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 A at 3V)
• Auto-power down
• Built-in oscillator, D/A converter, EPROM
• ADPCM data compression
• Optional pop noise elimination function
• COUT pin drives speaker with a transistor
• Development tools support
• VOUT1 and VOUT2 drives buzzer directly
• Sampling rate determined by external resistor
• Holdable and unholdable triggering option
• Industrial temperature availableSpecifications
| Symbol |
Parameter |
Value |
Unit |
| VTERM |
Terminal Voltage with Respect to GND |
0.5 to+7.0 |
V |
| TBIAS |
Temperature Under Bias |
40 to +85 |
|
| TSTG |
Storage Temperature |
55 to +125 |
|
Notes:
1. Stress greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability.DescriptionIS22C040 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 from 3.0V to 6.0V. A pair of PWM output pins, VOUT1 and VOUT2 provide direct drive to a buzzer (Figure 2). Voice quality from a buzzer is comparable to speaker output and power consumption is much lower.
A current output pin, COUT, enables the device to drive a 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.
IS22C040 Data Sheet
