ADAT Optical Audio
Data Generator and Encoder
V1401
1
1. Overview
The V1401 encodes four stereo pairs of digital audio (8 channels, both left and right justied 16, 18, 20, 22 and 24–bit
data formats are supported) and four IO data bits, producing a single data stream suitable for transmission according
to the industry-standard ADAT Optical protocol. It is applied in digital mixing boards, signal processors and sound
reinforcement products, etc. V1401 features are:
• Compatible with ADAT Type I (16–bit) and II (20–bit) formats
• 4 stereo pairs as inputs using standard DAC formats
• Both left and right justied 16, 18, 20, 22 and 24–bit data formats are supported
• 4 IO data inputs to transmit time–code, MIDI data, etc.
• Internal PLL generates all required clocks with a word clock input
• Package: SOP20
2. Block Diagram and Pin Description
2 .1 Block Diagram
V1401
2.2 Block Description
The V1401 Optical Audio Data Generator interface encodes four stereo pairs of digital audio (8 channels) and four IO
data bits, produces a single data stream in the ADAT Optical format. This data stream can be transmitted on the optical
transmitters to the corresponding optical receiver interface.
The internal PLL locks to the rising edge of WDCLK and realizes 256 multiple of frequency. Then the sample clocks
of input data and control signals needed are derived from the output of PLL by the timing control circuitry. These
necessary high frequency clocks and timing signals are used to control the sample and latch circuitry and parallel to
serial circuitry. Four stereo pairs of digital audio (8 channels) and four IO data bits are encoded to a serial data stream
with all data information through these circuits. No Return Zero Inverse (NRZI) encoding of this data stream is realized
through output encode circuitry. Finally, the device outputs a data stream in the ADAT Optical format which is suitable
for far distance optical transmission.
The specic input format of the digital audio data to be used is selected by the format pins CODE3 to CODE0, both left
and right justied 16, 18, 20, 22 and 24–bit data formats are supported. The internal timing control circuitry will provide
corresponding sample clocks and control signals to sample and latch circuitry, thus encoding of digital audio with
different data formats is realized.
2.2.1 Input data formats selection
Both left and right justied 16, 18, 20, 22 and 24–bit data formats are supported in V1401. These formats allow it to
match with different devices, and get a exible application in systems compatible with ADAT protocol. Besides, the
device can operate in parallel with many standard DACs.
The specic input format (for IN1/2~IN7/8) to be used is selected by the format pins CODE3 to CODE0. These data input
formats are outlined in following table.
