General Description

The HT818D0 is a single chip LOG-PCM voice synthesizer LSI with 22.4-second voice capacity at a 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: 3.6V~5.0V

• Directly drives an external transistor

• Low standby current (1μA typ. for VDD=3V)

• Minimal external components

• 508 words table ROM for key functions

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

• 22.4-second voice capacity (based on a 6kHz sampling rate)

• Section options

- Retriggerable

- Non-retriggerable

• FLAG1 options

- End-pulse output

- 3HzB flash

- 6HzB flash

- Voice output indication

- Busy output

• FLAG2 options

- 3Hz flash

- 6Hz flash

- Busy output

• Controllable volume

• 12 keys

• Key options

- Stop key: KEY12

- Random (only for KEY1)

- Sequential (only for KEY1)

- Repeat (for all KEYs)

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

- One shot (for all KEYs)

- Level-trigger

- Pull-high resistance (for all KEYs)

• Dice form or 20/24-pin DIP/SOP package

Applications

• Leisure products

• Alarm clocks

• Public address system

• Alert and warning system

• Sound effect generators