Output Circuits - Orban OPTIMOD 6300 Operating Manual

OPTIMOD 6300 DIGITAL
2. Stereo Analog-to-Digital (A/D) Converter
Located on input/output/DSP board
The A/D converter, IC107, is a stereo 24-bit sigma-delta converter. (This is a sur-
face-mount part and is not field-replaceable,)
The A/D oversamples the audio, applies noise shaping, and emits a bitstream at
48 kHz sample rate.
3. Digital Input Receiver and Sample Rate Converter (SRC)
Located on input/output/DSP board
The receiver IC300 accepts digital audio signals using the AES3 interface format
(AES3-1992). It applies its output to sample rate converter IC302. This accepts and
sample-rate converts any of the "standard" 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz,
and 96 kHz rates in addition to any digital audio sample rate within the range of
32 kHz and 96 kHz. The SRC converts the input sample rate to 48 kHz for process-
ing by the DSP.
Receiver IC301 accepts sync signals in either AES11 or wordclock formats and
generate a reference sample rate for the 6300's output sample rate converters.
Relay IC304 determines if the 6300's sync input will accept AES11 or wordclock.
These chips are surface-mounted and not field-replaceable.

Output Circuits

This circuitry interfaces the DSP to the analog and digital audio outputs. The digital
audio from the DSP is transmitted to the digital-to-analog converter (D/A) and out-
put sample rate converter (SRC). The digital-to-analog (D/A) converter converts the
digital audio words generated by the DSP to analog audio. The analog output
stages scale and buffer the D/A output signal to drive the analog output XLR con-
nectors with a low impedance balanced output. The digital output transmitter ac-
cepts the digital audio words from the output sample rate converter (SRC) and
transmits them as AES3-format digital audio signals on the digital output connector.
1. Stereo Digital-to-Analog (D/A) Converter
Located on input/output/DSP board
The D/A, IC211, is a stereo, 24-bit delta-sigma converter. It receives the serial left
and right audio data samples from the DSP at 48 kHz sample rate and converts
them into audio signals requiring further, relatively undemanding analog filter-
ing. IC211 is surface-mounted and is not field-replaceable.
2. Analog Output Stages
Located on input/output/DSP board
The left and right analog signals emerging from IC211 are each filtered, ampli-
fied, and applied to a floating-balanced integrated line driver, which has a 50
output impedance. The line driver outputs are applied to the RF-filtered left and
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TECHNICAL DATA
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