HT2844
4-Sound Generator
Features
•
•
•
Single power supply: 2.4V~3.3V
Low standby current: 1
µ
A (Typ.)
at V
DD
= 3V
Auto power-off function
•
•
•
•
Eight different sound sections
Speaker or direct piezo application
LED flash drive output
Minimal external components
General Description
The HT2844 is a CMOS LSI chip designed for
use in sound effect products. It is equipped with
tone circuit, noise circuit, and other control
logic to generate various sounds including rifle
fire, machine gun, booming, door bell, Alarm,
and so forth. Customer’s supplied sound source
can be analyzed and programmed into an inter-
nal ROM by changing a mask layer during de-
vice fabrication. The HT2844 is suitable for
various toy applications.
Pin Assignment
Pad Assignment
Chip size: 81
×
67 (mil)
2
* The IC substrate should be connected to VDD
in the PCB layout artwork.
1
11th July ’97
HT2844
Block Diagram
Pad Coordinates
Pad No.
1
2
3
4
5
6
7
Unit: mil
X
–33.53
–33.53
–33.53
–33.53
–16.96
–7.43
2.51
Y
27.05
18.30
10.22
–14.34
–27.04
–27.04
–27.04
Pad No.
8
9
10
11
12
13
14
X
12.45
22.40
33.62
33.62
33.62
–17.17
–24.86
Y
–27.04
–27.04
5.72
18.38
27.05
27.05
27.05
Pin Description
Pin No.
1
2
3
4
5
6
7
8
9
10
11
Pin Name
TEST2
VDD
NC
NC
OUT
OUT
VSS
TEST1
TEST3
OSC2
OSC1
I/O
I/O
—
—
—
O
O
—
I
I/O
O
I
For IC test only
Positive power supply
No connection
No connection
Sound output
Description
Sound output, out of phase to pin 5
Negative power supply, GND
For IC test only
For IC test only
Oscillator output
Oscillator input
2
11th July ’97
HT2844
Pin No.
12
13
14
15
16
Pin Name
KEY1
KEY2
KEY3
KEY4
LED
I/O
I
I
I
I
O
KEY1 input, low active
KEY2 input, low active
KEY3 input, low active
KEY4 input, low active
LED flash output
Description
Absolute Maximum Ratings*
Supply Voltage ................................. –0.3V to 5V
Input Voltage.................... V
SS
–0.3 to V
DD
+0.3V
Storage Temperature................. –50
°
C to 125
°
C
Operating Temperature................... 0
°
C to 70
°
C
*Note: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent
damageto the device. These are stress ratings only. Functional operation of this device at
these or any other conditions above those indicated in the operational sections of this
specification is not implied and exposure to absolute maximum rating conditions for extended
periods may affect device reliability.
Electrical Characteristics
Symbol
V
DD
I
STB
I
DD
I
OH
I
OL
I
LED
F
OSC
V
IH
V
IL
(Ta=25
°
C)
Parameter
Operating Voltage
Standby Current
Operating Current
OUT Source Current
OUT Sink Current
LED Source Current
Oscillator Frequency
“H” Input Voltage
“L” Input Voltage
Test Conditions
V
DD
—
3V
3V
3V
3V
3V
—
3V
3V
Min.
2.4
—
—
–1
1
–1
—
2.4
—
Typ.
3
1
300
–2
2
–2
128
—
—
Max.
3.3
5
600
—
—
—
—
—
0.6
Unit
V
µ
A
µ
A
Conditions
—
—
No load
V
OH
=2.5V
V
OL
=0.5V
V
OL
=2.5V
R=220k
Ω
—
—
mA
mA
mA
kHz
V
V
3
11th July ’97
HT2844
Timing Diagram
4
11th July ’97
HT2844
Application Circuits (HT2844 — Four Toy Gun Sounds)
•
Speaker application
5
11th July ’97
