SM1155 - Nippon Precision Circuits, Inc.

SM1155 series

NIPPON PRECISION CIRCUITS—1

NIPPON PRECISION CIRCUITS INC.

Melody LSIs

OVERVIEW

The SM1155 series are CMOS melody LSIs that, together with a battery and piezoelectric buzzer, operate in

one of 3 melody modes determined by bonding options. They also feature an oscillator stop function in non-

play mode and a variable pull-down resistance function that responds to input levels in order to reduce power

consumption, reduce cost, and extend battery life, making them ideal in a wide range of applications including

the hold sound for telephones and toys.

FEATURES

■

Requires few external components

■

1.2 to 3.6V wide operating voltage range

■

Low power consumption

■

3 melody modes (bonding option)

■

Oscillator stop function in non-play mode

■

Power saving pull-down resistor built-in

■

RC oscillator circuit

■

Power-ON initialization function

■

Wide pitch dynamic range (G

to D

)

■

8-pin SOP package

ORDERING INFORMATION

PINOUT

(Top view)

PACKAGE DIMENSIONS

(Unit: mm)

Device Package

SM1155

×××

8-pin SOPSM1155

×××

SM1155

×××

VSS OUT

3OUT

VDD

4.4 ± 0.2

6.2 ± 0.3

5.2 ± 0.3

0.695typ

1.5 ± 0.1

1.27

0.4 ± 0.1 0.12 M

0.10

0.05 ± 0.05

0.15 − 0.05

+ 0.1

0.4 ± 0.2

0 to 10

SM1155 series

NIPPON PRECISION CIRCUITS—2

PAD DESCRIPTION

SPECIFICATIONS

Absolute Maximum Ratings

Electrical Characteristics

= 25

C, V

= 0V, V

= 1.5V

Number Name i/o Function

1T2

– Test pins (must be open)

2T1

3TGip

1. Built-in pull-down resistor (the resistance of the pull-down resistor varies with the applied voltage, as described in the Electrical Characteristics).

Melody mode control input

4 VSS – Ground

5 OUT oPiezoelectric speaker driver outputs. Both pins are LOW in non-play mode. OUT is LOW and OUT is HIGH

during output for a musical rest note. Both pins are HIGH during the gap between musical notes.

6 OUT

7 V DD – Supply. The rear surface of the chip is V

level.

8 T C – Test pins (must be open)

Parameter Symbol Condition Rating Unit

Supply voltage range V

−

0.3 to 5.0 V

Input voltage range V

−

0.2 to V

+ 0.2 V

Operating temperature range T

opr

−

20 to 80

Storage temperature range T

stg

−

55 to 125

Parameter Symbol Condition Rating Unit

min typ max

O pe rating voltage V

1.2 1.5 3.6 V

Current consumption

1. Measurement circuit

DD1

Non-play mode – 0.01 0.3 µA

Current consumption

DD2

Melody modes: OUT, OU T open – 25 50 µ A

T G LO W-level input voltage V

––V

+ 0.2 V

TG HIGH-level input voltage V

– 0.2 – – V

T G L O W-level input current I

= 0.4V 1.4 3.0 6.0 µ A

TG HIGH-level input current I

= 1.5V 1.4 3.0 6.0 µ A

OUT, OUT L OW-level output current I

= 0.75V 2.0 – – m A

OUT, OUT HIGH-level output current I

= 0.75V 2.0 – – m A

Internal oscillator frequency f

OSC

= 50kHz –20 – +20 %

SM1155

×××

1 S L evel hold 1

SM1155

×××

2 S L evel hold 2

SM1155

×××

3S One-shot

L/open SM1155

×××

1S/ 2S/ 3S Non-play

VDD

VSS

1.5V

2. Measurement circuit

VDD

TG VSS

1.5V

SM1155 series

NIPPON PRECISION CIRCUITS—3

FUNCTIONAL DESCRIPTION

Melody Modes

When TG goes HIGH (V

), melody play starts.

Level hold 1 (SM1155

×××

1S)

When TG goes HIGH, melody play starts and continues while TG is held HIGH. When TG goes open circuit or

LOW, melody play stops, even if during mid melody.

Level hold 2 (SM1155

×××

2S)

When TG goes HIGH, a single melody play starts. Melody play continues until the single melody ends or TG

goes open circuit or LOW, whichever occurs ﬁrst.

1 TUNE

Oscillator

REPEAT REPEAT

OUT

500kΩ135kΩ135kΩ

Pull-down resistance

(2-pin parallel resistance)

1 TUNE

Oscillator

OUT

1MΩ270kΩ

Pull-down resistance

270kΩ1MΩ270kΩ

SM1155 series

NIPPON PRECISION CIRCUITS—4

One-shot (SM1155

×××

3S)

When TG goes HIGH, a single melody play starts. Melody play continues until the melody ends, even if TG

goes open circuit or LOW mid melody. However, if the TG input goes HIGH again during melody play, the

melody play restarts from the beginning.

1 TUNE

Oscillator

OUT

1MΩ

270kΩ

Pull-down resistance

270kΩ

1MΩ

270kΩ

1 TUNE

1MΩ1MΩ

270kΩ270kΩ

From the begining

SM1155 series

NIPPON PRECISION CIRCUITS—5

Power-save Function

As shown in the preceding timing diagrams, the oscillator stops during non-play mode and the pull-down resis-

tance value changes in response to both HIGH-level and LOW-level inputs (power-save pull-down resistor) to

reduce power consumption and extend battery life.

Non-play oscillator stop function

When melody play ends, regardless of the state of TG, the internal oscillator stops and is placed in a standby

state. In this state, the current consumption, including input pin pull-down resistor current (I

max), does not

exceed 3.3µA.

Power-save pull-down resistor

The resistance of the TG input pull-down resistor changes in response to the input voltage. The pull-down

resistance is 500k

Ω

when the input is HIGH, and the pull-down resistance is 135k

Ω

when the input is LOW.

Furthermore, if a light-dependent resistor (CdS) cell is employed as a switch (the pull-down resistance is max-

imum when the CdS resistance is minimum (light) and the pull-down resistance is minimum when the CdS

resistance is maximum (dark)), the combined resistance can be increased, decreasing current consumption.

Musical Speciﬁcations

Maximum program steps

A maximum of 64 steps can be programmed into internal mask-programmable ROM. Each step represents

either a note (sound pitch and length), a rest note, or a jump. The maximum number of jumps is 7.

Note length (including rests)

Eight rhythm values, from sixteenth note to half note, for notes and rests can be programmed, as shown in the

following table.

Also, notes and rests longer than half notes and rests can be created using a tie to connect the notes. This

requires 2 program steps in ROM.

Tempo

The tempo for the standard quarter note can be selected from the following 16 options.

Pitch and scale

The SM1155 series devices support 3.5 octaves ranging from G

to D

, from which 15 notes can be selected to

form a scale.

Type Code

01234567

Note

             

Rest

             

Code

0123456789ABCDEF



= 697 348 232 174 139 116 99.4 87 77.3 69.6 63.3 58 53.5 49.7 46.4 43.5

SM1155 series

NIPPON PRECISION CIRCUITS—6

TYPICAL APPLICATION

The circuits below represent the standard connections for SM1155 series devices.

Circuit 1

Circuit 2

OUT

VDD OUT

TG VSS

Piezoelectric buzzer

OUT

VDD OUT

TG VSS

Piezoelectric buzzer

Circuit 3

OUT

VSS

VDD OUT

Piezoelectric buzzer

Light

SM1155 series

NIPPON PRECISION CIRCUITS—7

NIPPON PRECISION CIRCUITS INC. reserves the right to make changes to the products described in this data sheet in order to

improve the design or perfor mance and to supply the best possible products. Nippon Precision Circuits Inc. assumes no responsibility for

the use of any circuits shown in this data sheet, conveys no license under any patent or other rights, and makes no claim that the circuits

are free from patent infringement. Applications for any devices shown in this data sheet are for illustration only and Nippon Precision

Circuits Inc. m akes no claim or warranty that such applications will be suitable for the use speciﬁed without fur ther testing or modiﬁcation.

The products described in this data sheet are not intended to use for the apparatus which inﬂuence human lives due to the failure or

malfunction of the products. Customers are requested to comply with applicable laws and regulations in effect now and hereinafter,

including compliance with export controls on the distribution or dissemination of the products. Customers shall not export, directly or

indirectly, any products without ﬁrst obtaining required licenses and approvals from appropriate government agencies.

NIPPON PRECISION CIRCUITS INC.

4-3, Fukuzumi 2-chome

Koto-ku, Tokyo 135-8430, Japan

Telephone: 03-3642-6661

Facsimile: 03-3642-6698

NC0011AE 2000.08

NIPPON PRECISION CIRCUITS INC.