Call Progress Tone Detector

MX643 - Preliminary Information

© 1996 MX•COM, INC.

Tele: 800 638 5577, 910 744 5050, Fax: 910 744 5054

Doc. #20480148.001

5

3. External Components

CLOCK

C2

8

7

2

3

4

5

6

DETECT1

MX643P

ENABLE

SIGIN

DETECT2

DETECT3

C1

1

XTAL/

CLOCK

C3

C2

R1

X1

C4

DETECT3

MX643DW

ENABLE

SIGIN

DETECT2

C1

XTAL

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

DETECT1

N/C

N/C

N/C

N/C

N/C

N/C

N/C

MX643P

C1

1.0nF

±20

R1

1M

Ω±10

C2

1.0

µF

±20

C1

560pF at 3.3VDD

1.0nF at 5.0VDD

±20

For details of CLOCK frequency refer to Sec.6.1

C2

1.0

µF

±20

C3

33pF

±20

C4

33pF

±20

X1

3.579545MHz

refer to Sec. 6.1

Figure 2: Recommended External Components for Typical Applications

4. General Description

4.1 Glossary

The following glossary and Decode Truth table (found in section 5.1), describe the MX643 decoding features and

functions.

Call Progress Tones: The single and dual frequency tones in the range of 350Hz to 620Hz specified widely for

Call Progress signaling.

Call Progress Band: The nominal range is 340Hz to 650Hz within which the MX643 will detect Call Progress

tones. The detection algorithm requires that the tones have characteristics typical of Call Progress Tones.

Call Progress Low Band: The nominal range is 340Hz to 490Hz. The MX643 will detect single or dual tones

falling entirely within this range, as Call Progress Low Band tones.

Call Progress High Band: The nominal range is 600Hz to 650Hz. Single tones in this range, or dual tones

having a material frequency component within this range (e.g. 480 + 620Hz), are detected as Call Progress High

Band tones.

Special Information Tone: The nominal range is 950Hz or 1400Hz or 1800Hz, with a tolerance of

±50Hz.

Non Call Progress Signal: A signal falling within the nominal range (a) 200Hz to 800Hz, but NOT within the Call

Progress Band, or (b) within the nominal range 200Hz to 800Hz, but NOT meeting the DETECTION

REQUIREMENTS when the signal falls in the Call Progress Band.

Subject to the duration and other characteristics of such signals, the MX643 will usually interpret these as a Non

Call Progress Signal (e.g. speech or other signal activity).

Minimum Input Signal: The minimum signal level for the specified tone decoding performance. The lower level

at which absence of an input signal will be registered is not specified.

No Signal: A signal falling outside the nominal range of 120Hz to 900Hz or Special Information Tone or the

absence of an input signal. Either will be detected as a No Signal condition.