User's Manual

Model 1150A DVOR
Rev. - November, 2008
This document contains proprietary information and such information may not be disclosed
to others for any purposes without written permission from SELEX Sistemi Integrati Inc.
2-17
Figure 2-8 Audio Generator CCA Block Diagram
2.3.2.3
Audio Generator CCA Detailed Circuit Theory
Refer to Figure 11-13. All signals and power supplies of the Audio Generator CCA enter and exit through right-
angle DIN connectors P1 and P2; which connect to the Control Backplane CCA.
The +5V from connector P1-C1is filtered by capacitors C48 and C51 as well as inductor L4 to create +5VA for
powering analog circuitry. +5V is also regulated by U17 to create +3.3V for powering digital circuitry. The +12V
from connector P1-A31 is filtered by capacitors C49, C53, and C55 as well as inductor L2 to make +12ANA for
powering analog circuitry. The -12V from connector P1-C32 is filtered by capacitors C50, C52, and C54 as well as
inductor L3 to make -12ANA for powering analog circuitry.
The +12ANA is regulated by reference U15 and adjusted by potentiometer R185 to create +VREF. The +VREF sets
the level on DACs U31-4, U33-1, and U33-2. Finally the -12ANA is regulated by U16 to make -5VA for powering
analog circuitry. Diode CR8 helps prevent latch-up upon power-up.
DSP U6 communicates to the RMS CCA through UART U12 and TTL-RS232 converter U14 as signals AGEN_TX
(U14-10) and AGEN_RX (U14-11) to connector P1-A3 and P1-A4. Factory-only RS232 communication ports
DEBUG and SPARE are also available on headers JP1 and JP2.