DS633F1
73
CS44600
Signal to Noise Ratio (SNR)
SNR, similar to DR, is the ratio of an arbitrary sinusoidal input signal to the RMS sum of the noise floor, in
the presence of a signal. It is measured over a 20 Hz to 20 kHz bandwidth with units in dB.
SRC
Sample Rate Converter. Converts data derived at one sample rate to a differing sample rate. The CS44600
operates at a fixed sample frequency. The internal sample rate converter is used to convert digital audio
streams playing back at other frequencies to the PWM output rate.
Total Harmonic Dist Noise (THD+N)
The ratio of the rms value of the signal to the rms sum of all other spectral components over the specified
band width (typically 10 Hz to 20 kHz), including distortion components. Expressed in decibels. Measured
at -1 and -20 dBFS as suggested in AES17-1991 Annex A.
9. REFERENCES
1.
Cirrus Logic, “
Audio Quality Measurement Specification
,” Version 1.0, 1997.
http://www.cirrus.com/products/papers/meas/meas.html
2.
Cirrus Logic, “
AN18: Layout and Design Rules for Data Converters and Other Mixed Signal Devices
,”
Version 6.0, February 1998.
3.
Cirrus Logic, “
AN22: Overview of Digital Audio Interface Data Structures
,
Version 2.0
”, February 1998.; A
useful tutorial on digital audio specifications.
4.
Philips Semiconductor, “
The I²C-Bus Specification: Version 2
,” Dec. 1998.
http://www.semiconductors.philips.com