DRS WJ-8611, Инструкция по установке, эксплуатации и обслуживанию

Страница: 138 / 301

WJ-8611 DIGITAL VHF/UHF RECEIVER
5-18 CIRCUIT DESCRIPTIONS
the 10 MHz clock (CLK A and CLK B); the I/Q data (DATA A and
DATA B); the data strobe (STB A and STB B); and an I/Q qualifier (I/Q A
and I/Q B). Their differential configuration is designed to interface with
MC3450 or MC3452 line receivers. The 10 MHz clock rate is constant for
all selected IF bandwidths. The strobe frequency and the I and Q word
rate varies depending on the active IF bandwidth.
Table 5-6 , lists the I and
Q word transfer rate and the strobe frequency for the various IF bandwidth
selections. The only exception to the listed data transfer rates occurs when
the ISB detection mode is selected. The ISB mode always uses a 6.4 kHz
bandwidth, its I and Q word transfer rate is 15.125 kHz, and its strobe rate
is 30.25 kHz.
Table 5-6. I and Q Data Transfer Rates
IF Bandwidth
I and Q Word
Transfer Rate Strobe Rate
200 kHz 60 kHz
150 kHz 50 kHz
100 kHz 35 kHz
250 kHz 500 kHz
30 kHz
20 kHz
15 kHz
10 kHz
62.5 kHz 125 kHz
8 kHz
6.4 kHz*
5.0 kHz
3.2 kHz
31.25 kHz 62.5 kHz
1.0 kHz
.5 kHz
.2 kHz
3.90265 kHz 7.8053 kHz
*If ISB detection mode is selected, the I and Q data transfer rate is 15.125 kHz and
the strobe rate is 30.25 kHz.
The Analog Reconstruction and Output section receives audio/video data
from the DSP circuitry, and converts the digital data to analog output
signals. The Flexible Logic interface provides two output channels, each
containing a serial data signal, a D/A converter clock, and a
synchronization signal for synchronization of the data frames. The first
output channel consists of the VD DAC DATA, the VD DAC CLOCK,
and the VD DAC SYNC1 signals. The second output channel consists of
the ISB DAC DATA, the ISB DAC CLOCK, and the ISB DAC SYNC1
signals. In all detection modes, except for ISB, only the VD DAC DATA
is used. After conversion to an analog signal, the audio is split and is
available at both the LINE A and LINE B audio outputs. The Left and
Right Phone audio outputs also contain the same audio signal. When in
the ISB detection mode, each sideband uses a separate channel. The VD
DAC DATA signal carries the upper sideband audio, and the ISB DAC
Courtesy of http://BlackRadios.terryo.org