PCM1606

SLES014B − OCTOBER 2001 − REVISED AUGUST 2002

22

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APPLICATION INFORMATION

PCB layout guidelines

A typical PCB layout for the PCM1606 is shown in Figure 32. A ground plane is recommended, with the analog

and digital sections being isolated from one another using a split or cut in the circuit board. The PCM1606 should

be oriented with the digital I/O pins facing the ground plane split/cut to allow for short, direct connections to the

digital audio interface and control signals originating from the digital section of the board.

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 D/A converters. 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 33 shows

the recommended approach for single-supply applications.

Digital

Logic

and

Audio

Processor

Digital Power

+VD

DGND

Digital Section

Analog Section

Return Path for Digital Signals

Analog Power

+VS

AGND

−VS

+5VA

Digital

Ground

Analog

Ground

Output

Circuits

PCM1606

AGND

VCC

Figure 32. Recommended PCB Layout