1

Features

Features

Features

Features

Features

Detects 12kHz and 16kHz SPM

Detects 12kHz and 16kHz SPM

Detects 12kHz and 16kHz SPM

Detects 12kHz and 16kHz SPM

Detects 12kHz and 16kHz SPM

Frequencies

Frequencies

Frequencies

Frequencies

Frequencies

Lo

Lo

Lo

Lo

Low P

w P

w P

w P

w Po

o

o

o

ower (3.0

wer (3.0

wer (3.0

wer (3.0

wer (3.0 V

V

V

V

Volt

olt

olt

olt

olt

MIN

MIN

MIN

MIN

<1.0mA)

<1.0mA)

<1.0mA)

<1.0mA)

Operation

Operation

Operation

Operation

Operation

High Speec

High Speec

High Speec

High Speec

High Speechband Rejection

hband Rejection

hband Rejection

hband Rejection

hband Rejection

Pr

Pr

Pr

Pr

Proper

oper

oper

oper

operties

ties

ties

ties

ties

PRODUCT INFORMATION

PRODUCT INFORMATION

PRODUCT INFORMATION

PRODUCT INFORMATION

PRODUCT INFORMATION

Fig.1 Functional Block Diagram

FX631

FX631

FX631

FX631

Lo

Lo

Lo

Low-V

w-V

w-V

w-V

w-Volta

olta

olta

olta

oltag

g

g

g

ge SPM Detector

e SPM Detector

e SPM Detector

e SPM Detector

e SPM Detector

T

T

T

T

Tone-Follo

one-Follo

one-Follo

one-Follo

one-Follower and P

wer and P

wer and P

wer and P

wer and Pac

ac

ac

ac

acket Mode

ket Mode

ket Mode

ket Mode

ket Mode

Outputs

Outputs

Outputs

Outputs

Outputs

Applications

Applications

Applications

Applications

Applications

Comple

Comple

Comple

Comple

Complex and/or Simple

x and/or Simple

x and/or Simple

x and/or Simple

x and/or Simple

T

T

T

T

Telephone Systems

elephone Systems

elephone Systems

elephone Systems

elephone Systems

Call-Char

Call-Char

Call-Char

Call-Char

Call-Charg

g

g

g

ge/-Log

e/-Log

e/-Log

e/-Log

e/-Logging

ging

ging

ging

ging

Systems

Systems

Systems

Systems

Systems

1

32

PERIOD

MEASURE

TONE

FOLLOWER

LOGIC

PACKET

TONE

LOGIC

DIVIDER

SIGNAL

IN (-)

AMP OUT

XTAL/CLOCK

(12kHz/16kHz)

SYSTEM

SYSTEM

SYSTEM

CLOCK IN

CLOCK

OUT

TONE FOLLOWER

OUTPUT

PACKET MODE

OUTPUT

SIGNAL

IN (+)

LEVEL DETECTOR

+20dB

12kHz/16kHz

XTAL

CLOCK

DIVIDERS

INPUT AMP

XTAL/CLOCK

OSCILLATOR

Brief Description

Brief Description

Brief Description

Brief Description

Brief Description

The FX631 is a low-power, system-selectable

Subscriber Pulse Metering (SPM) detector to indicate

the presence, on a telephone line, of both 12kHz and

16kHz telephone call-charge frequencies.

Deriving its input directly from the telephone line,

input amplitude/sensitivities are component adjustable to

the user's national ‘Must/Must-Not Decode’

specifications via an on-chip input amplifier, whilst the

12kHz and 16kHz frequency limits are accurately

defined by the use of an external 3.579545MHz

telephone-system Xtal or clock-pulse input.

The FX631, which demonstrates high 12kHz and

16kHz performance in the presence of both voice and

noise, can operate from either a single or differential

analogue signal input from which it will produce two

individual logic outputs.

1. Tone Follower Output - A 'tone-following' logic

output producing a “Low” level for the period of a

correct decode and a “High” level for a bad

2. Packet (Cumulative Tone) Mode Output - To

respond and de-respond after a cumulative 40ms

This process will ignore small fluctuations or

fades of a valid frequency input and is available

for µProcessor ‘Wake-Up’, Minimum tone

avoidance.

This system (12kHz/16kHz) selectable microcircuit,

which may be line-powered, is available in 16-pin plastic

DIL and surface mount SOIC and 24-pin plastic SSOP

packages.

CML Semiconductor Products

CML Semiconductor Products

CML Semiconductor Products

CML Semiconductor Products

CML Semiconductor Products

FX631

FX631

FX631

FX631

FX631

Publication D/631/8 July 1998