General Description

The HT812D0 is a single chip LOG-PCM voice synthesizer LSI with 2.8-second voice capacity at 6kHz sampling rate. The chip when triggered drives a speaker through an external transistor with a current switch D/A converter output. Negligible current will be consumed in the standby state.

Features

? Operating voltage: 2.4V~5.0V

? Directly drives an external transistor

? Low standby current (1μA Typ. for VDD=3V)

? Minimal external components

? 124 words table ROM for key functions

? Programmable silence length and end-pulse width (minimal end-pulse width is 330μs at a 6kHz sampling rate)

? 2.8-second voice capacity

? Controllable volume

? FLAG1 options:

– End-pulse output

– 3Hz flash

– 6Hz flash

– Voice output indication

– Busy output

? FLAG2 options:

– 3Hz flash

– 6Hz flash

– Busy output

? Four keys

? Key options:

– Stop key: KEY4

– Random (only for KEY1)

– Sequential (only for KEY1)

– Repeat (for all KEYs, under retriggerable condition)

– Key debounce time (for all KEYs): 700μs, 22ms, 45ms, 180ms (based on a sampling rate of approximately 6kHz)

– One shot (for all KEYs)

– Level-trigger

– Pull-high resistance (for all KEYs)

? Section options:

– Retriggerable

– Non-retriggerable

Applications

? Toys

? Alarm clocks

? Public address system

? Alert & warning system

? Sound effect generators