​Si4704/05 FM Radio Receiver ICs

The Si4704/05 enhanced FM receiver family is the most advanced portable solution available today offering digital audio out, worldwide FM band support and highly flexible, mature and proven FM functionality in a simple API.
The Si4705 IC offers digital audio out for FM recording.  The content can also be tagged with RDS information, allowing song name and artist labels to be displayed as is done with MP3 meta data. Using the digital audio out, the Si4705 can also reduce total system power consumption by avoiding unnecessary ADC/DAC conversions between the FM receiver and the host processor.


  • Worldwide FM band support (64~108 MHz)
  • Supports integrated antenna
  • Seek tuning
  • Automatic frequency control (AFC)
  • Automatic gain control (AGC)
  • Adjustable seek parameters
  • Adjustable mono/stereo blend



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Data Sheet (2)

Data Short (1)

User Guides (1)

Si47xx-EVB User Guide
0.83/14/20149789 kB

Application Notes (8)

White Papers (4)

PCN (9)

Development Kits

Design Tools

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Software (2)

0.31/24/200968 kB
Release Notes for the Precision Clock (DSPLLsim) EVB Software
7/23/20149 kB
Product Matrix
Part NumberDescriptionTuning MethodDisplay MethodMono/StereoRDSFMAMSWLWWBTXEN55020Datasheet
Si4704FM Receiver, short antenna capableDigitalDigitalStereoNoYesNoNoNoNoNoYes
Si4705FM Receiver w RDS, short antenna capableDigitalDigitalStereoYesYesNoNoNoNoNoYes


    • Digital Low-IF Receiver
    ​ ​
    ​​The Si4704/05 ICs support worldwide FM bands starting at 64 MHz for Eastern European countries and extending all the way to 108 MHz for the rest of the world. The devices support channel spacing down to 10 kHz, and include advanced, proven seek functionality. Silicon Labs' proven FM receiver expertise is incorporated in the Si4704/05 ICs, gained through thousands of designs with almost every OEM and ODM in the world and more than 100 million devices shipped.
    ​​The Si4704/05 ICs leverage Silicon Labs' internationally patented and proven digital low-IF architecture, offering proven functionality in a simple and mature API. The device is available in a highly-reliable, ultra-small 3 mm x 3 mm x 0.55 mm 20-pin QFN and are layout compatible with the full suite of Silicon Labs broadcast offerings including FM transmit, AM/FM/SW receive, weather band receive, SAME decode and unparalleled RDS data receivers. The complete solution including a minimal BOM requires less than 15 mm2 board area or less than half of competing solutions. The Si4705 ICs incorporates Silicon Labs' proven and widely adopted RDS processor including worldwide compliance, all symbol decoding, error detection, error correction and other RDS functions. The Si4705 RDS functionality is unmatched in the industry for performance, on-chip processing and worldwide adoption.


    Product Matrix





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