
Nippon Precision Circuits
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