FX643 Datasheet, PDF (8/14 Pages) CML Microcircuits – Call Progress Tone Detector

Call Progress Tone Detector
1.5.4 Decode Output Truth Table
FX643
DETECT3 DETECT2 DETECT1
CONDITIONS
0
0
0
No Signal
1
0
0
Special Information Tone:
Will detect 950, 1400 and 1800Hz tones
Call Progress Low Band:
0
0
1
Will detect 350+440, 400+450 and 440+480Hz tones,
for example
Call Progress Low Band:
1
0
1
Will detect single 400, 425, 440, and 450Hz tones,
for example
0
1
1
Call Progress High Band:
Will detect 480+620Hz tones, for example
1
1
1
Call Progress High Band:
Will detect single 600 and 620Hz tones, for example
0
1
0
1
1
0
Non Call Progress signal, e.g. Voice Activity
Will detect a single tone lying outside the
Call Progress Band and within the Non Call
Progress signal range
Note that: DETECT1 responds to the whole range of call progress signals from 340Hz to 650Hz
DETECT2 responds to higher frequency call progress signals and voice or similar activity
DETECT3 responds to and indicates the presence of a single tone
1.6 Application Notes
1.6.1 General
On power-up, a logic "0" at the ENABLE input may be used to disable and initialise the device.
© 1996 Consumer Microcircuits Limited
8
D/643/4