FM Module

Compact sized SMD based FM Modules are now available to make FM stereo with USB provision. These FM modules are excellent circuit boards which can operate at 5 volt DC. It is also remote operated and the output can be connected to a power amplifier or VCD player. It has a Digital display to show the different functions like Mode, Channel, Volume etc. It also has SD card reader. It is low cost and reliable and can be wired easily. But it is necessary to know the PCB points to wire the board . This note will help you to make your FM receiver.

The circuit board is available as Pre assembled board with connecting wires. It is necessary to connect Remote Sensor (TSOP 1738), USB socket and Amplifier with Speaker.

The circuit requires 5 Volt regulated power supply. If the power supply is not well regulated or with ripples, performance of the circuit will be poor. Regulated power supply can be obtained from a 9 volt transformer and 7805 Voltage regulation IC. The power supply circuit is shown below. The Amplifier can be powered from the 9V unregulated DC available from the point connecting Pin 1 of the Regulator IC.

On the PCB, there are markings for wire connections and wire sets are provided along with the kit. The markings on the back of the PCB are :

BEL 1895 Low Power Mono Amplifier


To make a compact unit use the IC BEL 1895 which can give 1 W output to drive a small speaker. The circuit given is a Mono Amplifier. If you need stereo, assemble two similar amplifier circuits. Alternately you can use a Pre assembled amplifier board. IC BEL 1895 works between 3- 5 volts.

LA 4440 High Power Stereo Amplifier

If high output is necessary, the Module can be connected to a Power Amplifier. The 20 Watts LA4440 Stereo power amplifier circuit is given below. The FM module has outputs for Left and Right channels so that the input to Amplifier can be given through a 10 K Lin (Linear) Dual volume control.

Use a 10 K Lin Dual volume control between the output lines (L and R) of the module and the amplifier. Set minimum volume (2 to 4) in the module using remote and adjust 10 K pot to get clear sound from the speaker. Then increase the volume using remote to the required level. The module can give 1 to 50 range volume.

Volume Control Connection


Antenna is necessary if the signal strength is weak .Connect 30 cm plastic wire to the point ANT on the PCB.

Remote less operation
On the PCB, connections V+, PM, CH V-, P etc are given to connect membrane switches for manual operation.


The FM board has delicate components. Connect wires carefully. To get FM stations programmed, first use a long plastic wire ( 3 meters) as antenna. There is a point in the board ANT to connect antenna. If you scan FM stations using the Scan button of Remote, it will automatically search all the available stations and save the stations as P1, P2, P3 etc. After that, a short piece of wire (30 cm) is sufficient for antenna.  You can also use a Telescopic antenna.

 Note:  If there is a hum from the speaker, not connect the Gnd wire of output in FM module .Connect only two lines – Output from Module to the first pin of Volume control and Input to the amplifier from the second pin of volume control. Third pin of volume control is ground connection.

FM Module with Front Panel

FM Module having front panel with fixed USB socket and SD card reader, mp4, video boards etc is also available.


Pin connection of these modules is given below

The FM board is manufactured by VIRE SILICON CO., LTD.
Data source
For more details:

9 thoughts on “FM Module

  1. Most of the details are available since years from usbthree website. Will you please provide more details regarding MP4, video and other extensions for the circuit board? Better discuss the Circuit designing of the board in detail.
    Thanks a lot

    1. Hello Actually no data is available regarding the circuit design of the FM module. The kit available has no diagram or explanation of working or even the wiring connection diagram. I purchased one kit and faced difficulties while setting the device. That is why I posted the article to help others after I made the unit successfully. The unit uses SMD components and chips.The number of IC is unique which is made for the unit only and not available. So replacement is not possible. It is just like a use and throw thing.Still it is a low cost one doing good jobs.

  2. hi mohan sir, the la4440 can output only 6W into both channels, and 20W (19W infact) (with THD10%) can be delivered only in bridge mode, but it will be mono. here is the datasheet La4440.Pdf

    1. LONEZIDDIK, hope you too give some more details of improving the circuit or doing some more gadgets with this board. I appreciate your effort to correct all the flaws.

      1. Vhhp, i purchased the fm board about 1 year ago to put it in my 5.1 amplifier project and i still use it, it will load 1999 songs (Max), the only bad thing which i found is the fm radio is weak, i mean i don’t get clear signals out of this thing even though i hav trie a long wire as antenna,

    2. You are correct. In bridge mode only it can give 20 watts. 6 W stereo is sufficient to make an amplifier for the FM Module. If you want you can use a power amplifier .

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