Datasheet

PCM1753
PCM1754
PCM1755
SLES092C – OCTOBER 2003 – REVISED FEBRUARY 2009
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27
Digital Logic
and
Audio
Processor
Digital Power
+V
D
DGND
Digital Section Analog Section
Return Path for Digital Signals
Analog Power
+V
S
AGND –V
S
+5VA
Digital
Ground
Analog
Ground
Output
Circuits
PCM1753/54/55
AGND
V
CC
DGND
Figure 30. Recommended PCB Layout
Separate power supplies are recommended for the digital and analog sections of the board. This prevents the
switching noise present on the digital supply from contaminating the analog power supply and degrading the
dynamic performance of the PCM1753/54/55. In cases where a common 5-V supply must be used for the
analog and digital sections, an inductance (RF choke, ferrite bead) should be placed between the analog and
digital 5-V supply connections to avoid coupling of the digital switching noise into the analog circuitry. Figure 31
shows the recommended approach for single-supply applications.
V
DD
Digital Section Analog Section
RF Choke or Ferrite Bead
Power Supplies
Common
Ground
Output
Circuits
AGND
V
CC
+V
S
+5V –V
S
AGND
DGND
PCM1753/54/55
Figure 31. Single-Supply PCB Layout