5.0 V
4.125 V
VA
AOUTx+
AOUTx-
2.5 V
2.5 V
0.875 V
4.125 V
0.875 V
Full-Scale Differential Output Level =
(AOUTx+) - (AOUTx-) = 6.5 VPP = 2.3 VRMS
Figure 12. Full-Scale Output
5.3.3 Digital Volume Control
Hardware Mode
DAC Volume Control and Mute are not accessible in Hardware Mode.
Software Mode
Each DAC’s output level is controlled via the Volume Control registers operating over the range
of 0 to -127.5 dB attenuation with 0.5 dB resolution. See “AOUTX Volume Control (addresses
08h- 0Fh)” on page 48. Volume control changes are programmable to ramp in increments of
0.125 dB at the rate controlled by the SZC[1:0] bits in the Digital Volume Control register. See
“Transition Control (address 06h)” on page 46.
Each output can be independently muted via mute control bits in the register “DAC Channel
Mute (address 07h)” on page 48. When enabled, each AOUTx_MUTE bit attenuates the corre-
sponding DAC to its maximum value (-127.5 dB). When the AOUTx_MUTE bit is disabled, the
corresponding DAC returns to the attenuation level set in the Volume Control register. The at-
tenuation is ramped up and down at the rate specified by the SZC[1:0] bits.
5.3.4 De-Emphasis Filter
The CS42438 includes on-chip digital de-emphasis optimized for a sample rate of 44.1 kHz. The
filter response is shown in Figure 13. The de-emphasis feature is included to accommodate au-
dio recordings that utilize 50/15 µs pre-emphasis equalization as a means of noise reduction.
32
DS646PP2
CIRRUS [ CIRRUS LOGIC ]
