CS4228A-KS Cirrus Logic, CS4228A-KS Datasheet - Page 19

• Manufacturer Part Number: CS4228A-KS
• Description: 24-Bit/ 96 kHz Surround Sound Codec
• Manufacturer: Cirrus Logic

The CS4228A will enter a stand-by mode if the
master clock source stops for approximately 10 s
or if the number of MCLK cycles per LRCK period
varies by more than 32. Should this occur, the con-
trol registers retain their settings.
The CS4228A will mute the analog outputs, assert
the MUTEC pin and enter the Power Down Mode
if the supply drops below approximately 4 volts.
3.10 Power Supply, Layout, and Grounding
The CS4228A requires careful attention to power
supply and grounding details. VA is normally sup-
plied from the system 5 VDC analog supply. VD is
from a 5 VDC digital supply, or for optimum ADC
performance, connect VD through a diode to a
+5 V supply to lower the digital core voltage. VL
should be from the supply used for the devices dig-
itally interfacing with the CS4228A. The power up
sequence of these three supply pins is not impor-
tant.
AGND and DGND pins should both be tied to a
solid ground plane surrounding the CS4228A. The
DS511PP1
system analog and digital ground planes should not
be separated under normal circumstances. A solid
ground plane underneath the part is recommended.
Decoupling capacitors should be mounted and
routed in such a way as to minimize the circuit path
length from the CS4228A supply pin or FILT pin,
through the capacitor, and back to the applicable
CS4228A AGND or DGND pin. The small value
ceramic capacitors should be closest to the part. In
some cases, ferrite beads in the VL, VD and VA
supply lines, and low-value resistances (~ 50
series with the LRCK, SCLK, SDIN and SDOUT
lines can help reduce coupling of digital signals
into the analog portions of the CS4228A.
The both capacitors on the FILT pin should be as
close to the CS4228A as possible. Any noise that
couples onto the FILT pin will couple directly onto
all of the analog outputs. Please see the CDB4228
evaluation board data sheet for recommended lay-
out of the decoupling components.
CS4228A
19
in