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RDA1846
SINGLE CHIP TRANSCEIVER FOR WALKIE TALKIE Rev.1.2–Dec.2009
1. General Description
The RDA1846 is a highly integrated single-chip
transceiver for Walkie Talkie applications. It totally
realizes the translation from RF carrier to voice in
the RX path and from voice to RF carrier in the TX
path, requiring only one micro controller.
The RDA1846 has a powerful digital signal
processor, which makes it have optimum voice
quality, flexible function options, and robust
performance under varying reception conditions.
The RDA1846 can be tuned to the worldwide
frequency band for Walkie Talkie from 400MHz to
500MHz and especially from 134MHz to 174MHz
which meets the frequency band of weather
broadcast.
The transceiver uses the CMOS process with a
package size of 5X5mm. By virtue of its high
integration, it requires the least external
components and eliminates the complicated
design of sensitive RF circuits on PCB.
1.1 Features
Figure 1.1 RDA1846 Top View
CMOS single-chip fully-integrated transceiver
Fully integrated frequency synthesizer and VCO
Support worldwide frequency band
134MHz ~ 174MHz
400MHz ~ 500MHz
12.5KHz, 25KHz channels
Support multiple XTAL clocks
12.8/25.6Mhz
13/26Mhz
Digital auto frequency control (AFC)
Digital auto gain control (AGC)
Selectable pre/de-emphasis
Received signal strength indicator (RSSI)
VOX and SQ
Build-in CTCSS/CDCSS generator and judgment
CTCSS with 120/180 /240 degree phase shift
23/24 bit programmable DCS code
DTMF and programmable in-band dual tone
Programmable in-band single tone transmitter
Auto RX/TX/SLEEP state switching
8 GPIOs
3-wire/4-wire/I2C serial control bus interface
On chip 8 dBm PA
Analog and digital volume control
Directly support 32Ω resistance loading
3.3 to 4.8 V supply voltage with Integrated LDO
5X5 mm 32 pin QFN package
1.2 Applications
Cellular handsets
Family radio services
Walkie Talkies
Copyright © RDA Microelectronics Inc. 2009. 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.
Free Datasheet http://www.Datasheet4U.com
RDA Microelectronics, Inc.
4. Electrical Characteristics
RDA1846 SPEC V1.2e
Table 4-1 DC Electrical Specification (Recommended Operation Conditions):
SYMBOL
DESCRIPTION
MIN TYP MAX
AVDD
Supply Voltage from battery or LDO
3.3 3.3 4.8
Tamb
VL
VH
VTH
Ambient Temperature
-25 27 +85
CMOS Low Level Input/output Voltage
0
0.3
CMOS High Level Input/output Voltage
2.7
3
CMOS Threshold Voltage
1.5
UNIT
V
℃
V
V
V
Table 4-2 DC Electrical Specification (Absolute Maximum Ratings):
SYMBOL
Tamb
IIN
VIN
Vlna
DESCRIPTION
Ambient Temperature
Input Current
Input Voltage
LNA Input Level
MIN TYP
-40
-10
-0.3
MAX
+90
+10
3.3
+10
UNIT
°C
mA
V
dBm
Table 4-3 Power consumption specification
(AVDD = 3.3 V, TA = -25 to 85℃, unless otherwise specified)
STATE
IRx
ITx
Isleep
DESCRIPTION
Continue Receive
Continue Transmit
Deep sleep
Condition
RXON=1,PDN=1
TXON=1,PDN=1
PDN=0
TYP UNIT
55 mA
50 mA
40 A
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.
Page 5 of 16
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RDA Microelectronics, Inc.
8. Application Diagram
RDA1846 SPEC V1.2e
Figure 8.1 RDA1846 Application Diagram
Notes:
1 U1: RDA1846 Chip;
2 AVDD: Power Supply for RDA1846 (3.3~4.8V);
3 AVDD_PA: Power Supply for RF PA, its voltage depends on the actual PA design;
4 C0~C11: AVDD decouple capacitance (1nF and 100nF in pairs), as close to AVDD pin as possible;
5 CA1~CA2: Audio AC couple capacitance (~47uF);
6 Cc: Compensation capacitance connected between pin Cc and GND (~47uF);
7 Crf: RF AC couple capacitance (~150pF);
8 CX1~CX2: XTAL oscillator load capacitance. Its value depends on the chosen XTAL (if using external TCXO, clk
should be sent into pin XTAL1 with Vpp about 1.5V, and pin XTAL2 should be connected to GND);
9 R0~R1(optional): resistors for serial interface wire SDIO and SCLK (~10kΩ);
10 Pins NC(10,14,17,19,20) should be floating;
11 External vox detection circuit is optional;
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.
Page 11 of 16
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