PCM1753
PCM1754
PCM1755
SLES092A – OCTOBER 2003 – REVISED AUGUST 2004
www.ti.com
Dynamic Range
Dynamic range is specified as A-weighted THD+N measured with a –60-dB full-scale, 1-kHz digital sine wave
stimulus at the input of the D/A converter. This measurement is designed to give a good indicator of how the
DAC performs given a low-level input signal.
The measurement setup for the dynamic range measurement is shown in Figure 37, and is similar to the
THD+N test setup discussed previously. The differences include the band limit filter selection, the additional
A-weighting filter, and the –60-dB full-scale input level.
Evaluation Board
DEM-DAI1753
2nd-Order
S/PDIF
PCM1753/54/55
Low-Pass
Filter
Receiver
f
= 54 kHz or 108 kHz
–3 dB
Audio Precision System Two
Analyzer
and
Display
Digital
Generator
AES17 Filter
Band Limit
S/PDIF
Output
0 dB FS
(100% Full-Scale),
24-Bit,
Averaging
Mode
HPF = 400 Hz
LPF = 30 kHz
f
= 20.9 kHz
–3 dB
1-kHz Sine Wave
Figure 36. Test Setup for THD+N Measurement
Idle Channel Signal-to-Noise Ratio
The SNR test provides a measure of the noise floor of the D/A converter. The input to the D/A is all-0s data,
and the dither function of the digital generator must be disabled to ensure an all-0s data stream at the input of
the D/A converter.
The measurement setup for SNR is identical to that used for dynamic range, with the exception of the input
signal level.
(See the note provided in Figure 37).
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