Document
Si4712/13-B30
FM RADIO TRANSMITTER WITH RECEIVE POWER SCAN
Features
Integrated receive power measurement Worldwide FM band support (76–108 MHz) Requires only two external components Frequency synthesizer with integrated VCO Digital stereo modulator Programmable pre-emphasis Analog/digital audio interface Audio silence detector Programmable reference clock
RDS/RBDS encoder (Si4713 only) PCB loop and stub antenna support with self-calibrated capacitor tuning Programmable transmit level Audio dynamic range control Advanced modulation control 2.7 to 5.5 V supply voltage Integrated LDO regulator 3 x 3 x 0.55 mm 20-pin QFN
Pb-free and RoHS Compliant Designed for compatibility with cellular operation
Applications
Cellular handsets/hands-free MP3 players Portable media players
Wireless speakers/microphone Satellite digital audio radios Personal computers/notebooks
Description
The Si4712/13-B30 integrates the complete transmit functions for standards-compliant unlicensed FM broadcast stereo transmission. The chip also allows integrated receive power scanning to identify low signal power FM channels. Users must comply with local regulations on radio frequency (RF) transmission.
Functional Block Diagram
Si4712/13
Ordering Information: See page 34.
Pin Assignments Si4712/13-B30 (Top View)
NC GPO1 GPO2/INT GPO3/DCLK LIN
NC 1 20 19 18 17 16
NC 2
15 RIN
RFGND 3 TXO 4
GND PAD
14 DFS 13 DIN
RST 5
12 GND
6 7 8 9 10 11 VDD
SEN SCLK SDIO RCLK
VIO
Tx Ant TXO
L1 120 nH
RFGND
PEAK DETECT
DIGITAL AUDIO
DSP DAC ADC
DAC ADC
DIN DFS
LIN RIN
Patents pending
Note: To ensure proper operation and performance, follow the guidelines in “AN383: Universal Antenna Selection and Layout Guidelines.” Silicon Laboratories will evaluate schematics and layouts for qualified customers.
VDD 2.7–5.5 V
AFC
CONTROL INTERFACE
GPO RDS (Si4713)
LDO
GND C1
22 nF
RCLK VIO RST
SDIO SCLK
SEN GPO3/ DCLK GPO2/
INT GPO1
Rev. 1.1 2/08
Copyright © 2008 by Silicon Laboratories
Si4712/13-B30
Si4712/13-B30
2 Rev. 1.1
TABLE OF CONTENTS
Si4712/13-B30
Section
Page
1. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 2. Test Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.1. Test Circuit Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.2. Test Circuit Bill of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3. Typical Application Schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.1. Analog Audio Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.2. Digital Audio Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.3. Typical Application Schematic Bill of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4. Universal AM/FM RX/FM TX Application Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 4.1. Universal AM/FM RX/FM TX Bill of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 5. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 5.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 5.2. FM Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 5.3. Receive Power Scan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 5.4. Digital Audio Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 5.5. Line Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 5.6. Audio Dynamic Range Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 5.7. Audio Limiter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 5.8. Pre-emphasis and De-emphasis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 5.9. RDS/RBDS Processor (Si4713 Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 5.10. Tuning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 5.11. Reference Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 5.12. Control Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 5.13. GPO Outputs . . . . . . . . .