ALFA R AS3394E - mP Controllable Synthesizer Voice on a Chip

via ALFA R

"The AS3394E is a complete analog music synthesizer voice-on-a-chip intended for software control by a microprocessor system. Included inside the compact 24 pin package is fully temperature compensated, wide range, voltage controlled oscillator providing suboscillator, triangle, sawtooth, and pulse waveforms; a voltage controlled mixer for adjusting the balance between the internally generated VCO waveforms and any external signal; a dedicated four-pole low-pass voltage controlled filter with voltage controlled resonance; a modulation amount VCA for modulating the filter frequency by the triangle waveform output of the VCO; and a final VCA for allowing the output to be enveloped. Envelope control for both the VCF and final VCA may be provided by either a hardware envelope generator such as the AS3310 or through software.

Ranging between -4 and +4 volts, all eight control inputs are provided with internal very high input impedance, low bias current buffers. Thus interface to a microprocessor system may be accomplished simply with a single DAC, 4051-type CMOS multiplexer, and 8 hold capacitors.

Requiring a bare minimum of other external components, the AS3394E is ideal for polyphonic or polytimbric musical instruments featuring rich, analog sound.

FEATURES

- Complete synthesizer Voice on a Chip
- Sample & Hold buffers on-chip for easy interface to a uP
- Fully temperature compensated VCO
- Independently selectable VCO waveforms
- Suboscillator output
- Separate saw output
- Separate vco and filter sections allowing design flexibility
- Constant Loudness vs Resonance VCF
- Rich Sounding VCF Design
- Filter FM routing for more Timbres
- Low Noise, Low Feedthrough VCA
- Few External Components"