UM66 is a pleasing music generator IC which works on a supply voltage of 3V. the required 3V supply is given through a zener regulator. its out put is taken from the pin no1 and is given to a push pull amplifier to drive the low impedance loud speaker. A class A amplifier before push pull amplifier can be used to decrees the noise and improve out put. UM66 is a 3 pin IC package just looks like a BC 547 transistor.

Circuit diagram:
Music Generator Schematic Using UM66
A Continuous Music Generator Circuit Diagram


R1 = 4.7K
C1 = 10uF-25v
D1 = 3.3v Zener
Q1 = SK100
Q2 = SL100
IC = UM66
SP = 8 ohm

Pin out of UM66 IC:
  • Output----Melody Output
  • +Vdd-----Positive power supply
  • -Vss------Negative Power supply

  • Features of UM66T series:
    • 62 Note ROM Memory
    • Voltage rating: 1.3V to 3.3 V
    • Power on reset

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