Melody generator IC handles 16 harmonies at once

A Rohm Electronics product story

Edited by the Electronicstalk editorial team Oct 22, 2001

A miniature, low-power sound generator IC from Rohm is optimised for mobile phone handsets where it provides a single-chip solution for the output, customisation and download of ring tones.

A miniature, low-power sound generator IC from Rohm is optimised for mobile phone handsets where it provides a single-chip solution for the output, customisation and download of ring tones.

Rohm's BU8772KN melody generator IC can generate up to 16 simultaneous harmonies and offers 128 tones.

The device can also output 47 drum sounds and 32 different sound effects as well as providing DTMF tones through a built-in DTMF generator.

Incorporating a serial interface for direct microprocessor control, the BU8772KN IC features an integrated sequencer that minimises the processing load on the handset CPU.

A FIFO buffer allows for the download of music data, while Rohm's patented pseudo square wave implementation maximises performance and minimises distortion from the small loudspeakers used in phone handsets.

The new IC, which has a built-in two-dimensional filter, allows for the selection of sine or square wave outputs for maximum effect and offers envelope fade-in and fade-out and independent control of tone volume.

Stereo output is supported through a built-in stereo sound DAC, while master clock frequency is selectable between 12 and 20MHz.

Supplied in a miniature QFN28V package measuring just 5.0 x 5.0 x 0.8mm, the BU8772KN operates across a wide supply voltage of 2.7 to 3.6V.

A power down mode ensures minimum power consumption when the IC is inactive.