UM66 Musical Generator IC

The UM66 series are CMOS IICs designed for use in calling bells, phones, and toys. It has a built-in ROM program for playing music. The device has very low power consumption. Thanks for the CMOS technology. The melody will be available at pin 3 of UM66 and here it is amplified by using Q1 to drive the speaker. Resistor R1 limits the base current of Q1 within the safe values. Capacitor C1 is meant for noise suppression.

The power supply must be between 1.5V & 4.5V. Do not exceed 4.5 V.

The speaker can be driven with an external NPN transistor.

Melody begins from the first note if the power is reset.

Assemble the circuit on a good-quality common board.

If transistor HE8050S is not available use any NPN transistor like BC548 or 2N2222.