PCM1600 Burr-Brown Corporation, PCM1600 Datasheet - Page 28

• Manufacturer Part Number: PCM1600
• Description: 24-Bit/ 96kHz Sampling/ 6-Channel/ Enhanced Multi-Level/ Delta-Sigma DIGITAL-TO-ANALOG CONVERTER
• Manufacturer: Burr-Brown Corporation

to 24-bit audio word length and a sampling frequency of
44.1kHz, or 96kHz. The digital generator output is taken
from the unbalanced S/PDIF connector of the measurement
system. The S/PDIF data is transmitted via coaxial cable to
the digital audio receiver on the DEM-DAI1600 demo board.
The receiver is then configured to output 24-bit data in either
I
format is programmed to match the receiver output format.
The analog output is then taken from the DAC post filter and
connected to the analog analyzer input of the measurment
system. The analog input is band limited using filters resi-
dent in the analyzer. The resulting THD+N is measured by
the analyzer and displayed by the measurement system.
DYNAMIC RANGE
Dynamic range is specified as A-Weighted, THD+N mea-
sured with a –60dBFS, 1kHz digital sine wave stimulus at
the input of the D/A converter. This measurment is designed
to give a good indicator of how the DAC will perform given
a low-level input signal.
FIGURE 22. Test Setup for THD+N Measurements.
FIGURE 23. Test Set-Up for Dynamic Range and SNR Meeasurements.
2
S or left-justified data format. The DAC audio interface
NOTES: (1) Infinite Zero Detect Mute disabled.
(2) Results without A-Weighting will be
approximately 3dB worse.
NOTES: (1) There is little difference
in measured THD+N when using the
various settings for these filters.
(2) Required for THD+N test.
®
PCM1600, PCM1601
S/PDIF
Output
S/PDIF
Output
(Dynamic Range)
Dither Off (SNR)
1kHz Sine Wave
0% Full Scale,
–60dBFS,
Generator
Digital
100% Full Scale
24-Bit, 1kHz
Sine Wave
Generator
Digital
RMS Mode
Analyzer
Display
and
Evaluation Board
28
DEM-DAI1600
Evaluation Board
The measurement setup for the dynamic range measurement
is shown in Figure 23, 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 –60dBFS input level.
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 0’s data, and the
D/A converter’s Infinite Zero Detect Mute function must
be disabled (default condition at power up for the PCM1600,
PCM1601). This ensures that the delta-sigma modulator
output is connected to the output amplifier circuit so that
idle tones (if present) can be observed and effect the SNR
measurement. The dither function of the digital generator
must also be disabled to ensure an all ‘0’s 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 notes provided in Figure 23).
RMS Mode
Analyzer
Receiver
DEM-DAI1600
Display
S/PDIF
and
Receiver
S/PDIF
A-Weight
Filter
(1)
Option = 20kHz Apogee Filter
HPF = 22Hz
LPF = 30kHz
Band Limit
PCM1600
PCM1601
Option = A-Weighting
HPF = 22Hz
LPF = 22kHz
PCM1600
Band Limit
PCM1601
(1)
(1)
(1)
f
–3dB
Notch Filter
2nd-Order
Low-Pass
f
C
Filter
(2)
= 1kHz
= 54kHz
(2)
f
–3dB
Notch Filter
2nd-Order
Low-Pass
f
C
Filter
= 1kHz
= 54kHz