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Description: This is a very small FM transmitter. Designed to be the building block of wireless microphones and MP3 broadcasters, this small module requires only two external components and utilizes a completely digital interface.

This part is meant for research purposes and is not FCC certified. The NS73M part is not certified by itself (certification requires an antenna be attached) but has been used and certified in many consumer products.

Breakout board available below.


  • 87.5MHz to 108MHz
  • Stereo multiplexing modulation
  • Simple external 32.768kHz
  • Small size
  • Alignment free
  • SPI and I2C supported interfaces
  • 2.7V to 3.6V
  • -20C to 75C operation

Dimensions: 7x7x1.5mm

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Customer Comments

  • why is this categorized as retired?

    • The IC wasn’t selling well enough on its own to justify keeping it on the storefront. However, we do still have the breakout board available here.

  • Just noticed the IC is not available; the BOB is, but the IC by itself is not. Is Sparkfun not planning on carrying the IC anymore?

  • Has anyone tested this w/ video? I’m assuming that the chip does FM modulation of any analog source, and ntsc video would be on that list :-).

    If I don’t hear an update soon I’ll probably be responding to myself in a little while……

  • Well 2 years is nothing between friends;
    ‘data’ on FM = RDS (radio data system) lives on a 56KHz sub-carrier which would be injected prior to FM modulation, so looking at this chip datasheet there is no possibility.
    The chip has the Stereo ‘Zenith GE’ coder on board and the RF element, so yeah plug it in add a 32KHz crystal (for some reason) and go.
    Warning Rant Alert: - FM ! Gee, the last of the last in the analogue World. Deeply sad that broadcast radio companies couldn’t get their act together to replicate it’s performance in the digital domain.

    • IMHO it would be better to have here a SI4711 (with a breakout board), it has also RDS and digital audio interface!
      It would be very useful to make in-car gadget.
      Silabs only sell the complete evb which costs 160$

  • So, for a newbie such as myself, how would one implement this, say, in a netbook for built-in FM transmission?
    Or in any project, for that matter?
    How do you drive this? There must be more to it than L, R, and gnd (and the crystal+cap).

  • Does this chip also do Digital data transmission…. like the song titles and station info we see on some of the better FM Receivers?

    • Good question. I don’t know. I don’t think the IC is made to transmit data in the background - it’s only got audio paths.

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