Melody Generator using IC UM66

melody genrator ic

Melody Generator Circuit

In this simple project we are going to make a melody generator circuit  using the IC UM66. This ic (UM66) has an inbuilt beat and tone generator. It has three legs like a transistor. This IC (UM66) has many versions with different sounds. This circuit is very useful for the basic hobby students.

melody genrator ic


The  UM….. series are  designed for using in calling bell, cell phones and toys. It has a built-in ROM programs for music. This device has very low power consumption.  The melody is generated at pin 3 of UM66 IC and here it is amplified by using transistor (T1) to drive the speaker. This can generate music without transistors but voice will b very low. Resistor R1 limits the base current of T1 within the safe values. Capacitor (C1) is meant for noise suppression.

UM66 melody genrator ic


  • Do not exceed 4.5 V. Power supply  must be between 1.5V & 4.5V.
  • For loud melody Speaker can be driven with external NPN  transistor.
  • Melody begins from the first if power is reset.
  • For better result circuit should be on a good quality common board.
  • Melody can be generated without transistor.


  • Capacitor 1uF 16v
  • UM66 IC
  • Speaker /buzzer
  • Resistor 4.7k
  • Power supply – 1.5-4.5V DC
  • BC 547  or any NPN transistor

Circuit Diagram without Transistor

The circuit can be used without any extra transistor. Music can be generated using the ic. Anyhow, transistor is used to make melody in loud voice. The circuit  Diagram without any transistor is given below.

Music genrator ic


Circuit Diagram

In this circuit we have used extra transistor and commonly used transistor.

Song or Melody Generator Circuit using IC UM66TXX

Working Of Melody Generated Circuit

The working of the circuit is very simple. We have used UM66 a Happy Birthday Tone Generator IC in the circuit and you can change with any other ICS in the given below list. The operating voltage of the circuit is around 1.5 to 4.5v DC, so We have used a 3v battery to power the circuit given above.

Output of this IC was then fed into the base of the transistor BC547 to drive the speaker connected to the collector of the TransistorT1. Here a Transistor BC547 works fine and a R1 4.7k  resistor is used to limit the current to the base of the transistor T1.


The UM66TXX series is designed specifically for generate melody, tone generation circuits. It consists of a chip ROM programmed with a particular or tone. The IC UM66TXX consumes low power since it was produced by CMOS technology. Last two digits of ic specified tone/ melody. The list of some common tone generator IC and their equivalent numbers.

  • UM66T01 – Jingle bells, Santa is coming to town, and We wish you a merry Xmas
  • UM66T02 – Jingle Bells
  • UM66T04 – Jingle Bells, Rudolph the red-nosed reindeer and  Joy to the world
  • UM66T05 – Home sweet home (a nice melody)
  • UM66T06 – Let me call you Sweet heart
  • UM66T08 – Happy Birthday 2 you
  • UM66T09 – Wedding march
  • UM66T11 – Love Me Tender and Love me True
  • UM66T13 – Easter Paradise
  • UM66T19 – For Elise
  • UM66T32 – Waltz
  • UM66T33 – Mary Had a little Lamb
  • UM66T34 – The train is Running fast
  • UM66T68 – It is a small world

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