Evaluation Module User's Guide

4.3 Recording Performance
PC
Recordingatf =44.1kHzbyapplicationsoftware
(forexample,SoundRecorder,QuickTime,etc.)
S
USB
Connector
D2 D1
SW1
JP1
J1
JP2
J2
100mA
0dB
PCM2912A
PCM2912A-EVM
Mic
Headphone
AudioPrecision
SYS-2722
AnalogGenerator
Unbalanced
FloatingGNDsetting
AudioPrecision
SYS-2722
DigitalAnalyzer
PC
Volumegain=0dB
USB
Connector
DEM-PCM2704EVM
S/PDIF
Output
Recording Performance www.ti.com
The DEM-PCM2912A EVM playback performance presented in this section was obtained under the
following conditions:
• f
S
= 44.1 kHz
• Input PGA (Microphone input volume): 0 dB
• Jumper setting: set JP1 to 100 mA and JP2 to 0 dB
• Application software for playback: Sound Recorder, Media Player and ITunes for Windows Vista/XP;
QuickTime and ITunes for Mac OS X.
• Use analog input data provided by the AP2 analog generator (SYS-2722) with unbalanced floating
ground setting.
Configure the equipment as shown in Figure 4-2 .
Figure 4-2. DEM-PCM2912A EVM Configuration for Recording Performance Measurement when
Recording Data
To measure recording performance with the recording data, use S/PDIF digital interface output data.
Connect the EVM to the AP2 digital analyzer (SYS-2722); for example, as the DEM-PCM2704 EVM
shown in Figure 4-3 .
Figure 4-3. DEM-PCM2704EVM Configuration for Recording Performance Measurement with Recorded
Data
Table 4-4. Line Input Recording Performance
Power Supply Performance Filter Setting DOUT
5.0 V THD+N (–1 dB at 1 kHz) 400 Hz to 20 kHz LP 0.008%
SNR (BPZ input) 400 Hz to 20 kHz LP 92.5 dB
+ A-weighting
DR (–60 dB input) 400 Hz to 20 kHz LP 90.5 dB
+ A-weighting
Evaluation and Measurements36 SBAU141 – January 2009
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