OVERVIEW

The SM5847AF is a 4/8-times oversampling (inter polation), 2-channel, linear-phase FIR, multi-function digital filter for digital audio reproduction equipment. It features independent left and right channel digital deemphasis filters and soft muting function.

FEATURES

■ Left/right-channel (2-channel processing)

■ 4-times/8-times oversampling (interpolation)

• 8-times interpolation filter

- 3-stage linear-phase FIR configuration

1st stage (fs to 2fs): 169-tap

2nd stage (2fs to 4fs): 29-tap

3rd stage (4fs to 8fs): 17-tap

- ≤±0.00002 dB passband ripple (0 to 0.4535fs)

- ≥117 dB stopband attenuation (0.5465fs to 7.4535fs)

• 4-times interpolation filter

- 2-stage linear-phase FIR configuration

1st stage (fs to 2fs): 169-tap

2nd stage (2fs to 4fs): 29-tap

- ≤±0.00002 dB passband ripple (0 to 0.4535fs)

- ≥116 dB stopband attenuation (0.5465fs to 3.4535fs)

■ Digital deemphasis

• IIR filter configuration

• fs = 32kHz, 44.1kHz, 48kHz

• 2-channel independent ON/OFF control

■ 26 ×24-bit parallel multiplier/32-bit accumulator

■ Overflow limiter

■ Soft muting

• 2-channel independent ON/OFF control

■ Input data format

• 2s complement, MSB first

• 3 selectable formats

- LR alternating, 16/18/20/24-bit serial, righ justified data

- LR alternating, 24-bit serial, left-justifie data

- LR simultaneous, 24-bit serial, left-justifie data

■ Output data format

• 2s complement, MSB first, LR simultaneous

• 18/20/22/24-bit serial

• BCKO burst (NPC format)

■ Dither round-off processing

• Dither round-off ON/OFF selectable

■ 25-bit internal data word length

■ Internal system clock

• 192fs/256fs selectable

• Maximum operating frequency

192fs mode: 37 MHz max (5 V)

20.7 MHz max (3 V)

256fs mode: 27.6 MHz max (5 V)

25 MHz max (3 V)

■ Jitter-free function

• Jitter-free/Sync mode selectable

■ Crystal oscillator circuit built-in

■ 3 to 5 V supply

■ 44-pin plastic QFP

■ CMOS process