A. General Description —

The HT–2812 is a C-MOS LSI chip specially designed for the sound effect

application. It contains only one section which include tone circuit, noise cir-

cuit and other control logic to generate many kinds of sound, such as Rifle

Gun, Machine Gun, Booming Sound, Door Bell, Alarm and etc.... Customer’s

sound source can be analyzed and programmed into internal ROM by changing

one mask layer during device fabrication. It is very suitable for various toy

applications.

B. Features —

• Single power supply: 2.4V ~ 3.3V.

• Low stand-by current at 3V, 1µA typically.

• Auto power-off function.

• Speaker or directly buzzer application.

• Built-in envelop control circuit.

• 1Hz~8Hz programmable LED flash output.

• Minimum external components.

C. Block Diagram —

HT— 2812 APR.15.1993

1 SOUND GENERATOR PAGE: 1

D. Pin Assignment —

E. Pad Assignment & Position —

Chip Size : 67 X 72 (mil)2

* The IC substrate should be connected to VDD in PCB layout artwork.

HT— 2812 APR.15.1993

1 SOUND GENERATOR PAGE: 2

Unit : mil

Pad No. Symbol x Y Pad No. Symbol X Y

1 VSS –27.127 32.3 7 VDD 27.528 –32.3

2 OUT –27.127 –32.3 8 KEY 27.528 –24.65

3 OUT –10.127 –32.3 9 OSC2 27.528 32.3

4 ENV –2.307 –32.3 10 OSC1 19.878 32.3

5 TEST3 8.488 –32.3 11 TEST1 12.228 32.3

6 LED 16.138 –32.3 12 TEST2 4.578 32.3

F. Absolute Maximum Ratings — (Ta=25°C)

Parameter Symbol Minimum Maximum Unit

Supply Voltage VDD –0.3 5 V

Input/Output Voltage VI, VO VSS–0.3 VDD+0.3 V

Storage Temperature TSTG –50 125 °C

Operating Temperature TOP 0 70 °C

G. Electrical Characteristics — (Ta=25°C)

Symbol ParameterTest Condition

Min. Typ. Max. UnitVDD Condition

VDD Operating Voltage 3V — 2.4 3 3.3 V

ISTB Stand-by Current 3V — — 1 5 µA

IDD Operating Current 3V No load — 300 600 µΑ

IOH Output Source Current 3V VOH=2.5V –1 –2 — mA

IOL Output Sink Current 3V VOL=0.5V 1 2 — mA

IENV ENV Source Current 3V VOH=2.5V –1 –2 — mA

ILED LED Source Current 3V VOH=2.5V –1 –2 — mA

HT— 2812 APR.15.1993

1 SOUND GENERATOR PAGE: 3

Symbol ParameterTest Condition

Min. Typ. Max. UnitVDD Condition

FOSC Oscillator Frequency — R=330kΩ — 64 — KHz

VIH "H" Input Voltage 3V — 2.1 — — V

VIL "L" Input Voltage 3V — — — 0.9 V

H. Pad Description —

Pad No. Pad Name I/O Description

1 VSS Negative power supply, GND.

2 OUT O Sound output pad, out of phase to pad 3.

3 OUT O Sound output pad.

4 ENV O Sound envelop control pad.

5 TEST3 I For IC test only.

6 LED O LED flash output pad.

7 VDD Positive power supply.

8 KEY I Key input pad, low active.

9 OSC2 O Oscillator output pad.

10 OSC1 I Oscillator input pad.

11 TEST1 I For IC test only.

12 TEST2 I For IC test only.

HT— 2812 APR.15.1993

1 SOUND GENERATOR PAGE: 4

I. Timing Diagram —

(a) With Envelop :

(b) No Envelop :

HT— 2812 APR.15.1993

1 SOUND GENERATOR PAGE: 5

J. Typical Application Diagram —

(a) Example 1: speaker ouput with envelop

HT— 2812 APR.15.1993

1 SOUND GENERATOR PAGE: 6

1

7 2

8

3

9

4

10

5 6

12

HT–2812

8

7

6

5

1

2

3

4

VSS

ENV

OUT

OSC1

OSC2

KEY

VDD

11

Rosc

33µ+ 100Ω

100Ω

VDD

VDD

Rosc

100Ω

8050

VDD

8050

+33µ HT–2812

KEY

VDD

OUT

* The IC substrate should be connected to VDD in PCB layout artwork.

(b) Example 2: speaker output without envelop

HT— 2812 APR.15.1993

1 SOUND GENERATOR PAGE: 7

1

7 2

8

3

9

4

10

5 6

12

HT–2812

8

7

6

5

1

2

3

4

VSS

ENV

OUT

OSC1

OSC2

KEY

VDD

11

Rosc

100Ω100Ω

VDD

VDD

Rosc

100Ω

8050

VDD

8050

HT–2812

100Ω

VDD

OUT

* The IC substrate should be connected to VDD in PCB layout artwork.

(c) Example 3: buzzer output without envelop

HT— 2812 APR.15.1993

1 SOUND GENERATOR PAGE: 8

1

7 2

8

3

9

4

10

5 6

12

HT–2812

8

7

6

5

1

2

3

4

VSS

ENV

OUT

OSC1

OSC2

KEY

VDD

11

Rosc

100Ω

VDD

Rosc

HT–2812

100Ω

Buzzer100Ω

Buzzer

VDD

OUT

* The IC substrate should be connected to VDD in PCB layout artwork.

(d) Example 4: hand touch trigger

HT— 2812 APR.15.1993

1 SOUND GENERATOR PAGE: 9

HandTouch

1

7 2

8

3

9

4

10

5 6

12

HT–2812

8

7

6

5

1

2

3

4

VSS

ENV

OUT

OSC1

OSC2

KEY

VDD

11

Rosc

100Ω

VDD

Rosc

HT–2812

100Ω

Buzzer100Ω

Buzzer

VDD

8050

HandTouch

VDD

8050

VDD

OUT

* The IC substrate should be connected to VDD in PCB layout artwork.

Application Circuit (HT–2812A — Airplane)

HT— 2812A APR.15.1993

AIRPLANE PAGE: 10

1

7 2

8

3

9

4

10

5 6

12

HT–2812A

11

390KΩ

100Ω

VDD

Buzzer 100Ω

KEY

100Ω

VDD

8050

KEY :

OUT :

ENV :

LED :

T = 8 sec

When Fosc = 64KHz

* The IC substrate should be connected to VDD in PCB layout artwork.

Application Circuit (HT–2812B — Rocket)

HT— 2812B APR.15.1993

ROCKET PAGE: 11

1

7 2

8

3

9

4

10

5 6

12

HT–2812B

11

220KΩ

100Ω

VDD

Buzzer 100Ω

KEY

100Ω

VDD

8050

KEY :

OUT :

ENV :

LED :

T = 4.7 sec

When Fosc = 96KHz

* The IC substrate should be connected to VDD in PCB layout artwork.

Application Circuit (HT–2812C — Siren II)

HT— 2812C APR.15.1993

SIREN II PAGE: 12

1

7 2

8

3

9

4

10

5 6

12

HT–2812C

11

390KΩ

100Ω

VDD

Buzzer 100Ω

KEY

100Ω

VDD

8050

KEY :

OUT :

ENV :

LED :

T = 0.45 sec

When Fosc = 64KHz

* The IC substrate should be connected to VDD in PCB layout artwork.

(repeat 15 cycle)

Application Circuit (HT–2812D — Police Car)

HT— 2812D APR.15.1993

POLICE CAR PAGE: 13

1

7 2

8

3

9

4

10

5 6

12

HT–2812D

11

150KΩ

100Ω

VDD

Buzzer 100Ω

KEY

100Ω

VDD

8050

KEY :

OUT :

ENV :

LED :

T = 0.35 sec

When Fosc = 128KHz

* The IC substrate should be connected to VDD in PCB layout artwork.

(repeat 15 cycle)

Application Circuit (HT–2812E — Fire Brigade)

HT— 2812E APR.15.1993

FIRE BRIGADE PAGE: 14

1

7 2

8

3

9

4

10

5 6

12

HT–2812E

11

150KΩ

100Ω

VDD

Buzzer 100Ω

KEY

100Ω

VDD

8050

KEY :

OUT :

ENV :

LED :

T = 4.0 sec

When Fosc = 128KHz

* The IC substrate should be connected to VDD in PCB layout artwork.

Application Circuit (HT–2812G — Siren I)

HT— 2812G APR.15.1993

SIREN I PAGE: 15

1

7 2

8

3

9

4

10

5 6

12

HT–2812G

11

390KΩ

100Ω

VDD

Buzzer 100Ω

KEY

100Ω

VDD

8050

KEY :

OUT :

ENV :

LED :

T = 0.38 sec

When Fosc = 64KHz

* The IC substrate should be connected to VDD in PCB layout artwork.

(repeat 15 cycle)

Application Circuit (HT–2812H — Dialing Tone)

HT— 2812H APR.15.1993

DIALING TONE PAGE: 16

1

7 2

8

3

9

4

10

5 6

12

HT–2812H

11

390KΩ

100Ω

VDD

Buzzer

100Ω

KEY

100Ω

VDD

8050

KEY :

OUT :

LED :

T = 2.5 sec

When Fosc = 64KHz

* The IC substrate should be connected to VDD in PCB layout artwork.

8

7

6

5

1

2

3

4

VSS

ENV

OUT

OSC1

OSC2

KEY

VDD100Ω

VDD

8050

HT—2812H

T = 1.54 sec

390KΩ

OUT

VDD

Application Circuit (HT–2812J — Chicken Sound)

HT— 2812J APR.15.1993

CHICKEN PAGE: 17

1

7 2

8

3

9

4

10

5 6

12

HT–2812J

11

62KΩ

100Ω

VDD

Buzzer

KEY

100Ω

VDD

8050

KEY :

OUT :

LED :

T = 150 sec

When Fosc = 260KHz

* The IC substrate should be connected to VDD in PCB layout artwork.

T = 230 sec

Application Circuit (HT–2812K — Ambulance Sound)

HT— 2812K APR.15.1993

AMBULANCE SOUND PAGE: 18

1

7 2

8

3

9

4

10

5 6

12

HT–2812K

11

390KΩ

100Ω

VDD

Buzzer 100Ω

KEY

100Ω

VDD

8050

KEY :

OUT :

ENV :

LED :

T = 1.9 sec

When Fosc = 64KHz

* The IC substrate should be connected to VDD in PCB layout artwork.

(repeat 3 cycle)