Cirrus Logic CS4361 - Manual (Page 14)

14
CS4361
Confidential Draft
9/30/11
4.3 De-Emphasis
The CS4361 includes on-chip digital de-emphasis. Figure 11 shows the de-emphasis curve for Fs equal to
44.1 kHz. The frequency response of the de-emphasis curve will scale proportionally with changes in sam-
ple rate, Fs. The de-emphasis filter is active (inactive) if the DEM/SCLK pin is low (high) for five consecutive
falling edges of LRCK. This function is available only in the internal Serial Clock Mode when LRCK < 50 kHz.
4.4 Mode Select
Mode selection is determined by the Mode Select pin. The value of this pin is locked 1024 LRCK cycles after
RST is released. This pin requires a specific connection to supply, ground, MCLK, or LRCK as outlined in
Table 2 .
Table 2. Mode Pin Settings
Mode pin is: Mode Figure
Tied to VL I²S 7
Tied to GND Left-Justified 8
Tied to LRCK Right-Justified - 24 bit 9
Tied to MCLK Right-Justified - 16bit 10
LRCK
SCLK
Left Channel
Right Channel
SDATA 6 5 4 3 2 1 0 9 8 7 15 14 13 12 11 10 6 5 4 3 2 1 0 9 8 7 15 14 13 12 11 10
32 clocks
Internal SCLK Mode External SCLK Mode
Right-Justified, 16-Bit Data
INT SCLK = 32 Fs if
MCLK/LRCK = 1024, 512, 256, 128, or 64
INT SCLK = 48 Fs if
MCLK/LRCK = 768, 384, 192, or 96
INT SCLK = 72 Fs if
MCLK/LRCK = 1152 Right-Justified, 16-Bit Data
Data Valid on Rising Edge of SCLK
SCLK Must Have at Least 32 Cycles per LRCK Period
Figure 10. CS4361 Data Format (Right-Justified 16)
Gain
dB
-10dB
0dB
Frequency
T2 = 15 µs
T1=50 µs
F1 F2
3.183 kHz 10.61 kHz
Figure 11. De-Emphasis Curve (Fs = 44.1kHz)