RDA1846S
四年级读书小报S INGLE C HIP T RANSCEIVER F OR W ALKIE T ALKIE Rev.0.1–Aug.2011新鲜反义词
1. General Description
The RDA1846S is a highly integrated single-chip transceiver for Walkie Talkie applications. It totally rea
lizes 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 RDA1846S has a powerful digital signal processor, which makes it have optimum voice quality, flexible function options, and robust performance under varying reception conditions. The RDA1846S 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 us 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 nsitive RF circuits on PCB.1.1 Features
● CMOS single-chip fully-integrated transceiver ● Fully integrated frequency synthesizer and VCO ● Support worldwide frequency band
RDA1846S :134MHz ~ 174MHz
200MHz~ 260MHz 400MHz ~ 520MHz
● 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 pha 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/I 2C rial control bus interface ● On chip 8 dBm P A
● 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
handts ● Family radio rvices ● Walkie T
alkies
A F O U T
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M I C _I N
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G P I O 0
G P I O 1
G P I O 2
G P I O 3
G P I O 4
G P I O 5
G P I O 6G P I O 7
Figure 1.1 RDA1846S Top View
2. Table of Contents
1.General Description (1)
1.1Features (1)
1.2Applications (1)
2.Table of Contents (2)
3.Functional Description (3)
店面橱窗设计3.1RF input and output (3)
3.2Voice input and output (4)
3.3Synthesizer (4)
3.4XTAL Clock (4)
3.5DSP functions (4)
3.6Integrated LDO (4)
3.7Serial Control Interface (4)闽南话骂人
4.Electrical Characteristics (5)
5.Receiver/Transmitter Characteristics (6)
6.Control Interface Characteristics (7)
证件照拍摄
7.Pins Description (8)
8.Application Diagram (11)
9.Package Outline (12)
10.Solder Mounting Condition (13)
11.Change List (16)
12.Contact Information (16)
3. Functional Description
…
Figure 3.1 RDA1846S Block Diagram
The RDA1846S transceiver features very low solution cost and reduced complexity. As shown in Fig.3.1, to totally complete the translation from RF carrier to voice in the RX path and from voice to RF carrier in the TX path, the chip integrates nearly all the functional blocks including RF and ba band analog blocks and digital signal processor. It requires only one micro controller and a few external components to realize a walkie-talkie.
A powerful integrated DSP accomplishes both the demodulation and modulation of the FM signal. Besides, standard walkie-talkie features such as CTS, CDS, VOX and SQ etc. are provided through the 8 GPIOs of the chip. Especially, by virtue of the state-of-the-art CMOS technology advanced algorithms such as AFC, AGC, RSSI and SNR calculations are realized in the DSP, which guarantees the high receiving and transmitting quality while still consumes a low power. Flexible RX/TX/SLEEP auto switching function from the DSP further reduces the average power consumptions.
LDOs are also integrated in the chip which further reduces the BOMs.
All interface pins of the chip will be shortly explained below. For details, refer to the ‘RDA 1846 programming guide’.
3.1 RF input and output选择题答题卡
The chip can receive and transmit RF signals from 400 to 500MHz and from 134 to 174MHz which cover most of the walkie-talkie frequency bands around the world and the weather broadcast band. For the RF input, a direct-in connection from the antenna to the LNA input pin through a switch is suggested which means no input impedance matching is needed for the receive band. For the RF out, a pa diver can deliver no more than 8 dBm power to PA. PA bias voltage from 1.5V~2.8V for the power amplifier can be supplied from the PABIAS pin.
3.2 Voice input and output
In the RX path, the voice signal after demodulation is nt to the internal DAC which can directly drive a 32Ω resistance loading through AC coupling. In the TX path, microphone signal can be nt into the chip through AC coupling capacitors.
3.3 Synthesizer
The frequency synthesizer generates the local oscillator signal. All building blocks are fully integrated without any external components. LO frequency can be programmed through the rial interface by t
he MCU. (How to lect frequency band and program LO frequency, refer to the programming guide)
3.4 XTAL Clock
The RDA1846S supports XT AL clocks such as 12.8 MHz, 13 MHz, 25.6 MHz and 26 MHz. The internal XTAL oscillator can also be bypasd thus TCXO clock with appropriate amplitude can be nt into the chip directly. (How to configure the internal XTAL oscillator, refer to the programming guide)
3.5 DSP functions
The DSP accomplishes the demodulation and modulation of the FM signal. Standard walkie-talkie features such as CTS, CDS, VOX and SQ etc. are provided through the 8 GPIOs. (How to configure the
GPIOs, refer to the programming guide)
3.6 Integrated LDO
LDOs are integrated on chip which eliminates using one LDO chip on the PCB. Supply voltage for th
e chip is suggested to be within 3.3V~4.8V. A common share of the supply voltage for RDA1846S and other chips or on board circuits are not appropriate and thus not recommended.
3.7 Serial Control Interface
A 3-wire/4-wire/I2C rial interface is provided for host IC to read and write RDA1846S control registers. (For details of the rial control interface, refer to the programming guide).
4. Electrical Characteristics
Table 4-1 DC Electrical Specification (Recommended Operation Conditions): SYMBOL DESCRIPTION MIN TYP MAX UNIT
AVDD Supply Voltage from battery or LDO 3.3 3.3 4.8 V
T amb Ambient Temperature -25 27 +85 ℃
V L CMOS Low Level Input/output Voltage 0 0.3 V
V H CMOS High Level Input/output Voltage 2.7 3 V单元工程
V TH CMOS
Voltage 1.5 V Threshold
Table 4-2 DC Electrical Specification (Absolute Maximum Ratings):
SYMBOL DESCRIPTION MIN TYP MAX UNIT
T amb Ambient Temperature -40 +90 °C
I IN Input Current-10 +10 mA
V IN Input Voltage -0.3 3.3 V
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V lna LNA Input Level +10 dBm
Table 4-3 Power consumption specification
(AVDD = 3.3 V, T A = -25 to 85℃, unless otherwi specified)
STATE DESCRIPTION Condition TYP UNIT
I
Continue Receive RXON=1,PDN=1 58 mA
I Tx Continue Transmit TXON=1,PDN=1 50 mA
I sleep Deep sleep PDN=0 60 A
