OVERVIEW
The SM5846AP is a multi-function digital filter that incorporates 4/8 times oversampling digital audio signal reproduction, digital deemphasis, digital attenuation and soft mute functions. The I/O interface allows serial data transmission of 16/20/24/32-bit input data and 20/24-bit output data.

FEATURES
Functions
■ 8-times oversampling (interpolation)
■ Switchable 8/4 times oversampling output
■ Two master clock frequencies (refer to Clock Functions)
    • 384fs/512fs (normal-speed sampling)
    • 192fs/256fs (high-speed sampling)
■ Digital deemphasis
    • Compatible with 32/44.1/48 kHz (normal speed) and 64/88.2/96 kHz (high-speed) input sampling frequencies
    • ON/OFF control
■ Digital attenuator
    • 128-step attenuation using linear 7-bit data setting
■ Soft muting
    • 1016/fs (normal-speed sampling)
    • 2032/fs (high-speed sampling)
■ Output data round-off operation (normal round-off or rectangular distribution dither round-off)
■ Selectable LR clock polarity
■ Microprocessor controllable
■ Input data format
    • 2s complement, MSB first, alternating L/R serial
    • 16/20/24/32-bit data selectable
■ Output data format
    • 2s complement, MSB first, simultaneous L/R serial
    • 20/24-bit data selectable.
■ 24-bit internal data processing
■ Jitter-free mode/synchronous mode selectable
■ Crystal oscillator circuit built-in
■ TTL-compatible outputs
■ Molybdenum-gate CMOS

Filter Construction
■ Interpolation filter (linear 3-stage FIR filter)
    • Normal-speed sampling mode
        1st stage (fs to 2fs) 121st order
        2nd stage (2fs to 4fs) 21st order
        3rd stage (4fs to 8fs) 13th order
    • High-speed sampling mode:
        1st stage (fs to 2fs) 177th order
        2nd stage (2fs to 4fs) 29th order
        3rd stage (4fs to 8fs) 17th order
■ Deemphasis filter (IIR filter)
■ Arithmetic units
    • 25× 24-bit parallel adder
    • 32-bit accumulator
■ Overflow limiter built-in

APPLICATIONs
■ Digital audio equipment