Economy audio CODEC for MiniDisc (MD) home stereo and portable applications
Filter Stream Digital-to-Analog Converter (FSDAC)
The FSDAC is a semi-digital reconstruction filter that converts the 1-bit data stream of the noise shaper to an analog output voltage. The filter coefficients are implemented as current sources and are summed at virtual ground of the output operational amplifier. In this way very high signal-to-noise performance and low clock jitter sensitivity is achieved. A post filter is not needed due to the inherent filter function of the DAC. On-board amplifiers convert the FSDAC output current to an output voltage signal capable of driving a line output.
Multiple format input/output interface
The UDA1341TS supports the following data formats:
I2S-bus with word length up to 20 bits
MSB-justified serial format with word length up to 20 bits
LSB-justified serial format with word length of
16, 18 or 20 bits
MSB data output with LSB 16, 18 or 20 bits input.
Left and right data-channel words are time multiplexed. The formats are illustrated in Fig.4.
The UDA1341TS allows for double speed data monitoring purposes. In this case the sound features bass boost, treble and de-emphasis cannot be used. However, volume control and soft-mute can still be controlled. The double speed monitoring option can be set via the L3-interface.
The bit clock frequency must be 64 times word select frequency or less, so fBCK ≤ 64 × fWS .
2002 May 16