SM5865CM Datasheet, PDF (14/20 Pages) Nippon Precision Circuits Inc – D/A Converter for Digital Audio

SM5865CM
Internal Oversampling Operation
The SM5865CM accepts data output from an 8-times or 4-times oversampling digital filter, and oversampled
internally again up to the noise shaper operating rate. The internal oversampling factor is determined automati-
cally from the system clock input frequency and the input sampling frequency. This internal oversampling fac-
tor (n) must be an integer satisfying the conditions shown in table 1.
Table 1. Operating conditions
Parameter
CKDVN = HIGH
CKDVN = LOW
f_WCKI and f_CKI compulsory conditions¹
f_CKI = f_WCKI × 8 × n
where n = 1, 2, 3, ...
f_CKI = f_WCKI × 16 × n
where n = 1, 2, 3, ...
Noise shaper operating frequency
f_ns
=
f_WCKI × n=
f---_C---K----I
8
f_ns
=
f_WCKI × n=
f---_C---K----I
16
1. f_WCKI = word clock frequency, f_CKI = input system clock frequency, n = internal oversampling factor
Word clock input
WCKI
SM5865CM
System clock input
CKI
System clock divider select
CKDVN
Figure 12. Clock-related inputs
NIPPON PRECISION CIRCUITS—14