Cirrus Logic CS4385A - Manual (Page 28)

28 DS837F2
CS4385A
4.9 Grounding and Power Supply Arrangements
As with any high-resolution converter, the CS4385A requires careful attention to power supply and ground-
ing arrangements if optimal potential performance levels are to be realized. The Typical Connection Dia-
gram shows the recommended power arrangements, with VA, VD, VLC, and VLS connected to clean
supplies. If the ground planes are split between digital ground and analog ground, the GND pins of the
CS4385A should be connected to the analog ground plane.
Note: All signals, especially clocks, should be kept away from the FILT+ and VQ pins in order to avoid
unwanted coupling into the DAC.
4.9.1 Capacitor Placement
Decoupling capacitors should be placed as close to the DAC as possible, with the low value ceramic ca-
pacitor being the closest. To further minimize impedance, these capacitors should be located on the same
layer as the DAC. If desired, all supply pins with similar voltage ratings may be connected to the same
supply, but a decoupling capacitor should still be placed on each supply pin.
Note: All decoupling capacitors should be referenced to ground.
BCKA
(128Fs)
BCKD
(64Fs)
DSD_SCLK
DSDAx,
DSDBx
D1 D1
D1 D0 D2
D2 D0
DSD_SCLK
DSDAx,
DSDBx
BCKA
(64Fs)
DSD_SCLK
DSD Phase
Modulation Mode
DSD Normal Mode
Not Used
Not Used
Not Used
Figure 21. DSD Phase Modulation Mode Diagram