UM66T is a melody integrated circuit. It is designed for use in bells, telephones, toys etc. It has an inbuilt tone and a beat generator. The tone generator is a programmed divider which produces certain frequencies. These frequencies are a factor of the oscillator frequency. The beat generator is also a programmed divider which contains 15 available beats. Four beats of these can be selected.
There is an inbuilt oscillator circuit that serves as a time base for beat and tone generator. It has a 62 notes ROM to play music. A set of 4 bits controls the scale code while 2 bits control the rhythm code. When power is turned on, the melody generator is reset and melody begins from the first note. The speaker can be driven by an external npn transistor connected to the output of UM66.
Features
- One shot or level hold mode
- Plays a melody consisting of 62 note
- RC oscillator on chip
- 62-note ROM memory
- Sound range : 2 octaves
- Tempo : 15 kinds (presto-largo)
- Direct Piezo drive
- Solutions of automatic stop or repeat of the melody
- Dynamic speaker can be driven with external NPN transistor
- Power on reset : melody gegins from the frist note
