Holtek Semiconductor Inc HT819D0 Datasheet
4.2 Second LOG-PCM Speech
Features
•
Operating voltage: 2.4V ~5.0V
•
Directly drives an external transistor
•
Low standby c urr en t ( 1µ A ty p. for VD D= 3 V)
•
Minimal external components
•
252 words table ROM for key functions
•
Programmable silence length and end-pulse
width (minimal end-pulse width is 330
6kHz sampling rate)
•
4.2-second voice capacity
•
Section options:
–
Retriggerable
–
Non-retriggerable
•
FLAG1 options:
–
End-puls e output
–
3HzB flash
–
6HzB flash
–
Voice output indication
–
Busy output
Applic a tions
•
Toys
•
Alarm clocks
•
Public address system
µs at a
HT819D0
•
FLAG2 options:
–
3Hz flash
–
6Hz flash
–
Busy output
•
Controllable volume
•
6 keys
•
Key options:
–
Stop key: KEY6
–
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 of)
–
One shot (for al l KEYs )
–
Pull-high resistance (for all KEYs)
•
Dice form or 16-pin DIP/SOP
•
Alert and warning system
•
Sound effect generators
General Description
The HT819D0 is a single chip LOG-PCM voice
synthesizer LSI wi th 4.2-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. Negligib le current wi ll be consume d in
the standby state.
The HT819D0 provides 6 key inputs and 2 programmable FLAG outputs. With a 2.4V~5.0V
power supply, a complete synthesized voice
playback system can be ea sily built with very
few external components.
The custome r’s voice s ources are reco rded section by section into an internal mask ROM. The
sectional playback arrangement instructions of
each key are stored in the table ROM. The key
features are also programmable. With such a
flexible structure, the HT819D0 is excellent for
versatile voice applications.
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Pin Assignment Block Diagram
HT819D0
Pad Coordinates
Pad
No.
1 –885.05 522.30 8 1008.85 –710.50
2 –885.05 344.50 9 905.45 660.50
3 –1005.05 –710.50 10 628.05 660.50
4 –229.95 –660.50 11 296.45 660.50
5 62.35 –660.50 12 –333.95 660.50
6 526.75 –660.50 13 –665.55 660.50
7 833.85 –660.50
Chip size: 2290
* The IC substrate should be connected to VSS in the PCB layout artwork.
× 1750 (µm)
2
XY
Pad
No.
Pin Description
Pin No. Pin Name I/O
1 OSC1 I — Oscillator input pin
2 FLAG1 O
3 VSS I — Negative power supply (GND)
4 FLAG2 O
5, 12, 13 NC — — No connection
Internal
Connection
NMOS
Open Drain
NMOS
Open Drain
Description
3HzB/6HzB flash output, busy output, end-pulse
or voice outpu t indication (by code optio n). Open
drain, active low output
3Hz/6Hz flash output or busy output (by code
option). Open drain, active low output
Unit: µm
XY
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HT819D0
Pin No. Pin Name I/O
Internal
Connection
Description
Trigger key, low active. Key features such as
6~11 KEY1~KEY6 I Pull-High
debounce time, pull-high resistance and repeat
are all by mask option.
14 VDD I — Positive power supply
15 AUD O
PMOS
Open Drain
Voice output for driving an external transistor
16 OSC2 O — Oscil lator output pin
Absolu te Maxim um Ratings *
Supply Voltage ............................... –0.3V to 6V Storage T emperature ............... –50°C to 125°C
Input Voltage ............... V
–0.3V to VDD+0.3V Operating Temperature ............. –20°C to 70°C
SS
*Note: These are stress ra tings on ly. Stresses exceeding the range spe cified un der “Abso lute Maxi-
mum Ratings” ma y cause substantial damage to the device. Functional operation of this
device at other conditions beyond those listed in the specification is not implied and prolonged
exposure to extreme condition s may affect device reliability.
Electrical Cha racteristics (Ta=25°C)
Symbol Parameter
V
I
DD
I
STB
I
O
I
OL
V
V
f
OSC
Operating Voltage — — 2.4 — 5.0 V
DD
Operating Current 3V
Standby Current 3V — — 1 3 µA
Max. AUD Output Current 3V VOH=0.6V –1.5 –2 — mA
FLAG Sink Current 3V VOL=0.3V 1.5 3.0 — mA
“H” Input Voltage — — 0.8V
IH
“L” Input Voltage — — 0 — 0.2V
IL
Oscillati ng Frequency 3V R
Test Conditions
V
DD
Conditions
No load,
f
=96kHz
OSC
=530kΩ 76 96 116 kHz
OSC
Min. Typ. Max. Unit
DD
µA
V
—200400
—VDDV
DD
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Functional Description
The HT819D0 is a mask ROM type voice synthesizer with 4 .2-second voice capacity. A group of
pre-recorded voice sections is played upon receipt
of key trigger input signals. Two FLAG signals are
output while playing voices.
The 4.2-second voice capacity can be divided into
sections of arbitrary length. Notice that the silence length and end-pulse width are not included in the memory.
By using HOLTEK’s programming tools, the
contents and arrange ment of sections, as well
as key features and FLAG output are all programmable before device fabrication.
The IC provides 6 key inputs (KEY1~KEY6). Of
the 6 keys, KEY1 can b e optioned as a direct,
sequential or rando m trigger key. KEY6 can be
selected as a stop or direct key. The remaining
5 keys (KEY2~KEY6), are u sed as direct keys
exclusively.
Syste m os c ill ator
The HT819D0 has a built-in RC oscillator
which requires only one external resistor for
normal applications. The oscillator frequency is
typically 96kHz for an external resistor of
530k
Ω. The required oscillator frequency m ay
vary with different sampl ing rates in the pro cess of voice programming. As a result, the value
of the oscillator resistor may be different for
different items.
The oscillator is turned on when triggered by a
key input. After playing, it is immediately turned
off and the chip goes into the standby state.
HT819D0
Play function block diagram
Voice ROM
The voice ROM is originally designed to continuously record the 4.2-second voice data at a 6kHz
sampling rate. A higher sampling rate will generate voices of better playback quality, but will
shorten the total recording time. On the other
hand, a lower sampling rate results in longer
recording time but sacrifice voice quality.
The playback time can be significantly ex tended
by making use of coding efficiency, silence playing,
section repeating, section cascade, et c.
Section
Section is the basic element constituting the
contents of voice RO M. During programming,
the customer’s voice sources can be divided into
as many sections as req uired. A section can be
comprised by a voice or an interval of silence.
However, the silent length is not counted in
voice ROM. The total number of sections included shoul d be le ss t han 252 due t o the spac e
limitation of the function table ROM. T he total
length of the included sections is limited by the
voice ROM.
A section, when triggered by a key input, can be
played once, repeatedly or cascaded with other
sections, depending on the key function table
instructions.
4 6th May ’98
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