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Asahi Kasei Microsystems |
ASAHI KASEI
[AK2345]
AK2345
FRS CTCSS Encoder/Decoder
Features
1. CTCSS (Continuous Tone Controlled Squelch System) Encoder/Decoder.
2. Programmable for up to 50 CTCSS frequencies.
3. Integrated CTCSS signal elimination filter.
4. Built-in Adder TX CTCSS/CDCSS and voice signal.
5. Built-in high speed CTCSS Decoder.
6. Conform to CDCSS. (Continuous Digital Controlled Squelch System)
7. Integrated voice signal circuits such as a limiter, splatter filter, etc.
8. Built-in (3.6864 MHz or 4.194304 MHz) oscillator circuit with crystal oscillator.
9. Control register controlled via serial interface.
10. CMOS Process low voltage operation. (1.8V…5.5V)
11. Compact plastic package is used. (24 pin VSOP)
(Page 25)
Description
The AK2345 is an IC which supports CTCSS (Continuous Tone Controlled Squelch System),
compatible with the TIA/EIA-603 standard.
A single CTCSS may be selected from among 50 different frequencies within a range of from
67 to 254.1 Hz. By sending that CTCSS simultaneously with the voice signal during
transmission, and by setting the audio circuit so that it operates only when a CTCSS of that
frequency is detected, it is possible to have multiple communications on the same radio
frequency.
TX has a built-in Adder CTCSS and voice signal, and RX has a built-in high-speed CTCSS
Decoder respectively.
Voice signal filters, a limiter, op-amp, and other circuits are integrated, making it possible to
configure a radio base band unit, especially FRS from a single chip.
■ Pin assignment
TXIN1
TXIN2
TXINO
MOD
MODIN
SPOUT
RXOUT
VDD
XIN
XOUT
STB
SDATA/DCS
1
2
3
4
5
6
7
8
9
10
11
12
24 RXTONE
23 RXIN
22 RXINO
21 AGNDIN
20 AGND
19 LIMLV
18 LIMBS
17 DREF
16 TXTONE
15 VSS
14 DETOUT
13 SCLK
C0041-E-03
-1-
2006/09
ASAHI KASEI
Contents
[AK2345]
Section
Feature………...…………………………………………
Description…………….…………………………………
Block Diagram……….…………………………………..
Circuit Configuration………….…………………………
Pin/Function……………………………………………..
Absolute Maximum Ratings……...…………………….
Recommended Operating Conditions……..………….
Digital Characteristics…...………………………………
Analog Characteristics….……………………………….
Level Diagram……….……………….…………………..
Serial Interface Configuration…………………………..
Operating Explanation…………………………………..
Examples of External Application Circuit……………..
Package…………………………………………….…….
Page
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C0041-E-03
-2-
2006/09
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