CMLMICRO FX643D4

CML Semiconductor Products
Call Progress Tone Detector
FX643
D/643/4 March 1996
1.0
Features
Provisional Issue
•
Worldwide Application
•
Voice Detected
•
Single Tone Decoding
•
Wide Dynamic Signal Range
•
Dual Tone Decoding
•
Low Working Voltage
•
US-Busy Tones Identified
•
Standard 3.58MHz Clock Input
•
Special Information Tones Identified
•
Standard 8-pin DIP and 16-pin
SOIC Packages
1.1
Brief Description
The FX643 decodes the audible tone signals provided by Telecom Systems Worldwide to indicate
Dial, Ringing, Busy, Unobtainable and other stages of a call attempt. Detection of these signals is
essential to applications involving machine dialling or automatic call placement. The FX643 provides
the key features needed for intelligent full-function Call Progress monitoring.
In addition to detecting the full range of standard Call Progress tones, the FX643 adds single and dual
tone decoding for better cross-system Call Progress monitoring. The FX643 also directly identifies the
"US Busy" tones, and the international Special Information Tones, saving the time needed for
"cadence verification" under Busy and Unobtainable conditions. The FX643 will also decode and
indicate speech, or other Non-Call Progress signals: this reduces voice-falsing of Call Progress tones
and adds Voice-Answer as a "connected" prompt.
The FX643 uses new digital signal processing techniques to provide these advantages. It is a low
cost, low power product with superior performance. It is available in industry standard
8-pin and 16-pin packages.
 1996 Consumer Microcircuits Limited
Call Progress Tone Detector
FX643
CONTENTS
Section
Page
1.0 Features......................................................................................................1
1.1 Brief Description ........................................................................................1
1.2 Block Diagram............................................................................................3
1.3 Signal List ..................................................................................................4
1.4 External Components ................................................................................5
1.5 General Description ...................................................................................6
1.5.1 Overall Function Description .........................................................6
1.5.2 Glossary.......................................................................................6
1.5.3 Block Diagram Description............................................................7
1.5.4 Decode Output Truth Table ..........................................................8
1.6 Application Notes ......................................................................................8
1.6.1 General ........................................................................................8
1.7 Performance Specification ........................................................................9
1.7.1 Electrical Performance..................................................................9
1.7.2 Packaging ..................................................................................14
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Call Progress Tone Detector
1.2
FX643
Block Diagram
Note: XTALN for 16-pin SOIC (D4) package only.
Figure 1 Block Diagram
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1.3
FX643
Signal List
Package
D4
Package
P1
Pin No.
Pin No.
Name
Type
2
1
XTAL/CLOCK
I/P
The external clock input to the clock divider
circuit. Also, the input to the on-chip oscillator,
for external Xtal circuit (D4 package only).
3
-
XTALN
O/P
The inverted output of the on-chip oscillator
(D4 package only).
4
2
DETECT3
O/P
When a single tone within the range of the Call
Progress Band or Non Call Progress Band, or a
Special Information Tone, is detected, this
output goes to a logic "1".
5
3
ENABLE
I/P
A logic "0" pulse of at least 1µs applied to this
input resets the decoder circuits and forces
DETECT1, DETECT2 and DETECT3 outputs to
a logic "0".
7
4
DETECT1
O/P
When a call progress signal is detected, this
output goes to a logic "1".
10
5
SIGIN
I/P
Signal input. Signals to this pin should be ac
coupled. The dc bias of this pin is set internally.
12
6
Vss
Power
13
7
DETECT2
O/P
Signal
Description
The negative supply rail (ground).
This output is used in conjunction with
DETECT1.
When DETECT1 is at a logic "1", this output
goes to a logic "1" if a Call Progress High Band
signal is detected.
When DETECT1 is at a logic "0", this output
goes to a logic "1" if a Non Call Progress signal
is detected.
15
8
VDD
1, 6, 8,
9, 11,
14, 16
-
NC
Notes: I/P =
O/P =
Power
The positive supply rail. This pin should be
decoupled to VSS by a capacitor.
Internal connection. Do not make any
connection to these pins.
Input
Output
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1.4
FX643
External Components
Typical Values:
C1
1nF ± 20% at 5V, 560pF ± 20% at 3.3V
C2
0.1µF ± 20%
(For details of clock frequency, refer to Section 1.7.1)
C3, C4 33pF ± 20%
R1
1MΩ ± 10%
X1
3.579545MHz
(Refer to Section 1.7.1)
Figure 2 Recommended External Components
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Call Progress Tone Detector
1.5
General Description
1.5.1
Overall Function Description
FX643
The FX643 Call Progress Tone Detector uses different tone detection methods from those commonly
found with other products.
Many traditional devices use a bandpass filter followed by an energy detector. The filter is usually
designed to pass input signals with a frequency between about 300Hz and 700Hz, and the amplitudes
of signals in this range are then checked against a level threshold. Any signal of acceptable level in
this frequency band is classed as a Call Progress tone, including signals due to speech and noise.
False outputs caused by speech are a common feature with these products, and background noise
may lead to a stuck "detect" output.
The FX643, by contrast, uses a stochastic signal processing technique based on analysis in both the
frequency and time domain, with signal amplitude forming a minor part in the decision process. This
analysis includes checks on whether the signal has a "profile" which matches international standards
for Call Progress tones or Special Information Tones, or a profile more likely to match that of speech,
noise or other non-call-progress signals. It checks on whether the signal is a single tone. It also adds
checks on whether tones which include frequencies corresponding with the "US Busy" signals have
been detected.
The following Glossary, and the Decode Truth Table in section 1.5.4, provide a simple explanation of
the decoding functions and features offered by the FX643.
1.5.2
Glossary
Call Progress Tones: The single and dual frequency tones in the range 350Hz to 620Hz specified
widely for call progress signalling.
Call Progress Band: The nominal range 340Hz to 650Hz within which the FX643 will detect Call
Progress tones. The detection algorithm requires that the tones have the characteristics typical of Call
Progress Tones.
Call Progress Low Band: The nominal range 340Hz to 490Hz. The FX643 will detect single or dual
tones falling entirely within this range as Call Progress Low Band tones.
Call Progress High Band: The nominal range 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 frequencies 950Hz or 1400Hz or 1800Hz.
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 FX643 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.
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FX643
No Signal: A signal falling outside the nominal range 120Hz to 900Hz or Special Information Tone or
the absence of an input signal. Either will be detected as a No Signal condition.
Nominal: Subject to dynamic tolerances within the signal analysis process. Absolute values are not
material or adverse to performance.
1.5.3
Block Diagram Description
(reference Figure 1)
Slicer
The input signal to the slicer is amplified by a self-biased inverting amplifier. The dc bias of this input is
internally set at ½VDD.
Signal Analyser
The frequency range, quality and consistency of the input signal is analysed by this functional block.
The signal to noise ratio must be 16dB or greater. The signal must be consistent over a period of
about 140 ms. These decode criteria are continuously monitored and the assessment is updated
every 7 ms, reference Figure 3.
The analyser samples the call progress signal at 9.3kHz; so care should be taken to avoid high
frequency signals (e.g. 18kHz) aliasing into the call progress band.
Control Logic
This block categorises the nature of the signal into various decoded output states and controls the two
output pins. See the Decode Output Truth Table in section 1.5.4.
Clock
An external clock source is to be connected to the XTAL/CLOCK input pin. Alternatively, the internal
oscillator may be used with an external crystal if the 16-pin SOIC (D4) version of the FX643 is used.
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1.5.4
FX643
Decode Output Truth Table
DETECT3
DETECT2
DETECT1
CONDITIONS
0
0
0
No Signal
1
0
0
Special Information Tone:
Will detect 950, 1400 and 1800Hz tones
0
0
1
Call Progress Low Band:
Will detect 350+440, 400+450 and 440+480Hz tones,
for example
1
0
1
Call Progress Low Band:
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
Non Call Progress signal, e.g. Voice Activity
1
1
0
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.
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1.7
Performance Specification
1.7.1
Electrical Performance
FX643
Absolute Maximum Ratings
Exceeding these maximum ratings can result in damage to the device.
Supply (VDD - VSS)
Voltage on any pin to VSS
Current into or out of VDD and VSS pins
Current into or out of any other pin
P1 and D4 Packages
Total Allowable Power Dissipation at Tamb = 25°C
... Derating
Storage Temperature
Operating Temperature
Min.
-0.3
-0.3
-30
-20
Max.
7.0
VDD + 0.3
+30
+20
Units
V
V
mA
mA
Min.
Max.
800
13
+125
+85
Units
mW
mW/°C
°C
°C
Max.
5.5
3.59
Units
V
MHz
-55
-40
Operating Limits
Correct operation of the device outside these limits is not implied.
Notes
Supply (VDD - VSS)
Xtal Frequency
 1996 Consumer Microcircuits Limited
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Min.
3.0
3.57
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Call Progress Tone Detector
FX643
Operating Characteristics
For the following conditions unless otherwise specified:
Xtal Frequency = 3.579545MHz, S/N = 16 dB, Noise Bandwidth = 5 kHz,
VDD = 3.3V to 5.0V, Tamb = - 40°C to +85°C. 0dB = 775mVrms.
Notes
DC Parameters
IDD (ENABLE = "1")
IDD (ENABLE = "1")
(VDD = 5.0V)
(VDD = 3.3V)
AC Parameters
SIGIN pin
Input Impedance (at 100Hz)
Minimum Input Signal Level
Input Signal Dynamic Range
Signal to Noise Ratio
Clock Input
'High' Pulse Width
'Low' Pulse Width
Input Impedance (at 100Hz)
Gain (I/P = 1mV rms at 100Hz)
Logic Interface
Input Logic "1" Level
Input Logic "0" Level
Input Leakage Current (Vin = 0 to VDD)
Input Capacitance
Output Logic "1" Level (lOH = 120µA)
Output Logic "0" Level (lOL = 360µA)
Notes:
1.
2.
3.
4.
5.
6.
Min.
Typ.
Max.
Units
1
1
0.5
0.3
1.0
0.7
mA
mA
2
3
3
0.35
-40
40
16
MΩ
dB
dB
dB
4
4
40
40
10
20
ns
ns
MΩ
dB
5
5
5
5
6
6
80%
20%
+5.0
5.0
10.0
90%
10%
VDD
VDD
µA
pF
VDD
VDD
Not including any current drawn from the device pins by external circuitry.
Small signal impedance over the frequency range 100Hz to 2000Hz and at 5.0V.
The input level is not critical as the detector uses a stochastic algorithm.
Timing for an external input to the XTAL/CLOCK pin.
ENABLE pin.
DETECT1, DETECT2 and DETECT3 pins.
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1.7.1
FX643
Electrical Performance (continued)
Figure 3 Timing Diagram: Call Progress Tone(s)
Note 1:
DETECT3 is "1" only when the Call Progress Signal, or a Non Call Progress Signal, is a single
frequency tone.
Figure 4 Timing Diagram: Non Call Progress Signal
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1.7.1
FX643
Electrical Performance (continued)
Figure 5 Timing Diagram: Call Progress Tone(s) to Non Call Progress Signal
Note 1:
DETECT3 is "1" only when the Call Progress Signal, or a Non Call Progress Signal, is a single
frequency tone.
Figure 6 Timing Diagram: Special Information Tones
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FX643
For the following conditions unless otherwise specified:
Xtal Frequency = 3.579545MHz, VDD = 3.3V to 5.0V, Tamb = - 40°C to +85°C, S/N = 20dB.
Notes
Min.
Typ.
Max.
Units
70
ms
Signal Timings (ref. Figures 3, 4, 5 and 6)
tI
Burst Length Ignored
10
tL
Burst Length Detected
10
tGI
Call Progress Tone Gap Length Ignored
tGD
Call Progress Tone Gap Length Detected
tRP
Call Progress Tone Response Time
10
145
ms
tDRP
Call Progress Tone De-response Time
10
145
ms
tGDR
Gap Detected Recorded
tNG
Non Call Progress Signal Gap Length Ignored
tNRP
Non Call Progress Signal Response Time
tNDRP
Non Call Progress signal De-response Time
tCH
State Change
Notes:
7.
8.
9.
10.
11.
145
ms
7,10,11
7,10
8,10
20
40
ms
6
9
ms
80
145
ms
ms
80
0
ms
ms
ms
Only applies to bursts of the same frequency.
To acknowledge a short tone gap ≥ 40 ms, No Signal is indicated for a minimum of 6ms.
If the gap > 90 ms, a No Signal state will be decoded.
Timings also apply to Special Information Tone.
Special Information Tone Gap Length Ignored is 15ms maximum.
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Call Progress Tone Detector
1.7.2
FX643
Packaging
Figure 7 P1 Mechanical Outline: Order as part no. FX643P1
Figure 8 D4 Mechanical Outline: Order as part no. FX643D4
Handling precautions: This product includes input protection, however, precautions should be taken to prevent
device damage from electro-static discharge. CML does not assume any responsibility for the use of any circuitry
described. No IPR or circuit patent licences are implied. CML reserves the right at any time without notice to
change the said circuitry and this product specification. CML has a policy of testing every product shipped using
calibrated test equipment to ensure compliance with this product specification. Specific testing of all circuit
parameters is not necessarily performed.
CONSUMER MICROCIRCUITS LIMITED
1 WHEATON ROAD
WITHAM - ESSEX CM8 3TD - ENGLAND
Telephone:
Telefax:
+44 1376 513833
+44 1376 518247