SM5842AP Datasheet, PDF (13/23 Pages) Nippon Precision Circuits Inc – High-Class Audio Multi-function Digital Filter

SM5842AP/APT
Soft Muting
Muting of the left and right channel is controlled
independently by MUTEL and MUTER, respec-
tively. Muting is ON when MUTEL/MUTER is
HIGH, muting is OFF when MUTEL/MUTER is
LOW.
When MUTEL/MUTER goes HIGH, the attenuation
changes smoothly from 0 to −∞ dB in 512/fs, or
System Clock (XTI, XTO, CKO, CKSLN)
Two system clock frequencies, 384fs and 256fs, can
be used. An external clock source can be input on
XTI, or a crystal oscillator can be constructed by
connecting a crystal between XTI and XTO. The
system clock is also buffered and then output on
CKO. The system clock frequency selection and the
internal clock frequency are shown in table 2.
approximately 11.6 ms when fs = 44.1 kHz. When
MUTEL/MUTER goes LOW, muting is released and
the attenuation changes smoothly from −∞ to 0 dB,
again taking approximately 11.6 ms.
When RSTN goes LOW, the DOL and DOR outputs
go LOW, immediately muting the output signal.
Muting is released and timing is synchronized when
RSTN goes HIGH.
Table 2. System clock frequency select
Parameter
XTI input clock frequency (f_XI = 1/t_XI)
CKO clock frequency
Internal clock frequency (t_SYS)
CKSLN
HIGH
LOW
384fs
256fs
384fs
256fs
2 × t_XI
t_XI
CKSLN
XTI
XTO
CKO
To timing controller
1/2
Internal system clock
(192fs or 256fs)
Figure 2. Clock generator circuit
NIPPON PRECISION CIRCUITS—13