API840N

Features:

* Voice length at
    - 8 KHz sampling is 32 seconds
    - 6 KHz sampling is 40 seconds
* Silence compression to save memory
* Eight trigger pins,TG1 to TG8 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 internal
* 3.0V to 6V single power supply operation
* Low standby current (<5 mA 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 available


Pinout




Specifications

Symbol	Parameter	Value	Unit
VTERM	Terminal Voltage with Respect to GND	-0.5 to +7.0	V
TBIAS	Temperature Under Bias	-40 to +85	°C
TSTG	Storage Temperature	-55 to +125	°C

Description

API840N 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 API840N 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 API840N 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 API840N 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 TG1 to TG8.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 API840N 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.