CS4215 Datasheet, PDF (36/52 Pages) Cirrus Logic – 16-Bit Multimedia Audio Codec

PARAMETER DEFINITIONS
CS4215
Resolution
The number of bits in the input words to the DACs, and in the output words in the ADCs.
Differential Nonlinearity
The worst case deviation from the ideal codewidth. Units in LSB.
Total Dynamic Range
The rms value of a full scale signal to the lowest obtainable noise floor. It is measured by
comparing a full scale signal to the lowest noise floor possible in the codec (ie. attenuation bits
for the DACs at full attenuation.) Units in dB.
Instantaneous Dynamic Range
The dynamic range available at any instant in time. It is measured using S/(N+D) with a 1 kHz,
-60 dB input signal, with 60 dB added to compensate for the small input signal. Use of a small
input signal reduces to harmonic distortion components of the noise to insignificance. Units in
dB.
Total Harmonic Distortion
THD is the ratio of the rms value of a signal’s first five harmonic components to the rms value
of the signals fundamental component. THD is calculated for the ADCs using an input signal
which is 3dB below typical full-scale, and is referenced to typical full-scale. A digital full-scale
output is used to calculate THD for the DACs.
Interchannel Isolation
The amount of 1 kHz signal present on the output of the grounded input channel with 1 kHz
0 dB signal present on the other channel. Units in dB.
Interchannel Gain Mismatch
For the ADCs, the difference in input voltage that generates the full scale code for each
channel. For the DACs, the difference in output voltages for each channel with a full scale
digital input. Units in dB.
Frequency Response
Worst case variation in output signal level versus frequency over 10 Hz to 20 kHz. Units in dB.
Step Size
Typical delta between two adjacent gain or attenuation values. Units in dB.
Absolute Step Error
The deviation of a gain or attenuation step from a straight line passing through the
no-gain/attenuation value and the full-gain/attenuation value (i.e. end points). Units in dB.
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