Cirrus Logic CDB4384 - Manual (Page 4)

4 DS620DB1
CDB4384
source, remove the shunts on J15 and place a ribbon cable so the signal lines are on the center row and the grounds
are on the right side. R116 and R119 should be populated with 2 k
Ω resistors when using an external I
²
C source
which does not already provide pull-ups.
5. POWER SUPPLY CIRCUITRY
Power is supplied to the evaluation board by four binding posts (GND, +5V, +12V, and -12V), see Figure 10. The
‘+5V’ terminal supplies VA and the rest of the +5 V circuitry on the board. The +3.3 V circuitry is powered from a
regulator. The +2.5 V required for VD is also provided from an on-board regulator. The +5 V supply should be set
within the recommended values for VA stated in the CS4384 datasheet.
WARNING: Refer to the CS4384 datasheet for maximum allowable voltage levels. Operation outside of this range
can cause permanent damage to the device.
6. GROUNDING AND POWER SUPPLY DECOUPLING
As with any high-performance converter, the CS4384 requires careful attention to power supply and grounding ar-
rangements to optimize performance. Figure 2 details the connections to the CS4384 and Figures 11, 12, and 13
show the component placement and top and bottom layout. The decoupling capacitors are located as close to the
CS4384 as possible. Extensive use of ground plane fill in the evaluation board yields large reductions in radiated
noise.
7. ANALOG OUTPUT FILTERING
The analog output on the CDB4384 has been designed according to the CS4384 datasheet. This output circuit in-
cludes a passive 1-pole, 150 kHz filter with an AC coupled output.
Table 1. System Connections
CONNECTOR INPUT/OUTPUT SIGNAL PRESENT
+5V Input + 5 V power
GND Input Ground connection from power supply
+12V Input Unused
-12V Input Negative supply for the mute circuitry (-5 V to -12 V)
S/PDIF IN - J9 Input Digital audio interface input via coax
S/PDIF IN - OPT1 Input Digital audio interface input via optical
PCM INPUT - J11 Input Input for master, serial, left/right clocks and serial data
DSD INPUT - J7 Input Input for DSD serial clock and DSD data
OUTA1-B4 Output RCA line level analog outputs