Auto Rate Detect; Emphasis; Figure 23.De-Emphasis Curve - Cirrus Logic CS44600 Manual

4.4.2

Auto Rate Detect

The CS44600 will automatically determine the incoming sample rate, DAI_LRCK, to master clock,
DAI_MCLK, ratio and configure the appropriate internal clock divider such that the sample rate convertor
receives the required clock rate. A minimum DAI_MCLK rate of 128Fs is required for proper operation.
The supported DAI_MCLK to DAI_LRCK ratios are shown in
4.4.3 De-Emphasis
The CS44600 includes on-chip digital de-emphasis filters. The de-emphasis feature is included to accom-
modate older audio recordings that utilize pre-emphasis equalization as a means of noise reduction.
Figure 23 shows the de-emphasis curve. The frequency response of the de-emphasis curve will scale pro-
portionally with changes in sample rate, Fs. The required de-emphasis filter for 32 kHz, 44.1 kHz, or
48 kHz is selected via the de-emphasis control bits in
30
Gain
dB
T1=50 µs
0dB
-10dB
F1
3.183 kHz
Figure 23. De-Emphasis Curve
Table 1 on page
"Misc. Configuration (address 04h)" on page
T2 = 15 µs
F2 Frequency
10.61 kHz
CS44600
26.
52.
DS633F1