CS4228 Datasheet, PDF (28/30 Pages) Cirrus Logic – 24-Bit, 96 kHz Surround Sound Codec

CS4228
PARAMETER DEFINITIONS
Dynamic Range
The ratio of the full scale RMS value of the signal to the RMS sum of all other spectral
components over the specified bandwidth. Dynamic range is a signal-to-noise measurement
over the specified bandwidth made with a -60 dbFs signal. 60 dB is then added to the resulting
measurement to refer the measurement to full scale. This technique ensures that the distortion
components are below the noise level and do not effect the measurement. This measurement
technique has been accepted by the Audio Engineering Society, AES17-1991, and the
Electronic Industries Association of Japan, EIAJ CP-307.
Total Harmonic Distortion + Noise
The ratio of the RMS value of the signal to the RMS sum of all other spectral components over
the specified bandwidth (typically 20 Hz to 20 kHz), including distortion components.
Expressed in decibels. ADCs are measured at -1dBFs as suggested in AES 17-1991 Annex A.
Idle Channel Noise / Signal-to-Noise-Ratio
The ratio of the RMS analog output level with 1 kHz full scale digital input to the RMS analog
output level with all zeros into the digital input. Measured A-weighted over a 10 Hz to 20 kHz
bandwidth. Units in decibels. This specification has been standardized by the Audio
Engineering Society, AES17-1991, and referred to as Idle Channel Noise. This specification has
also been standardized by the Electronic Industries Association of Japan, EIAJ CP-307, and
referred to as Signal-to-Noise-Ratio.
Total Harmonic Distortion (THD)
THD is the ratio of the test signal amplitude to the RMS sum of all the in-band harmonics of
the test signal. Units in decibels.
Interchannel Isolation
A measure of crosstalk between channels. Measured for each channel at the converter’s output with
no signal to the input under test and a full-scale signal applied to the other channel. Units in decibels.
Frequency Response
A measure of the amplitude response variation from 20Hz to 20 kHz relative to the amplitude
response at 1 kHz. Units in decibels.
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 are in decibels.
Gain Error
The deviation from the nominal full scale output for a full scale input.
Gain Drift
The change in gain value with temperature. Units in ppm/°C.
Offset Error
For the ADCs, the deviation in LSBs of the output from mid-scale with the selected input
grounded. For the DACs, the deviation of the output from zero (relative to CMOUT) with mid-
scale input code. Units are in volts.
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