Adaptive pulse coding speech synthesis series

The adaptive pulse code modulation method changes the digital quantity according to the speech analog signal conversion rate, that is, in the pulse code modulation method. Change its quantization amplitude accordingly. usually. The sound quality of synthesized speech using adaptive pulse code modulation is better than that of digital pulse code modulation. This speech synthesis method mainly uses external memory to form the voice interface of a long-term voice broadcast system or other products. The picture shows a typical application circuit of the HT83XXX series. The figure below shows the application circuit diagram of HT82013. HT82013 has a 20-level binary counting and 3-select output speech synthesis circuit. It adopts 24-pin dual-in-line plastic packaging. The power supply voltage is 3.5V~5V, the operating current is 2.8mA, and the quiescent current is 5μA. HT82013 is a speech synthesis circuit with external EPROM, which can be connected to 3 X 8MB EPROM. The voice length can be up to 1368 seconds.