FX365CDW View Datasheet(PDF) - CML Microsystems Plc
Part Name
Description
Manufacturer
FX365CDW Datasheet PDF : 9 Pages
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CML Semiconductor Products
PRODUCT INFORMATION
FX365C Low-Voltage CTCSS Encoder/
Decoder
Publication D/365C/3 October 1995
Features
Low-Voltage (3-Volt) Supply
39 Programmable Sub-Audio
Tones + NOTONE
Meets MPT1306 and EIA - 220 B
High Voiceband/CTCSS Isolation
Separate Sub-Audio and Rx/Tx
Audio Paths and Filtering
Applications
Mobile Radio Systems
Community Base Stations
“Sports Radio” (Japan)
Sub-Audio Signalling and Selec-
tive Calling
Status and Alarm Systems
Amateur Radio
Tx
Tx AUDIO
INPUT
VOICE-AUDIO PATH
Tx
300Hz
Tx AUDIO
OUTPUT
Rx AUDIO
INPUT
XTAL/CLOCK
XTAL
(Rx)
SUB-AUDIO
TONE INPUT
LOAD/LATCH
SERIAL ENABLE 1/D5
SERIAL ENABLE 2/D4
SERIAL DATA/D3
SERIAL CLOCK/D2
D1
D0
Rx/Tx
PTL
Rx
XTAL/CLOCK
GENERATOR
SUB-AUDIO PATH
fTONE
8-BIT
SERIAL
SHIFT
REGISTER
8-BIT
LATCH
LOGIC
VDD 2VDD
3
3
(Rx)
CONTROL
Rx AUDIO
OUTPUT
VDD
DIGITAL
PERIOD
DETECTOR
OUTPUT
LATCH
TONE FREQUENCY
BUS
PROGRAM
LOGIC
TONE
GENERATOR
Tx ENABLE
CONTROL
LOGIC
Rx TONE
DETECT
VBIAS
Tx TONE
OUTPUT
VSS
DECODE
COMPARATOR REF.
DECODE
COMPARATOR
INPUT
Fig.1 Functional Block Diagram
+
-
DECODE COMPARATOR
Rx TONE DECODE
OUTPUT
FX365C
Brief Description
The FX365C is a 3-volt, half-duplex predictive
Continuous Tone Controlled Squelch System
(CTCSS) encoder/decoder microcircuit. The FX365C
has integral voice-band filtering for prefiltering of Tx
audio and the rejection of the CTCSS tone in receive.
Under µProcessor control, the FX365C will encode
and decode any one of 39 sub-audio frequencies
(+NOTONE) in the range 67.0Hz to 250.3Hz. Tone
frequencies and all functional commands can be
loaded to the device in either pin-selectable 8-bit
parallel or serial format.
A separate, Rx/Tx voice-audio path is available with
a highpass (sub-audio reject) filter automatically
placed in the relevant Rx or Tx voice line.
The Rx sub-audio (CTCSS) path contains a
(selected tone frequency) bandpass filter and period
detector providing a logic level output (Rx Tone
Detect) to indicate a successful decode operation.
Rx “Press to Listen” (PTL) and Tx “Squelch-Tail
Elimination” functions are available in both command
loading modes. The squelch-tail elimination function
will provide (Tx tone) phase-reversal to minimise the
annoying audio outputs that occur at the receiver on
completion of a transmission.
Tone frequencies and filter accuracies are
maintained by an on-chip 1.0MHz clock oscillator
employing an external crystal or clock pulse input.
The FX365C, which exhibits high audio and sub-
audio performance with low falsing, is available in 24-
pin DIL and small outline SMD packages.
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