OVERVIEW

The SM5844AF is a digital audio signal, asynchronous sample rate converter LSI. It reads 16 or 20-bit word length input data, and writes 16, 18, or 20-bit word length output data. It also features a built-in digital deemphasis filter and digital attenuator.

The SM5844AF operates from a 5 V supply, and is available in 44-pin QFPs.

FEATURES

Functions

■ Left/right-channel processing (stereo)

■ Input sample rate (fsi) ranges

? 24 to 48 kHz (256fsi mode)

? 27 to 55 kHz (384fsi mode)

■ Output sample rate (fso) range

? 20 to 100 kHz

■ Sample rate conversion ratio (fso/fsi)

? 0.5 to 2.0 times

■ Asynchronous input and output timing (clock inputs)

■ System clock inputs (input and output clocks independent)

? 256fsi or 384fsi input system clock

? 256fso or 384fso output system clock

■ Deemphasis filter

? IIR-type filter

? 44.1, 48 or 32 kHz

■ Digital attenuator

? 11-bit data for 1025 levels

? Smooth, incremental attenuation change

? +12 dB gain shift function

■ Direct mute function

■ Through mode operation

? Input to output direct

■ Output data clocks (LRCO, BCKO)

? External input (slave mode)

? Output system clock generated internally (master mode)

■ CMOS-level input/outputs

■ 5 V (standard) single supply

■ 44-pin QFP

■ Molybdenum-gate CMOS process

APPLICATIONS

■ Digital audio equipment, sample rate conversion (audiovisual amplifiers, CD-R, DAT, MD and 8 mm VTRs)

■ Commercial recording/editing equipment, sample rate conversion

■ Input data jitter elimination