Page 1
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.
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HT819D0
The following are examples of section division:
In addition, a section can be set as retriggerable
or non-retriggerable de pend ing on the code option.
•
Retriggerable
When the currently p laying section is set as
retriggerable, it will stop im mediately upon
receipt of other key inputs.
•
Non-retriggerable
When the currently playing section is selected
as non-retriggerable, it will go on playing till the
whole section is completed, whether or not there
is a key input in the process of playing.
For a key group, some sections can be set as
retriggerable and some as non-retrigge rable.
When a retriggerable section of a key group is
playing, any key can be triggered to interrupt
its playing. On the other hand, if it is a nonretriggerable section playi ng, any key interrupt is ignored.
Group
The HT819D0 plays groups according to the key
input. A group can be made up of on e or more
sections. When a key is triggered, the corresponding group is played. For example, triggering KEY2 plays group 2, and so on. The same
section is allowed to appear in different groups.
However, KEY1 can be made up of multiple
groups when it is optio ned as a sequential or
random key. Otherwise, each key is comp rised
by one group only.
Key function table
The sections included in the voice ROM are
played according to th e instructions of the key
function table. The function table contains
group information as wel l as playing order of
sections in the groups. Notice that the total
number of sections included in the groups
should be less than 252–the space limitation of
the function table ROM.
•
KEY1 as a direct key
Each key is mapped to a group in the function
table. If a key is not used, the group mapped
to that key is a piece o f sil ence. The following
is an example of the function table:
Group 1 sec.1 + sec.2 + sec.3 + sec.5
Group 2 sec.3
Group 3 sec.2 + sec.2 + sec.3 + sec.4
Group 4 sec.5 + sec.3
As illustrated in the above table, the voice
ROM is composed of 5 secti ons and the function table of 11 sections. I f KEY1 is momentarily triggered, section 1, section 2, section 3
and section 5 are played in sequence and then
stops. Triggering KEY2 plays section 3, and so
on.
•
KEY1 as a sequen tial or random key
When KEY1 is opti oned as a se quen tial o r ran-
dom key, it can include multiple groups (subgroups) in the function table. However, the
remaining 5 keys (KEY2~KEY6) are used as
direct keys exclusively and comprise only one
group in the function table.
An example is show n below:
Group 1-1 sec.4 + sec.2
Group 1-2 sec.1 + sec.3
:
:
:
:
Group 1-N sec.2 + sec.3
Group 2 sec.2 + sec.3
Group 3 sec.3 + sec.5
Group 4 sec.1 + sec.5 + sec.2
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HT819D0
As indicated on the table, KEY1 can be made
up of sub-groups. Each time KEY1 is triggered, the corresponding sub-groups are
played in sequence.
♦
The playing sequence of sequential KEY1 is:
Group 1-1
→ Group 1-2 → Group 1-3 ..... →
Group 1-N (the last group) →Group 1-1 .....
♦
The playing sequence of random KEY1 is:
Group 1-3
→ Group 1-5 ..... → Group 1-N →
Group 1-3 → Group 1-5 .....
That KEY1 functions as a random key is a
special case of sequential key , which combines
a particular arrangement of sub-group playing sequence.
♦
Reset of KEY1 playing sequence
If a sub-group of KEY1 group is being played
and one of KEY2~KEY6 is triggered, the
playing sub-group will be terminated, and
the newly triggered key group is played instead. The first sub-group will start playing
when KEY1 is retriggered. In other words,
the KEY1 playing sequence is reset whenever a key other than KEY1 is triggere d (see
Figure 1).
♦
Sub-group selection
When KEY1 is triggered with pulses, the desired sub-group can be selected by controlling
its corresponding pulse number . However, the
features of KEY1 have to be set in the following ways:
–
sequential or random
–
retriggerable
–
minimum key debounce time
(
≅700µs, f
OSC
=96kHz)
For instance, if sub-group 1-3 is the previous
playing group, sub-group 1-5 will start playing
after 2 pulses are appli ed to KEY1, an d so on.
To make easy selection of KEY1 sub-groups,
one of KEY2~KEY6 should be programmed as
silence. Then this silence key has to be triggered to reset KEY1. By so doing, the playing
sub-group is directly specified by the pulse
number applied to KEY1 (see Figure 2).
•
KEY6 as a stop key (by mask option)
When KEY6 functions as a stop key , any voice
output can be stopped by pressing KEY6.
•
KEY1~KEY5 as a repeat key
KEY1~KEY5 all function as a repea t key if
one of the 5 keys is set as a repeat k ey . In other
words, once the m ode of one of KEY1~KE Y5
is determined, the remaining four keys are set
accordingly .
As a repeat ke y, the se ctions incl uded ca n be
played sequentially and repeatedly till key
input is triggered. KEY 6 has no other choice
Figure 1 Reset of KEY1 playing sequence
Figure 2 KEY1 sub-group selection
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HT819D0
but functions as a stop key when KEY1~KEY5
are set as repeat keys.
Key features
•
Key priority
When two or more keys are triggered simulta-
neously , the output voice is determined by the
key priority as shown below:
KEY1>KEY2>......KEY5>KEY6
•
Key debounce time
There are four kinds of key-in debounce time
that can be selected by mask option, namely,
700
µs, 22ms, 45ms and 180ms. The key de-
bounce time varies with the value of the system
frequency .
•
Pull-high resistance
Four kinds of key inp ut pin pu ll -hig h resis-
tance can be selected by mask option,
namely, 20k
Ω, 50kΩ, 100kΩ and 200kΩ.
The resistance may vary with VDD, temperatures and the chip itself due to process
variations.
•
Trigger mode
All of the six keys are internally set as one-
shot trigger mode.
When the FLAG1 and FLAG2 pins are optioned as 3HzB and 3Hz outputs, they will be
alternately output at a 3Hz rate.
•
6Hz/6HzB flash
When voices are playing, the FLAG1 as well as
FLAG2 pin outputs a 6Hz signal to drive an
LED. The signal is active low, 25% duty. Once
the voice output is terminated, the FLAG1 and
FLAG2 pins becomes floating outputs. When
the FLAG1 and FLAG2 pins are optioned as
6HzB and 6Hz outputs, they will be alternately output at a 6Hz rate.
FLAG
When voices are playing, both FLAG1 and
FLAG2 pins are activated to output one of the
following signals through code option.
FLAG1 can be o ptione d as on e of the fo llowing
signal outputs:
None, 3HzB flash, Busy, 6HzB flash, Voice indicator , or End-pul se output
FLAG2, on the other hand, can be set as one of
the following signal ou tputs:
None, 3Hz flash, 6Hz flash, or Busy output
•
3Hz/3HzB flash
When voices are playing, the FL AG1 as well
as FLAG2 pin outputs a 3Hz signal to drive an
LED. The signal is active low, 25% duty. Once
the voice output is terminated, the FLAG1
and FLAG2 pins become floating outputs.
•
Busy output
When a voice group is playi ng, the ou tputs of
both FLAG1 and FLAG2 are turned low , indicating that the chip is busy.
In addition to the above-stated output signals,
FLAG1 can also generate one of the following
signals by code option:
7 6th May ’98
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HT819D0
•
Voice indicator output
FLAG1 is active low when voices are playing.
FLAG1 is also turned low when a voice section
is output. FLAG1 becomes a floating output
after the silence section is output or the voice
output is terminated.
•
End-pulse output
The FLAG1 pin ou tputs an active low pulse
when the voice output is completed. The pulse
width can be programmed depe nding on the
customer’s requirements.
The FLAG1 as well as FLAG2 pins are both
floating outputs when the chip is in the
standby state.
Volume control
The function of volume control can be set by
mask option. A code is written in th e function
table for the purp ose of contro lling the vol ume
of each section output after the volum e control
function is chosen. There are two volume options, namely, full range and half range.
AUD
The AUD pi n is a PM OS op en dra in stru cture.
It outputs voice signals to drive a speaker
through an external NPN transistor when the
chip is active. The AU D pin b eco mes a flo ating
output when the chip is in the standby state.
The 8050 type trans istor with h
≅150 is rec-
FE
ommended for an output driver.
Timing Diagram
One key operation
•
Sequential-retriggerabl e
•
Sequential-nonre triggerable
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•
Random-retriggerable
•
Random-nonretriggerable
Note: Group 1-N may be any of the KEY1 groups
Multi-key operation
•
Retriggerable
HT819D0
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•
Non-retriggerable
•
Repeat
Note: M, N=1:6
HT819D0
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Application Circuits
General application
Parallel application
HT819D0
Cascade or external driving
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Power- on play (one sho t)
Power-on play (continuous)
HT819D0
With volume adjustment
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HT819D0
Push-pull output
To preven t the spe aker and drive r transistor from damage due to exce ss power con sumption which
results from a high voltage power supply (4.5V~5.5V), the following push-pull output stage is
recommended.
Coupling to power amplifier
Standard Item List
Item Name R
HT819D1 Animal Voice 460kΩ
13 6th May ’98
OSC
Remarks
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