Document
ASAHI KASEI
[AK2346A]
AK2346A
Two-way Radio Audio Processor
1. 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 with 16 different carrier clocks • Limiter with level adjuster • Splatter filter for wide and narrow band • Digital controlled amplifier for microphone, modulator and demodulator sensitivity • 1200/2400bit/s MSK Modem with frame detection • Wide range operation voltage: 2.6V to 5.5V, temperature: -40 to 85 °C • Oscillator circuit for 14.7456MHz crystal • Serial control interface operation • Compact plastic packaging, 24-pin QFNJ (4.0 x 4.0 x 0.75mm 0.5mm pitch)
2. Description
AK2346A includes audio filter, limiter, splatter filter, Compandor, scrambler, MSK Modem, 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 less than 250Hz that supports to eliminate a sub-audio tone clearly. TX limiter for deviation control has a limiting level adjuster controlled by a 4-bit signal level adjuster. 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 16 different carrier clocks. MSK Modem for data communication can be chosen either 2400bit/s or 1200bit/s. 2400bit/s data rate provides a high speed data transmission and 1200bit/s supports a low BER (bit error rate) performance that is suitable for under weak electrical field condition application. There are four signal level adjusters for microphone, modulator and demodulator sensitivity by digital controlled amplifier (volume).
MS1289-E-02 -1-
2 012/06
http://www.Datasheet4U.com
ASAHI KASEI
[AK2346A]
3. Contents
1. Features······························································································································· 1 2. Description················································································································· ·········· 1 3. Contents ···················································································································· ·········· 2 4. Block Diagram ··············································································································· ······ 3 5. Circuit Configuration ······································································································· ····· 4 6. Pin/Function················································································································ ········· 5 7. Absolute Maximum Ratings ································································································· 8 8. Recommended Operating Conditions ·················································································· 8 9. Digital DC Characteristics ·································································································· ·· 8 10. Clock Input Characteristics ································································································ 9 11. System Reset ··············································································································· ····· 9 12. Power Consumption········································································································· 10 13. Analog Characteristics ····································································································· 11 14. Level Diagram·············································································································· ···· 16 15. Serial Interface Configuration ·························································································· 17 16. Digital AC Timing ·········································································································· ··· 27 17. MSK Modem Description ································································································· 30 18. Recommended External Application Circuits ··································································· 33 19. Packaging ·················································································································· ······ 36 20. Important Notice ··········································································································· ··· 37
MS1289-E-02 -2-
2 012/06
ASAHI KASEI
[AK2346A]
4. Block Diagram
EXTINO
EXTIN1
16 TXINO 20 19 TXIN + TXA1 Adder 1 VR1 (HPF) Compressor TC
PreEmphasis
17 + TXA2
EM
EXTIN2 21
DAC
TXSW 2,1,0 LIMSW
-18 to +4.5/1.5dB
fc = 300Hz TX/RX _HPF TXRX PCONT HPFSW TXRX PCONT
Scrambler/ Descrambler
A.