Description
The Si4720/21 is the first single chip FM radio transceiver. The proven and patented digital architecture of the Si4720/21 combines the functionality of the Si470x FM radio receiver with the Si471x FM transmitter, offering full FM receive and transmit capabilities in a single, ultra-small 3x3x0.55 mm QFN package. The device leverages Silicon Labs highly successful and proven FM technology, and offers unmatched integration and performance allowing FM receive and transmit to be added to any portable device by using a single chip. As with the Si470x and Si471x products, the Si4720/21 offers industry leading size, performance, low power consumption, and ease of use.

Features
- Integrated FM antenna support
- Excellent real-world performance
- Only two external components required
- Worldwide FM band support (76 to 108 MHz)
- RDS/RBDS processor (Si4721)
- Frequency synthesizer with integrated VCO
- Adjustable seek parameters
- Adjustable mono/stereo blend
- Adjustable soft mute
- Programmable transmit output voltage control
- Audio dynamic range control
- Advanced modulation control
- Analog/digital audio interface
- Programmable reference clock input
- Programmable pre/de-emphasis (50/75 µs)
- 2-wire and 3-wire control interface
- Integrated LDO regulator
- 2.7 to 5.5 V supply voltage
- 3x3x0.55 mm 20-pin Pb-free QFN package

Applications
- Cellular handsets/hands free
- MP3 players
- Portable media players
- GPS/navigation devices
- Satellite digital audio radios
- Personal computers