SM5842AP Datasheet, PDF (1/23 Pages) Nippon Precision Circuits Inc – High-Class Audio Multi-function Digital Filter

NIPPON PRECISION CIRCUITS INC.
SM5842AP/APT
High-Class Audio Multi-function Digital Filter
OVERVIEW
The SM5842AP/APT is a multi-function digital filter
IC, fabricated using NPC’s Molybdenum-gate
CMOS process, for digital audio reproduction equip-
ment. It features 8-times oversampling (interpola-
tion), independent left and right-channel digital
deemphasis, and soft muting functions. It accepts 16,
18, 20 or 24-bit input data, and outputs data in 18,
20, 22 or 24-bit format. It operates using either a
384fs or 256fs system clock at sampling frequencies
up to 48 kHz + 10% (384fs SM5842AP, 384/256fs
SM5842APT).
FEATURES
Functions
s L/R 2-channel processing
s 8-times oversampling (interpolation)
• ≤ ±0.00002 dB passband ripple
• ≥ 117 dB stopband attenuation
s Digital deemphasis
• 32/44.1/48 kHz sampling frequency (fs)
• 2-channel independent ON/OFF control
s Soft muting
• 2-channel independent ON/OFF control
s Input data format
• 2s complement, MSB first
- LR alternating, 16/18/20/24-bit serial, trail-
ing data
- LR alternating, 24-bit serial, leading data
- LR simultaneous, 24-bit serial, leading data
s Output data format
• 2s complement, MSB first, LR simultaneous
• 18/20/22/24-bit serial
• BCKO burst (NPC format)
s Dither round-up processing
• ON (dither rounding)/OFF (normal rounding)
control
s 25-bit internal data length
s Jitter-free function for correct operation in the
presence of jitter between the system clock and
LRCI clock
• ON (jitter-free mode)/OFF (sync mode) control
s 256fs/384fs system clock selectable
• 384fs
- 21.2 MHz maximum frequency (at maximum
fs = 55.2 kHz)
• 256fs
- 13 MHz maximum frequency (at maximum
fs = 50.7 kHz, SM5842AP)
- 14.2 MHz maximum frequency (at maximum
fs = 55.2 kHz, SM5842APT)
s Crystal oscillator circuit built-in
s TTL-compatible input/outputs
s 5.0 ± 0.25 V supply
s Molybdenum-gate CMOS process
s 28-pin plastic DIP
Filter Configuration
s Linear phase 3-stage FIR interpolation filter
• 169-tap 1st stage (fs to 2fs)
• 29-tap 2nd stage (2fs to 4fs)
• 17-tap 3rd stage (4fs to 8fs)
s Deemphasis filter
- IIR filter configuration for accurate gain and
phase characteristics
s 26 × 24-bit parallel multiplier/32-bit accumulator
for high precision
s Overflow limiter built-in
APPLICATIONS
s CD players
s DAT players
s PCM systems
PINOUT
DI / INF2N
1
BCKI
CKSLN
INF1N
IW1N / DIL
XTI
XTO
VSS
CKO
IW2N / DIR
OW1N
OW2N
SYNCN
RSTN 14
28
LRCI
DG
BCKO
WCKO
DOL
DOR
VDD
DITHN
MUTEL
MUTER
FSEL2
FSEL1
DEMPL
15
DEMPR
NIPPON PRECISION CIRCUITS—1