OKI MSA180RS, MSA180MS-K Datasheet

E2D0049-39-21

¡ Semiconductor

This version: Feb. 1999

Previous version: May. 1997

MSA180¡ Semiconductor

MSA180

Piezo Speaker Amplifier

GENERAL DESCRIPTION

The MSA180 is a piezo speaker driver for OKI's speech synthesizers. Its voltage gain can be adjusted by a factor of up to 10. The differential output provides an amplitude of twice the voltage supply. A separate output connects to the base of an external transistor for controlling system voltage. A standby function eliminates power loss when no input signal is present.

FEATURES

• Power supply voltage : 2.0 V to 6.0 V (single supply voltage)

• Low current consumption : 4.2 mA typ (VCC=3 V, no load)

• Standby current : <1 mA

• Differential output : Twice the supply voltage (maximum output amplitube)

• Package options : 8-pin plastic DIP (DIP8-P-300-2.54) (Product name: MSA180RS) 8-pin plastic SOP (SOP8-P-250-1.27-K) (Product name: MSA180MS-K) Chip

BLOCK DIAGRAM

V

CC

MODE1 MODE2

A

IN

GND

Logic

18 kW

CC

V

CC

2.2 kW

+

AV=20

–

1.3 kW

+

=20

A

V

–

6.6 kW6.6 kW

V

BASE

SP

1/16

PIN CONFIGURATION (TOP VIEW)

MSA180¡ Semiconductor

MODE2

A

GND

SP

1

2

IN

3

4

8

7

6

5

MODE1

BASE

V

CC

SP

8-Pin Plastic DIP or 8-Pin Plastic SOP

PIN DESCRIPTIONS

Pin Type Description

6V 3 GND — Ground pin. 2A

8 MODE1 I

1 MODE2 I

7 BASE O

4 SP O

5SPO

Symbol

CC

IN

— Power supply pin.

I Voice signal input pin.

This pin switches the device between operation and standby modes. The IC is in operation mode if V standby mode if V

IL

MODE2 must be connected to V This pin switches the device between operation and standby modes. The IC is in operation mode if V standby mode if V

IH

MODE1 must be connected to GND. This pin is connected to the base of an external transistor. If an external transistor is not used to control system voltage, this pin must be left open. This is a speaker output pin that provides signals with the same phase as the input. This is a speaker output pin that provides signals with an inverted phase to the input.

< 0.3 V on the MODE1 pin. When MODE1 is used,

> VCC–0.3 V on MODE1 pin. When MODE2 is used

> 1.0 V on the MODE1 pin and is in

IH

.

CC

< VCC–1.0 V on MODE1 pin and is in

IL

2/16

ABSOLUTE MAXIMUM RATINGS

Parameter Symbol Condition Rating Unit Remarks

Power Supply Voltage V

Input Voltage V

Maximum Output Current I

OMAX

Power Dissipation P

Junction Temperature T Storage Temperature T

CC

IN

D

jMAX

STG

— –0.3 to +6.5 V —

— –0.3 to VCC+0.3 V

VCC=3 V ±80 mA SP, SP

Ta=25°C

— 110 °C Chip — –55 to +150 °C —

RECOMMENDED OPERATING CONDITIONS

MSA180¡ Semiconductor

(Ta=25°C unless otherwise specified)

A

IN

MODE1 MODE2

BASE

400 mW DIP type 340 mW SOP type

Parameter Symbol Min. Max. UnitCondition

Power Supply Voltage V Load Impedance Z Peak Load Current I

V

"H" Input Voltage

V

"L" Input Voltage

V

Operating Temperature T

CC

O-P

IH1

IH2

IL1

IL2

op

L

Applied to MODE1 pin Applied to MODE2 pin Applied to MODE1 pin Applied to MODE2 pin

2.0 6.0 V—

200 — W—

— ±30 mA—

1.0 — V

VCC–0.3 — V

— 0.3 V —V

–1.0 V

CC

–40 +85 °C—

3/16

ELECTRICAL CHARACTERISTICS

Parameter Symbol Condition Min. Typ. Max. Unit

A

V1

Voltage Gain

AIN Input Resistance R

Output DC Voltage

Output DC Offset Voltage

*1

*2

SP, SP Output "H" Voltage V SP, SP Output "L" Voltage V

Operating Current I

Circuit Current in Standby Mode I

AIN Input DC Bias Voltage V

*3

MODE1 "H" Input Current I MODE2 "H" Input Current I MODE1 "L" Input Current I MODE2 "L" Input Current I

Base Output Current

A A

V

DV

CCS

IH1

IH2

IL1

IL2

I

BO1

I

BO2

V2

V3

IN

O

OH

OL

CC

AIN

(Ta=25°C, V

=2 V to 6 V unless otherwise specified)

CC

AINÆSP 4.25 5 5.75 V/V AINÆSP 4.25 5 5.75 V/V

AINÆ(SP-SP) 8.5 10 11.5 V/V

— 17.2 24.6 32.0 kW

=2 V 0.7 1.0 1.3 V

V

No signal

SP-SP

I

OUT

I

OUT

CC

=6 V 2.5 3.5 4.6 V

V

CC

V

=2 V — — 0.2 V

CC

=6 V — — 0.6 V

V

CC

=–10 mA VCC–0.25 — — V

=10 mA — — 0.25 V

=3 V

V

CC

Z

=•

L

BASE=Open

— 4.2 6.2 mA

MODE1=MODE2=GND

or

MODE1=MODE2=V

CC

AIN=Open

—— 1 µAMODE1=GND

MODE2=V

CC

VCC=2 V 0.18 0.26 0.34 V

=6 V 0.52 0.74 0.96 V

V

CC

MODE1=V MODE2=V

CC

— — 160 µA

—— 1 µA MODE1=GND –1 — — µA MODE2=GND –160 — — µA

VCC=2 V

0.4 — — mA

BASE=V

CC

VCC=6 V

1.6 — — mA

BASE=V

CC

MSA180¡ Semiconductor

*1 Typical value is VO = V

CC

*2 Maximum value is DVO = V *3 Typical value is V

AIN

= V

CC

¥ 0.625 – 0.25.

¥ 0.1.

CC

¥ 0.12 + 0.02.

4/16

MSA180¡ Semiconductor

APPLICATION CIRCUITS

How to Adjust Gain

Gain control adjustment of the input signal level is shown below. When using OKI's speech synthesizer devices, insert a diode in series with the variable resistor to reduce pop noise.

V

DD

Signal

R1

100 kW

C1

0.1 mF

BASE

MODE2

A

IN

MODE1

V

MSA180

CC

PIEZO SPEAKER

SP

GND

The circuit below also implements gain adjustment for a higher impedance signal source.

V

DD

Signal

R1

20 kW

C1

0.1 mF

BASE

MODE2

A

IN

MODE1

V

MSA180

GND

CC

PIEZO SPEAKER

SP

5/16

MSA180¡ Semiconductor

How to Connect the Piezo Speaker

To achieve the full gain level of 10 V, even at a low supply voltage (VCC=3 V), connect a coil in series with the piezo speaker.

V

DD

BASE

MODE2

A

IN

MODE1

V

MSA180

CC

SP

COIL

PIEZO SPEAKER

GND

The resonance frequency that occurs in the circuit containing the coil and the piezo speaker is :

fQ =

2p C

1

L

¥ L

[Hz]

L

Where CL is the piezo capacitance and LL the coil inductance. For instance, if the piezo capacitance is 0.1 mF and fQ is in a range of 2 to 3 kHz, then the coil inductance should be 30 mH.

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