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Programmable Tone Decoder
Programmable Comparator for RSSI
Programmable Modulator Drivers
Programmable Tone Encoders
Full Duplex CTCSS and Selcall
1.1
Brief Description
The FX828 is an innovative CTCSS, DCS and Selcall Codec, designed for the latest generation of Land Mobile
Radio equipment. Designed to complement the FX829, the FX828 has many advanced features which assist
the operation of modern SUBAUDIO and INBAND based signalling systems. The FX828 is electrically,
physically and software compatible with the FX818 and FX829. It permits manufacturers to add new features
to their equipment with minimal design changes.
The FX828 incorporates a programmable tone decoder which can be set to respond to between 1 and 15
CTCSS or Selcall tones with minimum software intervention. In addition, a 'Fast' CTCSS detector can respond
to a single programmed tone in 60 ms, or can be used to provide an output if any CTCSS tone is present at the
detector input. Two high resolution tone encoders perform accurate generation of any CTCSS or Selcall tone
in current use. Full 23 or 24 bit DCS encoding and decoding complements the CTCSS/Selcall line-up. A timer
is included which, for example, may be used for timing Selcall transmissions and a comparator is provided to
assist with carrier or RSSI monitoring. The device can operate full duplex in all operating modes except for
DCS.
The FX828 along with the FX818 and FX829 is offered in a choice of small SSOP, DIL and SOIC 24-pin
packages. It may be used with 3.0 to 5.5 volt supply.
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1997
Consumer Microcircuits Limited