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RDA |
RDA1845
SINGLE CHIP TRANSCEIVER FOR WALKIE TALKIE Rev.1.0–Feb.2008
1. General Description
The RDA1845 is a single-chip transceiver for
Walkie Talkie with fully integrated synthesizer, IF
selectivity and base-band signal processing. The
transceiver uses the CMOS process, support
digital volume control and require the least
external component. The package size is 6X6mm
and is completely adjustment-free.
The RDA1845 has a powerful low-IF digital audio
processor, this make it have optimum sound
quality with varying reception conditions.
The RDA1845 can be tuned to the worldwide
frequency band for Walkie Talkie.
1.1 Features
z CMOS single-chip fully-integrated transceiver
z Support worldwide frequency band
¾ 300Mhz-500 MHz
¾ 12.5Khz,25Khz channels
z Digital low-IF tuner
¾ Image-reject down-converter
¾ High performance A/D converter
¾ IF selectivity performed internally
z Fully integrated digital frequency synthesizer
¾ fully integrated on-chip RF and IF VCO
¾ fully integrated on-chip loop filter
z Auto DC offset calibration
z Digital auto frequency control (AFC)
z Digital auto gain control (AGC)
z Support multi-reference clocks
¾ 12.8/25.6Mhz
¾ 13/26Mhz
z Selectable pre/de-emphasis
Figure 1. RDA1845 Top View
z Support CTCSS and CDCSS
z Receive signal strength indicator (RSSI)
z Provide programmable VOX and Squelch indicator
z Analog and digital volume control
z Reference clock drift compensation
z 3-wire serial control bus interface
z Directly support 32Ω resistance loading
z Integrated LDO regulator
¾ 2.7 to 3.3 V operation voltage
z 6X6mm 40 pin QFN package
1.2 Applications
z Cellular handsets
z Family radio services
z Walkie Talkies
Copyright © RDA Microelectronics Inc. 2006. All rights are reserved.
The information contained herein is the exclusive property of RDA and shall not be distributed, reproduced, or disclosed in whole or in
part without prior written permission of RDA.
RDA Microelectronics, Inc.
2. Table of Contents
RDA1845 SPEC V1.0e
1. General Description ....................................................................................................................................1
1.1 Features........................................................................................................................................1
1.2 Applications .................................................................................................................................1
2. Table of Contents.........................................................................................................................................2
3. Functional Description................................................................................................................................3
3.1 Synthesizer ...................................................................................................................................3
3.2 Reference Clock...........................................................................................................................3
3.3 Serial Control Interface ..............................................................................................................3
4. Electrical Characteristics ...........................................................................................................................4
5. Transmit/Receiver Characteristics ............................................................................................................5
6. Control Interface Characteristics ..............................................................................................................6
Three-wire Interface Timing ......................................................................................................................6
7. Pins Description...........................................................................................................................................7
8. Application Diagram...................................................................................................................................9
9. Package Physical Dimension ....................................................................................................................10
10. Change List................................................................................................................................................ 11
11. Contact Information ................................................................................................................................. 11
The information contained herein is the exclusive property of RDA and shall not be distributed, reproduced, or disclosed in whole or in
part without prior written permission of RDA.
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