Cirrus Logic CDB4360 - Manual (Page 3)

CDB4360
DS517DB2 3
1. CDB4360 SYSTEM OVERVIEW
The CDB4360 evaluation board is an excellent
means of quickly evaluating the CS4360. The
CS8414 digital audio interface receiver provides an
easy interface to digital audio signal sources in-
cluding the majority of digital audio test equip-
ment. The evaluation board also allows the user to
supply clocks and data through a 10-pin header for
system development.
The CDB4360 schematic has been partitioned into
8 schematics shown in Figures 2 through 9. Each
partitioned schematic is represented in the system
diagram shown in Figure 1. Notice that the system
diagram also includes the interconnections be-
tween the partitioned schematics.
2. CS4360 DIGITAL TO ANALOG
CONVERTER
A description of the CS4360 is included in the
CS4360 datasheet.
3. CS8414 DIGITAL AUDIO RECEIVER
The system receives and decodes the standard
S/PDIF data format using a CS8414 Digital Audio
Receiver, Figure 3. The outputs of the CS8414 in-
clude a serial bit clock, serial data, left-right clock
(FSYNC), and a 256 x Fs master clock. The opera-
tion of the CS8414 and a discussion of the digital
audio interface are included in the CS8414
datasheet.
The evaluation board has been designed such that
the input can be either optical or coax, see Figure 3.
However, both inputs cannot be driven simulta-
neously.
The CS8414 data format is hard-wired to I
2
S.
4. INPUT/OUTPUT FOR CLOCKS AND
DATA
The evaluation board has been designed to allow
interfacing to external systems via the 10-pin head-
er, J24. This header allows the evaluation board to
accept externally generated clocks and data. The
schematic for the clock/data I/O is shown in
Figure 5.
5. POWER SUPPLY CIRCUITRY
Power is supplied to the evaluation board by six
binding posts (GND, +5 V, VLC, VLS, VD, and
VA), see Figure 9. The +5 V input supplies power
to the +5 Volt digital circuitry (VD_+5), while the
VLC input supplies power to the Voltage Level
Converters for the control port interface and the
CS4360 VLC pin. The VLS input supplies power
to the Voltage Level Converters for the serial audio
port interface and the CS4360 VLS pin. VA and
VD supply power to the CS4360. For ease of use,
it is possible to connect VLC, VLS, VD, and VA to
the same supply.
WARNING: VA and VD must be between +2.7V
and +5.5V. VLC and VLS must be between +1.7 V
and +5.5 V
. Operation outside of this range can
cause permanent damage to the device. See the
CS4360 datasheet for more details.
6. GROUNDING AND POWER SUPPLY
DECOUPLING
The CS4360 requires careful attention to power
supply and grounding arrangements to optimize
performance. Figure 2 details the power distribu-
tion used on this board. The decoupling capacitors
are located as close to the CS4360 as possible. Ex-
tensive use of ground plane fill on both the analog
and digital sections of the evaluation board yields
large reductions in radiated noise. See Figures 10-
12 for the CDB4360 PCB layout artwork.
7. CONTROL PORT SOFTWARE
The CDB4360 is shipped with Windows based
software for interfacing with the CS4360 control
port via the parallel connector, J28. The software
can be used to communicate with the CS4360 in
SPI or Two Wire mode. Note: J18-J21 must be set
appropriately for control port mode operation.