AK2347A Datasheet, PDF (1/34 Pages) Asahi Kasei Microsystems – Two-way Radio Audio & Sub-Audio Processor

[AK2347A]
AK2347A
Two-way Radio Audio & Sub-Audio Processor
Features
• Audio processing
• TX and RX amplifier
• Pre/De-emphasis circuit
• Compressor and Expander with no external components
• Scrambler and De-scrambler in frequency inversion type (3.388kHz or 3.290kHz)
• Limiter with level adjuster
• Splatter filter for wide and narrow band
• Digital controlled amplifier for microphone, modulator and demodulator sensitivity
• Sub-Audio filter with level adjuster for CTCSS and DCS
• Low power supply operation: 2.7 to 3,3V
• Wide range operating for temperature: -40 to 85 °C
• Oscillator circuit for 3.6864MHz and 3.579545MHz crystal
• Serial control interface operation
• Compact plastic packaging, 24-pin QFNJ (4.0x4.0x0.75mm 0.5mm pitch)
Description
AK2347A includes audio filter, limiter, splatter filter, compandor, scrambler, which is highly integrated
two-way radio baseband functions for FRS and LMR.
Audio high-pass filter shows a high attenuation in magnitude response characteristics under 250Hz
that supports to eliminate a subaudio tone clearly.
TX limiter for deviation control has a limiting level adjuster by applying a DC voltage via external
components. Splatter filter has the magnitude response for narrowband(fc=2.55kHz) and
wideband(3.0kHz) to meet various regulatory agencies in the world wide.
Compandor is no adjustment type because it includes all parametric components inside the chip.
Scrambler circuit is composed of frequency inversion circuit by double balanced mixer that has
3.388kHz and 3.290kHz carrier clock.
Sub-Audio filter with level adjuster is available for pre- or post-filter for CTCSS and DCS.
There are four signal level adjusters for microphone, modulator and demodulator sensitivity by digital
controlled amplifier (volume).
• Pin Assignment (Top view)
MS0946-E-00
F I LT E R O
RXINO
RXIN
AGNDIN
AGND
TXINO
18 17 16 15 14 13
19
12 XOUT
20
11 XIN
21
10 TEST
22
9 CSN
23
8 SCLK
24
7 SDATA
123456
-1-
2008/03