Si4703 FM Radio Receiver Hookup Guide

Contributors: Toni_K
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Hardware Overview

Heads up! This tutorial was written for Si4703 FM Tuner Evaluation Board V13 (WRL-12938). The 3.3V and GND pins are switched in the new revision. Make sure you connect to the correct pins for power if you are using an older version like V11 (WRL-10663) or the breakout board.

version 13 Version 11
V13 V11 (Retired)

The Si4703 Breakout Board breaks out multiple pins from the IC. For the power bus, the 3.3V and GND pins are broken out. Keep in mind that while the IC is tolerant up to 5V, the communication pins are only 3.3V tolerant, and therefore should only be used in 3.3V systems. If you need to use this in a 5V system, check out our tutorial on using logic level converters.

Back of Si4703 Breakout Board

Underside of breakout board showing pin labels

For communication, the breakout board provides access to SDIO and SCLK for I2C communication. The RST pin is also broken out for ease of resetting the module.

SEN is also broken out, and enables the user to change the mode of functionality of the IC. SEN is pulled high on the breakout board to enable I2C communication as mentioned previously. However, by changing the state of SEN along with SDIO, you can change the mode of functionality between a 3-wire interface and 2-wire interface.

Finally, the last two pins broken out are the GPIO1 and GPIO2 pins. These can be used as general input/output pins, but also can be used for things like the RDS ready, seeking or tuning functions.

The board does not have a built-in antenna on it. However, by using headphones or a 3 foot-long 3.5mm audio cable, the wires will function as an antenna and will therefore negate the need for an external antenna on the board. If you are not planning on using either of these, you will need to modify the board to add in an antenna.