NPC SM8230A Datasheet

SM8230A

NIPPON PRECISION CIRCUITS INC.

OVERVIEW

The SM8230A is a dual-tone signal generator LSI
developed for DTMF (dual tone multi-frequency)
dialing. It features a built-in piezo-electric speaker
driver for direct connection to a piezo-electric
buzzer.

The DTMF frequencies can be set to correspond to
the DTMF standards of any country. The output level
is also adjustable under software control. These
features, combined with its small package and low
power dissipation, make the SM8230A a very use
device to use.

FEATURES

■

3-line serial interface to external CPU

■

2 independent, adjustable frequency outputs

■

Piezo driver for direct connection to a piezo­electric buzzer

■

4 system clock frequencies selectable (480 kHz,
960 kHz, 1.92 MHz, 3.84 MHz)

■

2.6 to 3.3 V supply voltage

■

Low current consumption

• 3.0 mA (max) operating current

• 1 µA (max) standby current

■

8-pin plastic SOP

Tone Dialer with Built-in Piezo Driver

PINOUT

8230AS

SD

SCL

OE

VSS

PACKAGE DIMENSIONS

4.4 0.2

6.2 0.3

5.2 0.3

1.27

0.4 0.1

1.5 0.1

0.05 0.05

81

VDD
BZH
BZL
CLK

54

+ 0.10

0.15

− 0.05

010

0.4 0.2

NIPPON PRECISION CIRCUITS—1

BLOCK DIAGRAM

SD

SCL

OE

Programmable

Counter

High Group

SM8230A

ROM

LATCH

SELECTOR

D/A

Converter

Output
Control

VDD
BZH

CLK

VSS

Programmable

Counter

Low Group

ROM

D/A

Converter

PIN DESCRIPTION

Number Name I/O Description

1 SD I Serial data input

2SCLI

3OEI

4 VSS – Ground

5CLKI

6 BZL O DTMF low-frequency group analog output
7 BZH O DTMF high-frequency group analog output
8 VDD – Supply voltage

Serial data transfer clock input.
(For valid transfer, OE must stay LOW for 16 clock cycles.)

DTMF output enable/serial data transfer select input.
Serial data transfer is selected when LOW.

System clock input. The clock can be set to one of four frequencies (480 kHz, 960
kHz, 1.92 MHz, 3.84 MHz).

Output
Control

BZL

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−

−

−

−

°

°

−

° C

−

−

SM8230A

SPECIFICATIONS

Absolute Maximum Ratings

V

= 0 V

SS

Parameter Symbol Rating Unit

Supply voltage range V
Input voltage range V
Output voltage range V
Storage temperature range T
Power dissipation P
Soldering temperature T
Soldering time t

DD

IN

OUT

stg

D

sld

sld

0.3 to 7.0 V

V

0.3 to V

SS

V

0.3 to V

SS

+ 0.3 V

DD

+ 0.3 V

DD

55 to 125

250 mW
255

10 s

C

C

Recommended Operating Conditions

V

= 0 V

SS

Parameter Symbol Condition

Supply voltage range V
Operating temperature T

DD

opr

DC Characteristics

V

= 2.6 to 3.3V, V

DD

Parameter Symbol Condition

Operating current consumption I

Standby current consumption I

Input voltage (all inputs)

Input leakage current I
BZH/BZL tone output voltage V
BZH/BZL tone output adjustment

step
BZH/BZL tone output absolute error D
BZH/BZL tone output impedance Z

= 0 V, T

SS

= − 20 to 70 ° C

a

DD

ST

V

IH

V

IL

IL

BZO

D

RES

LIN

OUT

V

DD

f

CLK

V

DD

HIGH-level input 1.1 – V
LOW-level input V
HIGH/LOW-level input
0 dB output level 0.86V

V

ZBO

Rating

Unit

min typ max

2.6 3.0 3.3 V
20 25 70

Rating

Unit

min typ max

= 3.0 V , T
= 480 kHz

= 25 ° C,

a

– 1.5 3 mA

= 3.3 V, OE = LOW – – 1 µA

DD

SS

– 0.6

1– 1µA

DD

0.93V

DD

1.0V

DD

Vp-p

– 1.0 – dB

levels

1– 1dB

100 150 200

V

Ω

NIPPON PRECISION CIRCUITS—3