CML Semiconductor Products
CTCSS Signalling Processor FX818
1.0 Features
• Fast CTCSS Detection
• Non Predictive Tone Detection
• Low Power 3.3V/5V Operation
• Variable Gain Audio Filter
D/818/4 July 1997
Provisional Issue
• Programmable Tone Decoder
• Programmable Modulator Drivers
• Programmable Tone Encoders
• Compact (SSOP and SOIC)
Packaging
1.1 Brief Description
The FX818 is an innovative CTCSS Codec designed for the latest generation of Land Mobile Radio equipment.
The FX818 is full duplex and has many advanced features which assist the operation of modern CTCSS based
systems. The FX818 is electrically, physically and software compatible with the FX828. It permits
manufacturers to add new features to their equipment with minimal design changes.
The FX818 incorporates a programmable tone decoder which can be set to respond to between 1 and 15
CTCSS tones with minimum software intervention. In addition, a 'Fast' CTCSS detector can respond to a
single programmed tone in 60ms, or can be used to provide an output if any CTCSS tone is present at the
detector input. A high resolution tone encoder performs accurate generation of any CTCSS tone in current use.
High pass and low pass filters are included to provide filtering for CTCSS and Voice band signals. On chip
audio summation amplifier and digital adjustable modulator drivers ensure easy integration into equipment.
The FX818 along with the FX828 is offered in a choice of small SSOP and SOIC 24-pin packages. It may be
used with 3.0 to 5.5 volt supply.
© 1997 Consumer Microcircuits Limited