A single-chip 1,200 sinusoid real-time generator for additive synthesis of musical signals

This paper presents a new hardware implementation of additive synthesis for high quality musical sound generation. The single-chip configuration is capable of performing 1,200 sinusoid real-time synthesis; the system is expandable to 13,200 partials by series connecting 11 chips. Each sinusoid is generated by a marginally stable second order IIR filter, and its frequency, amplitude and phase can be independently specified. The system is clocked at 60 MHz when working with a 44.1 kHz sampling rate. Two completely independent channels are available as output, and each sample relies on a 20 bit representation to achieve an SNR of at least 110 dB, thanks to the internal 24 bit word length. The IC is designed in a 0.5 μm CMOS technology and has a core area of approximately 19 mm²