DATA BULLETIN
MX165C
Low Voltage
CTCSS Encoder/Decoder
with TX/RX Filters
Features
• Meets TIA/EIA-603 Standards
• 47 CTCSS Tones + Notone
• TX/RX Speech Filters
• Improved Sinad
• Serial or Parallel Programming
• Easy µP Interface
• Scanning on any Channel
• Standard 1MHz Xtal
(See MX465 for 4MHz)
• Low Voltage 3.3V to 5.0V
Applications
• Mobile Radio Channel Sharing
• Scan Trunking
• Wireless Intercom Traffic Control
• Hookswitch Supervision
• Repeater Control
TONE IN
TONE IN
FILTER
+
-
f TONE CLKS
CLKS
TONE DECODE
FILTER
REFERENCE
VOLTAGE
-
+
LOAD/LATCH
D5/SERIAL ENABLE 1
D4/SERIAL ENABLE 2
D3/SERIAL DATA IN
D2/SERIAL CLOCK
D1
D0
RX/TX
PTL
XTAL/CLK
XTAL
CLKS/XTAL
DIGITAL
INTERFACE
AND
CLOCK
GENERATION
CLKS/XTAL
A0-A5
D0-D10
TONE DETECT RX TONE DETECT
LOGIC
TONE OUT FILTER
TX TONE OUT
TONE
ROM
48 x 10
VDD
VSS
VBIAS
TX AUDIO IN
RX AUDIO IN
DECODE COMPARATOR REF.
DECODE COMPARATOR IN
CLK
300Hz
AUDIO FILTER
+
-
TX AUDIO OUT
RX AUDIO OUT
RX TONE DECODE
The MX165C CTCSS Encoder/Decoder is a low voltage, CMOS device that meets TIA/EIA-603 Standards. The MX165C
will encode and decode the tones 159.8Hz, 183.5Hz, 189.9Hz, 196.6Hz, 199.5Hz, 206.5Hz, 229.1Hz, and 254.1Hz in
addition to the 39 standard CTCSS tones, for a total of 47 CTCSS tones + Notone. With the incorporation of the on-chip
TX and RX speech filter, the MX165C enhances voice/tone multiplexing by attenuating TX and RX speech 36dB at
frequencies below 250Hz while passing signals > 300Hz with only 1dB of ripple. This not only minimizes CTCSS talk-off
in the TX mode but also improves Hum and Noise performance in the RX mode.
Available in the following package styles: 24-pin TSSOP (MX165CTN), 24-pin SOIC (MX165CDW), 24-pin PLCC
(MX165CLH), and 24-pin PDIP (MX165CP), the MX165C requires a single 3.3V to 5.0V supply and a 1MHz clock or
crystal.
© 1997 MX•COM Inc.
www.mxcom.com Tele: 800 638-5577 910 744-5050 Fax: 910 744-5054
Doc. # 20480102.008
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.