Specifications (Continued)

Parameter

Conditions

Min

Max

Units

Notes

Signal Rejection, Frequency Range

-

-

-

-

2

950, 1400, 1800 Level: V

XRANGE = open

-

-40 (7.8 mV)

dBm

-

Hz

XRANGE = V

SS

-

-50 (2.5 mV)

dBm

-

Level: V

XRANGE= open

-

-43 (5.5 mV)

dBm

-

XRANGE= V

SS

-

-53 (1.7 mV)

dBm

-

Duration

-

50

ms

-

-

Outputs

OUT n,

V

OL

I

-

0.5

V

-

STROBE pins

V

OH

I

V

-

V

-

OUT n pins

I

OZ

V

-1

µA-

Inputs

EN, OE,

V

IL

-

-

0.5

V

-

XRANGE, MODE,

V

IH

V

V

-

V

-

PD pins

V

V

-

V

-

Pull-up and

MODE = V

SS

V

12.5

50

µA-

Pull-down currents

V

4

20

µA-

/XRANGE = V

SS

-2

6

µA-

MODE2 = V

DD

V

12.5

100

µA-

V

12.5

25

µA-

PD = V

DD

-4

10

µA-

PD pin

Pull-down current

PD = V

DD

12.5

50

µA-

SIGIN pin

Voltage range

-

-6.5

V

DD

V-

Input impedance

f=500 Hz

80

-

k

Ω

-

Input spectrum

-

-

28

kHz

-

Clock

External clock

V

IL

XOUT open

-

0.2

V

-

connected to XIN V

IH

XOUT open

V

-

V

-

pin

Duty cycle

XOUT open

40

60

%

-

XIN, XOUT with

Capacitance

-

-

10

pF

-

crystal osc. active Internal resistance

-

20

-

M

Ω

-

Power up (t

PD hi to lo

-

30

ms

-

X358 pin

V

OL

C

-

0.2

V

-

I

V

OH

C

V

-

V

-

I

Duty cycle

C

40

60

%

-

Tri-state

t

C

-

250

ns

-

Operation

t

R

-

250

ns

Unless otherwise noted, V

Notes:

1. Per tone.

2. See Table 4 for detection/rejection frequencies.

M-985-01

www.clare.com

3

Rev. 1

Call Progress Tone Detection

Call progress tones are audible tones sent from switch-

ing systems to calling parties to show the status of calls.

Calling parties can identify the success of a call placed

by what is heard after dialing. The type of tone used and

its timing vary from system to system, and though

intended for human ears these signals can provide

valuable information for automated calling systems.

The M-985-01 contains five signal detectors sensitive to

the frequencies often used for these progress tones.

Electronic equipment monitoring the OUTn outputs of

the M-985-01 can determine the nature of signals pres-

ent by measuring their duty cycle. See Mechanical

Dimensions for a diagram of a circuit that could be used

to permit a microcomputer to directly monitor tones on

the telephone line. Much of the character of the

progress tones is in their duty cycle or cadence (some-

times referred to as interruption rate). This information,

coupled with level and frequency indication from the M-

985-01, can be used to decide what progress tones

have been encountered.