MX COM Inc MX612E3, MX612P6 Datasheet

COMMUNICATION ICs

DATA BULLETIN

CMX612

Calling Line Identifier

with VMWI

¤1999 MX-COM, Inc. www.mxcom.com tel: [phone] 744 5050 fax: [phone] Doc. # 20480202.002

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

ADVANCE INFORMATION

Features Applications

x

CLI, CIDCW and VMWI System Operation

x

CLASS (FSK) and SDT (Stuttered Dial Tone)

x

Low Power Operation 0.5mA at 2.7V

x

Zero-Power Detector for Ring or Line

Reversal

x

Low CAS Tone Falsing in CIDCW Mode

x

Bellcore, British Telecom, ETSI, and

Mercury Compatible

x

CLI and CIDCW Adjunct Boxes

x

CLI and CIDCW Feature Phones

x

Computer Telephony Integration

x

Call Logging Systems

x

Voice-Mail Equipment

-

+

XTAL

XTAL

­+

Bandpass

Filters

FSK

Demod

Level

Detector

Detect

Mode

Tone Alert

Detector

Dial Tone

Detector

Data

Retiming

Mode

Control

Logic

RXD

RXCLK

IRQ

IN1-

IN2-

IN1+

IN2+

AMPOUT1

AMPOUT2

Power

Supply

Circuits

Xtal Osc and

Clock Dividers

DET

RD

RT

V

DD

V

BIAS

V

SS

MODE 2

MODE 1

INPUT SELECT

The CMX612 is a low power CMOS device used for the reception of physical layer signals in Bellcore’s
Calling Identity Delivery system (CID), British Telecom’s Calling Line Identification Service (CLIP), the Cable
Communications Association’s Caller Display Services (CDS), and similar evolving systems. This device also
meets the requirements of emerging Caller Identity with Call Waiting Services (CIDCW).

Visual Message Waiting Indicator (VMWI) detection in both CLASS (FSK) and (SDT) Stuttered Dial Tone
modes is provided by the CMX612. In addition, two different signal inputs are available to support Tip/Ring
and Hybrid connectivity. This device includes a ‘zero-power’ ring or line reversal detector, two dual-tone
detectors and a 1200-baud FSK Bell 202/V.23 compatible asynchronous data demodulator. The dual-tone
detectors are the Tone Alert Signal (2130Hz plus 2750Hz) detector and the stuttered dial tone (350Hz plus
440Hz) detector. The 1200-baud FSK Bell 202/V.23 compatible asynchronous data demodulator with data
retiming circuitry removes the need for a UART in the associated

P

C.

The CMX612 is suitable for use in systems using Bellcore specifications GR-30-CORE and SR-TSV-002476,
British Telecom specifications SIN227 and SIN242, CCA TW/P&E/312, ETSI ETS 300 659 parts 1 and 2, ETS
300 778 parts 1 and 2, and Mercury Communications MNR 19.

This device may be used with a 2.7V to 5.5V power supply and is available in the following packages:
20-pin TSSOP (CMX612E3) or 22-pin PDIP (CMX612P6).

Calling Line Identifier with VMWI 2 CMX612 Advance Information

¤1999 MX-COM, Inc. www.mxcom.com tel: [phone] 744 5050 fax: [phone] Doc. # 20480202.002

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

CONTENTS

Section Page

1 Block Diagram................................................................................................................3

2 Signal List.......................................................................................................................4

3 External Components....................................................................................................5

4 General Description.......................................................................................................6

4.1 Mode Control Logic ............................................................................................................. 6

4.2 Input Signal Amplifiers......................................................................................................... 7

4.3 Bandpass Filters.................................................................................................................. 8

4.4 Level Detector ..................................................................................................................... 8

4.5 FSK Demodulator................................................................................................................ 8

4.6 FSK Data Retiming.............................................................................................................. 9

4.7 Tone Alert Detector ........................................................................................................... 10

4.8 Dial Tone Detector............................................................................................................. 11

4.9 Ring or Line Polarity Reversal Detector ............................................................................ 11

4.10 Xtal Osc and Clock Dividers.............................................................................................. 12

5 Application Notes ........................................................................................................13

5.1 'On-Hook' Operation..........................................................................................................13

5.1.1 Bellcore System ...................................................................................................................13

5.1.2 British Telecom System........................................................................................................13

5.1.3 Other On-hook Systems.......................................................................................................14

5.2 'Off-Hook' Operation.......................................................................................................... 16

5.3 VMWI Operation................................................................................................................ 18

5.3.1 SDT Mode............................................................................................................................18

5.3.2 CLASS (FSK) Mode.............................................................................................................18

6 Performance Specification..........................................................................................20

6.1 Electrical Performance ...................................................................................................... 20

6.1.1 Absolute Maximum Ratings..................................................................................................20

6.1.2 Operating Limits...................................................................................................................20

6.1.3 Operating Characteristics.....................................................................................................21

6.2 Packaging.......................................................................................................................... 24

MX-COM, Inc. reserves the right to change specifications at anytime and without notice.

Calling Line Identifier with VMWI 3 CMX612 Advance Information

¤1999 MX-COM, Inc. www.mxcom.com tel: [phone] 744 5050 fax: [phone] Doc. # 20480202.002

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

1 Block Diagram

-

+

XTAL

XTAL

-

+

Bandpass

Filters

FSK

Demod

Level

Detector

Detect

Mode

Tone Alert

Detector

Dial T one

Detector

Data

Retiming

Mode

Control

Logic

RXD

To / From µC

RXCLK

IRQ

IN1-

IN2-

IN1+

IN2+

AMPOUT1

Tip & Ring

Hybrid

Rx Output

AMPOUT2

C8

C9

R5

C5

C2

C1

X1

Power

Supply

Circuits

Xtal Osc and

Clock Dividers

DET

RD

RT

V

DD

V

BIAS

V

SS

V

DD

3.579545MHz

MODE 2

MODE 1

INPUT SELECT

Figure 1: Block Diagram

Calling Line Identifier with VMWI 4 CMX612 Advance Information

¤1999 MX-COM, Inc. www.mxcom.com tel: [phone] 744 5050 fax: [phone] Doc. # 20480202.002

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

2 Signal List

Package Signal

E3 P6 Name Type

Description

11

XTAL

output The output of the on-chip Xtal oscillator inverter.

2 2 XTAL input The input to the on-chip Xtal oscillator inverter.
3 3 RD input (S) Input to the Ring or Line Polarity Reversal Detector.
4 4 RT bi-directional Open-drain output and Schmitt trigger input forming part of the

Ring or Line Polarity Reversal detector. An external resistor
to V

DD

and a capacitor to VSS should be connected to RT to

filter and extend the RD input signal.

55 INPUT

SELECT

input (S) Controls the selection of the two Input Signal Amplifiers. A

low level selects Input 1 and a high level selects Input 2.

6 6 AMPOUT1 bi-directional The output of on-chip Input Signal Amplifier 1 and an input to

the signal selection multiplexer.
7 7 IN1- input The inverting input to on-chip Input Signal Amplifier 1.
8 8 IN1+ input The non-inverting input to on-chip Input Signal Amplifier 1.
910 V

BIAS

output Internally generated bias voltage, held at VDD/2 when the

device is not in ‘Zero-Power’ mode. Should be bypassed to

V

SS

by a capacitor mounted close to the device pins.

10 11 V

SS

Power Negative supply rail (signal ground).
11 12 IN2+ input The non-inverting input to on-chip Input Signal Amplifier 2.
12 13 IN2- input The inverting input to on-chip Input Signal Amplifier 2.
13 14 AMPOUT2 bi-directional

The output of on-chip Input Signal Amplifier 2 and an input to

the signal selection multiplexer.
14 15 MODE 2 input (S) Input used to select the operating mode. See Section 4.1.
15 16 MODE 1 input (S) As per MODE 2 description.
16 17

IRQ

output An open-drain active low output that may be used as an

Interrupt Request/Wake-up input to the associated PC. An

external pull-up resistor should be connected between this

output and V

DD

.

17 18 DET output

A logic level output driven by the Ring or Line Polarity

Reversal Detector, the Tone Alert Detector, the Dial Tone

Detector or the FSK Level detect circuits, depending on the

operating mode. See Section 4.1.
18 19 RXCLK input (S)

An input that may be used to clock received data bits out of

the FSK Data Retiming block.
19 21 RXD output A logic level output carrying either the raw output of the FSK

Demodulator or re-timed 8-bit characters depending on the

state of the RXCLK input. See Section 4.6
20 22 V

DD

Power The positive supply rail. Levels and thresholds within the

device are proportional to this voltage. Should be bypassed

to V

SS

by a capacitor mounted close to the device pins.

9, 20 Not used. Do not connect to these pins.

Input (S) = Schmitt Trigger Input

Table 1: Signal List

Calling Line Identifier with VMWI 5 CMX612 Advance Information

¤1999 MX-COM, Inc. www.mxcom.com tel: [phone] 744 5050 fax: [phone] Doc. # 20480202.002

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

3 External Components

Tip & Ring

20
19
18
17
16
15

10

13
12
11

14

1
2
3
4
5
6
7
8
9

XTAL
XTAL

V

DD

V

SS

V

BIAS

V

BIAS

V

BIAS

IN1+

IN2+

INPUT SELECT

IN1-

IN2-

RD

RT

RXD
RXCLK
DET
IRQ
MODE 1
MODE 2

X1

R1

R2

R3

R4

R5

R8

R6

R7

R9 R10

R13

R12

R11

R17

R16

1:1

2-Wire

Line

R15

R14

R18

D1 - 4

C3

C2

C1

C4

C5

C6

C7

C14

RELAY DRIVER

LOUDSPEAKER

MIC

C13 C12

C11

C8

C9

V

DD

V

DD

V

DD

To/From µC

From µC

Line

Protection

Network

A

B

CMX

612

AMPOUT1

AMPOUT2

Figure 2: Recommended External Components Typical Application

R1

470k

:

C1, C2 18pF

R2 See Section 4.8 C3, C4

0.1PF

R3 – R7

470k

:

C5

0.33PF

R8 Note 1

470k: for V

DD

= 3.3V

680k: for V

DD

= 5.0V

C6, C7 680pF

R9 Note 1

240k: for V

DD

= 3.3V

200k: for V

DD

= 5.0V

C8, C9 Note 2

0.1PF

R10

160k

:

C11, C12 330pF

R11 - R14

100k

:

C13 10nF

R15

600

:

C14 100nF

R16

120k

:

R17

100k

:

X1 Note 3 3.579545MHz

R18

100k: r20%

D1 - D4 1N4004

Resistors r1%, capacitors r20% unless otherwise stated.

Table 2: Recommended External Components for Typical Application

Calling Line Identifier with VMWI 6 CMX612 Advance Information

¤1999 MX-COM, Inc. www.mxcom.com tel: [phone] 744 5050 fax: [phone] Doc. # 20480202.002

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

Recommended External Components Notes:

1. Reference Section 4.2

2. It is recommended that the printed circuit board be laid out with a ground plane in the CMX612 area to
provide a low impedance ground connection to the V

SS

pin and to the decoupling capacitors C8 and C9.

3. For best results, a crystal oscillator design should drive the clock inverter input with signal levels of at
least 40% of V

DD

, peak to peak. Tuning fork crystals generally cannot meet this requirement. To obtain

crystal oscillator design assistance, please consult you crystal manufacturer.

4 General Description

4.1 Mode Control Logic

The CMX612's operating mode and the source of the DET and

IRQ

outputs are determined by the logic levels

applied to the MODE 1 and MODE 2 input pins;

MODE 1 MODE 2 Mode DET output from

IRQ

output from

0 0 Tone Alert Detect Tone Alert Signal Detection.

CAS tones present.

Valid ‘off-hook’ CAS or
Ring or Line Polarity

Reversal Detection.
Ringing Signal present.

0 1 FSK Receive FSK Level Detection.

FSK present.

FSK Data Retiming [1] or
Ring or Line Polarity

Reversal Detection.
Ringing Signal present.

1 0 'Zero-Power' Ring or Line Polarity Reversal

Detection.
Ringing Signal present.

Ring or Line Polarity
Reversal Detection.

Ringing Signal present.

1 1 Dial Tone Detect Dial Tone Signal Detection.

Both tones present.

Valid dial tone detected.

[1]

If enabled.

In 'Zero-Power' mode, power is removed from all of the internal circuitry except for the Ring or Line Polarity
Reversal Detector and the DET and

IRQ

outputs.

Calling Line Identifier with VMWI 7 CMX612 Advance Information

¤1999 MX-COM, Inc. www.mxcom.com tel: [phone] 744 5050 fax: [phone] Doc. # 20480202.002

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

4.2 Input Signal Amplifiers

These amplifiers can be used to convert the balanced FSK, Tone Alert and VMWI signals received over the
telephone line to an unbalanced signal of the correct amplitude for the FSK receiver, Tone Alert and Dial
Tone Detector circuits.

-

+

V

SS

V

BIAS

AMPOUT

IN+

IN-

R8R6

R7

R9 R10

C6

C7

C9

A
B

Input Signal Amplifier

Figure 3: Input Signal Amplifier, balanced input configuration

The design equations for this circuit are;

()

10R-8R

10R

×8R=9R

k160=R10

k470=7R=6R

R9

R8

=

)A-B(V

V

g

ain voltage alDifferenti

AMPOUT

c

c

The target differential voltage gain depends on the expected signal levels between the A and B wires and the
CMX612's internal threshold levels, which are proportional to the supply voltage.

The CMX612 has been designed to meet the applicable specifications with R8 = 430k: at V

DD

= 3.0V

nominal, rising to 680k: at V

DD

= 5.0V, and R9 should be 240k: at V

DD

= 3.0V and 200k: at V

DD

= 5.0V as

shown in Section 3 and Figure 5.
The Input Signal Amplifiers may also be used with an unbalanced signal source as shown in Figure 4. The

values of R6 and R8 are as for the balanced input case.

-

+

V

SS

V

BIAS

AMPOUT

IN+

IN-

R8R6

C6

C9

A

Input Signal Amplifier

Figure 4: Input Signal Amplifier, unbalanced input configuration

Calling Line Identifier with VMWI 8 CMX612 Advance Information

¤1999 MX-COM, Inc. www.mxcom.com tel: [phone] 744 5050 fax: [phone] Doc. # 20480202.002

4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

0

100

200

300

400

500

600

700

800

900

1000

33.544.55
Nominal V (V)

DD

R8

R9

R8 and R9 : k W

Figure 5: Input Signal Amplifier, optimum values of R8 and R9 vs. V

DD

4.3 Bandpass Filters

These are used to attenuate out of band noise and interfering signals which might otherwise reach the FSK
Demodulator, Tone Alert Detector, Dial Tone detector and Level Detector circuits. The characteristics of
these filters differ in FSK, Tone Alert and Dial Tone modes. Most of the filtering is provided by switched
capacitor stages clocked at 57.7kHz or 9.62kHz depending on mode of operation.

4.4 Level Detector

This block operates by measuring the level of the signal at the output of the Bandpass Filter, and comparing it
against a threshold that depends on whether FSK Receive, Tone Alert Detect or Dial Tone Detect mode has
been selected.

In Tone Alert Detect mode, the output of the Level Detector block provides an input to the Tone Alert Signal
Detector.

In Dial Tone Detect mode, the output of the Level Detector block provides an input to the Dial Tone Signal
Detector.

In FSK Receive mode, the CMX612 DET output will be set high when the level has exceeded the threshold
for sufficient time. Amplitude and time hysteresis are used to reduce chattering of the DET output in marginal
conditions.

Note that in FSK Receive mode this circuit may also respond to non-FSK signals such as speech.

DET

Line Signal

MODE 1
MODE 2

FSK Receiver mode

FSK signal

t

EON

t

EOFF

See Section 6.1 for definitions of t

EON

and t

EOFF

Figure 6: FSK Level Detector Operation

4.5 FSK Demodulator

This FSK Demodulator block converts the 1200 baud FSK input signal to a logic level received data signal
which is output via the RXD pin as long as the Data Retiming function is not enabled (see Section 4.6). This
output does not depend on the state of the FSK Level Detector output.

N

ote:

In the absence of a valid FSK signal, the demodulator may falsely interpret speech or other extraneous

signals as data.