IS22C040

Integrated Silicon Solution, Inc.

1

VP009-1C

10/01/98

ISSI reserves the right to make changes to its products at any time without notice in order to improve design and supply the best possible product. We assume no responsibility for any errors which

may appear in this publication. © Copyright 1998, Integrated Silicon Solution, Inc.

IS22C040

32 to 40 SEC INSTANT VOICE ROM

FEATURES

• Voice length at

– 8 KHz sampling is 32 seconds

– 6 KHz sampling is 40 seconds

• Silence compression to save memory

• Eight trigger pins, S1 to S8 for 32 sections

• SBT pin play-all or sequential play-all

• 15 ms debounce time suitable for CDS

• IRP interrupt pin stops playback at once

• STP stop pulse generated at end of playback

• BUSY signal for CPU control

• Two LEDs flash at 3 Hz interval

• 3.0V to 6V single power supply operation

• Low standby current (<5

µA at 3V)

• Auto-power down

• Built-in oscillator, D/A converter, EPROM

• ADPCM data compression

• Optional pop noise elimination function

• Development tools support

• Sampling rate determined by external resistor

• Holdable and unholdable triggering option

• Industrial temperature available

GENERAL DESCRIPTION

IS22C040 is a high-quality voice synthesizer with a capacity

of 32 to 40 seconds. A proprietary ADPCM algorithm is

used. The audio message is stored in a 1024-Kbit on-chip

EPROM.

The IS22C040 eliminates the need of complicated circuitry

in voice playback (Figure 1) but still achieves high voice

quality. Sounds such as human speech, animal sounds,

musical sounds, and even special sound effects can be

synthesized. Devices can be cascaded to achieve longer

voice duration (Figure 3). Two devices can be configured

in parallel (Figure 4) in order to achieve signal mixing

without an external mixer allowing speeches to be mixed

with background music synthesis from two different chips.

The instant programming nature of the IS22C040 allows a

very short production turnaround time. There are no NRE

charges that are usually required with conventional voice

ROMs. Users now can apply a voice synthesis function as

an additional feature to their products even when production

volume is relatively small. It is also ideal for trial or

engineering prototyping. As a result, the initial investment

is minimal and the risk in the product development phase

is reduced.

The IS22C040 provides a wide voltage operating range

quality from a buzzer is comparable to speaker output and

power consumption is much lower.

speaker with a low cost NPN transistor. No complex

filtering or amplifier circuit is needed. An automatic ramp

up/down function eliminates the undesired noise at the

end of playback.

Up to 32 sections are accessible through S1 to S8. The

SBT trigger pin can be programmed to playback all 32

sections or sequentially from section 1 to 32. An interrupt

pin (IRP) and stop pulse (STP) or BUSY signals provide

handshaking with microprocessors or other IS22C040

devices. All trigger pins give 15 ms debounce time and is

ideal for CDS applications as in Figure 6. Two LED drivers

are available, flashing on and off at approximately 3Hz

intervals (Figure 5). The internal voltage compensation

oscillator requires only one external resistor. Different

sampling frequencies are determined by the external

oscillator resistor value.

OCTOBER 1998