; e.g., λq = λo AT, where λq is the quoted (predicted) system failure rate at some system temperature Ts, λo is the observed failure rate at some test temperature Tt, and AT is the temperature acceleration factor from Tt to Ts. When multiple failure mechanisms and thus multiple acceleration factors are involved, then a proper summation technique, e.g., sum-of-the-failure-rates method, is required.

References:

JEP122E, 3/09
JEP143B.01, 6/08

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