CS4297 Datasheet, PDF (34/46 Pages) Cirrus Logic – CrystalClear SoundFusion Audio Codec 97

CS4297
CrystalClear™ SoundFusion™ Audio Codec ’97
PERFORMANCE PLOTS
Figures 11 through 26 show the overall Frequency
Response, the THD+N over frequency, and the DR
over frequency of the ADCs, the DACs, the analog
mixer (Line In to Line Out) and the microphone in-
puts. Crosstalk plots and the noise floor FFT plots
of the DACs, the analog mixer and the muted noise
floor of the CS4297 are also included. All plots
were taken on a CRD4297-1 with a CS4297-KQ
Codec.
Figures 11, 14, 17, and 20: The Frequency Re-
sponse plots were taken using a -20 dB FS input
signal swept over the frequency range of 20 Hz to
20 kHz and normalized to 0 dB at 1 kHz.
Figures 12, 15, 18, and 21: The THD+N plots were
taken using a -3 dB FS input signal swept over the
frequency range of 20 Hz to 20 kHz. These perfor-
mance plots used an “A”-weighted filter applied on
the output with the exception of the ADC THD+N
plot.
Figures 13, 16, 19, and 22: The Dynamic Range
plots were taken using a -50 dB FS input signal
swept over the frequency range of 20 Hz to 20 kHz.
These performance plots used an “A”-weighted fil-
ter applied on the output with the exception of the
ADC Dynamic Range plot.
Figure 23: The crosstalk plot was generated using a
0 dB FS input signal on one channel of the
LINE_IN input and measuring the magnitude of
the other output channel swept over the frequency
range of 20 Hz to 20 kHz. This performance plots
used an “A”-weighted filter applied on the output
Figures 24, 25, and 26: The noise floor plots were
generated by running a 16K-point FFT on the
LINE_OUT output with no input signal applied.
The Muted Noise Floor plot was taken with the
master mute bit ‘set’ (bit D15, register 0x02h).
These performance plots used an “A”-weighted fil-
ter applied on the output
All audio performance plots used unity gain set-
tings on the analog volume controls. Additionally,
the microphone input plots were taken with the +20
dB gain stage enabled (bit D6, register 0x0Eh).
The ADC plots used the A-D signal path. The DAC
plots used the D-A signal path. The mixer and the
microphone plots used the A-A signal path.
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