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