CS4812
only one supply is available, use the suggested ar-
rangement in Figure 5.
4. POWER SUPPLY AND GROUNDING
Proper layout and grounding is critical to obtaining
optimal audio performance in your system. The
A single solid ground plane is the simplest ground-
most important rule to remember is to not allow ing scheme that works well in many cases. All an-
currents from digital circuitry to couple into sensi- alog and digital grounds shown in Figure 5 should
tive analog circuitry. This is generally done by us- be tied to the one plane.
ing a separate or filtered power supply for the
Decoupling capacitors should be placed as close as
analog circuitry, physically separating the analog
and digital components and traces in the pcb layout
and using wide traces or planes for ground and
power. One misplaced component or trace can se-
verely degrade overall system performance.
possible to the device with the lowest value capac-
itor closest to the chip. Any power and ground con-
nection vias should be placed near their respective
component pins and should be attached directly to
the appropriate plane. If traces are used for the
When using separate supplies, the analog and digi- power supplies to the CS4812, they should be as
tal power should be connected to the CS4812 via a
ferrite bead, positioned closer than 1" to the device
(see Figure 21). The CS4812 VA pin should be de-
rived from the quietest power source available. If
wide as possible to maintain low impedance.
It is recommended to solder the CS4812 directly to
the printed circuit board. Soldering improves per-
formance and enhances reliability
>
1/8"
Digital
Power
Plane
Note that the CS4812
is oriented with its
digital pins towards the
digital end of the board.
Ferrite
Bead
CS4812
Analog
Power
Plane
Digital Interface
Analog Signals &
Components
Figure 27. CS4812 Suggested Layout
28
DS291PP3
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