MX803AJ Ver la hoja de datos (PDF) - MX-COM Inc
Número de pieza
componentes Descripción
Fabricante
MX803AJ Datasheet PDF : 26 Pages
| |||
Audio Signaling Processor
MX803A
TONE 2 OUT
17
16
TONE 1 OUT
7
MX803A PRELIMINARY INFORMATION
AUDIO SWITCH IN
10
FROM MX806A
MAIN PROCESS OUT
TO MX806A
SUM IN
11 AUDIO SWITCH OUT
SUM IN
BIAS
19
CAL
CUES
+
_
SUMMING
AMPLIFIER
18 CAL/CUES OUT
TO MX806A
CALIBRATION IN
21
SWITCHED SUM OUT
20 SUM OUT
Figure 3: Example of Signal Switching in a DBS800 microcircuit
4. General Description
4.1 DESCRIPTION
The MX803A is an audio signaling processor that provides inband tone signaling capabilities for LMR and other Radio
systems. A low-power CMOS device, the MX803A is a member of the DBS800 (Digitally integrated Baseband Sub-
system) IC family (See section 4.2). Supported Signaling systems include SelCall (CCIR, EEA, ZVEI I, II, and III) 2-Tone
SelCall and DTMF encode. The use of a non-predictive decoder and a versatile encoder, allows the MX803A to operate
in any standard or non-standard tone system.
The MX803A is a full-duplex device for use with Single Tone or Selective Call systems. The MX803A consists of a tone
decoder with a programmable NOTONE timer, two individual tone encoders and a programmable TX period timer, and an
on-chip summing amplifier. Under the control of a µC, the MX803A will simultaneously encode and transmit 1 or 2 audio
tones in the 208-3000Hz range, as well as detect, decode, and indicate the frequency of any non-predicted input tone in
the frequency range of 313 to 6000Hz.
A general purpose logic input, interfacing directly with the Status Register, is provided. This may be used as an auxiliary
method of routing digital information to the µC via C-BUS. Output frequencies are produced from data loaded to the
MX803A. A programmable, general purpose, on-chip timer sets the tone transmit periods. A Dual-Tone Multi-Frequency
(DTMF) output is obtained by combining the 2 independent output frequencies in the integral summing amplifier. This
process can also be used for level correction.
Tones produced by the MX803A can be used in the system as modulation calibration inputs and as “CUE” audio
indications to the operator. Received tones are measured and their frequency indicated to the µC in the form of a
received data word. A poor quality or incoherent tone will indicate Notone.
4.2 DBS800 Systems
The Digitally-Integrated Baseband Subsystem (DBS800) is a family of low power ICs which provide a comprehensive
range of audio processing and signaling functions for use within LMR and other Radio Systems. Each DBS800 IC may
be used as part of a complete audio system, or each IC may operate as a stand alone. The system and ICs are
partitioned in such a way that radio designers can easily select the device or devices appropriate to their needs.
The DBS800 family consists of the following ICs:
4.2.1 MX802 DVSR Codec
This is a full-duplex CVSD speech encoder/decoder with the ability to store and retrieve data within attached DRAM
(Dynamic Random Access Memory) using an on-chip DRAM controller. The MX802 also provides on-chip input and
output audio filtering.
4.2.2 MX803A Audio Signaling Processor
This provides an inband tone signaling ability to LMR and other Radio Systems.
© 1996 MX•COM, INC.
Tele: 800 638 5577 910 744 5050 Fax: 910 744 5054
Doc. # 20480122.003
Share Link: 