CPC5611A Просмотр технического описания (PDF) - Clare Inc => IXYS

Номер в каталоге

Компоненты Описание

производитель

CPC5611A

LITELINK™ II Silicon Data Access Arrangement (DAA) IC

Clare Inc => IXYS 

typical operation. The ring detection threshold can be

changed according to the following formula:

VRINGPK

=





7---5---R0----m3-----V--

(2R6 + R3)2 + (---π----f-R----I--N-1--G----C----7---)--2-

Clare Application Note AN-117 Customize Caller ID Gain

and Ring Detect Voltage Threshold is a spreadsheet for

trying different component values in this circuit.

Changing the ring detection threshold will also change

the caller ID gain and the timing of the polarity reversal

detection pulse, if used.

3.2.2 Polarity Reversal Detection with

CPC5611

The full-wave ring detector in the CPC5611 makes it

possible to detect tip and ring polarity reversal using

the RING output. When the polarity of tip and ring

reverses, a pulse on RING indicates the event. Your

host system must be able to discriminate this single

pulse of approximately 1 msec (using the recom-

mended snoop circuit external components) from a

valid ringing signal.

3.2.3 On-hook Caller ID Signal Processing

On-hook caller ID (CID) signals are processed by

LITELINK by coupling the CID data burst through the

snoop circuit to the LITELINK RX outputs under con-

trol of the CID pin. In North America, CID data signals

are typically sent between the first and second ringing

signal.

Figure 5. On-hook Caller ID Signal Timing in

North America for CPC5610 (with Half-

wave Ring Detect)

2s 500 ms

3s

475 ms 2s

RING First Ring

Caller ID data

Second Ring

CID

Signal levels not to scale

CPC5610/CPC5611

In North American applications, follow these steps to

receive on-hook caller ID data via the LITELINK RX

outputs:

1. Detect the first ringing signal outputs on RING.

2. Assert CID low.

3. Process the CID data from the RX outputs.

4. De-assert CID (high or floating).

Note: Taking LITELINK off-hook (via the OH pin) dis-

connects the snoop path from both the receive outputs

and the RING output, regardless of the state of the

CID pin.

CID gain from tip and ring to RX+ and RX- is deter-

mined by:

GAINCID(dB) = 20log -----------------------------6---R----3----------------------------

(2R6 + R3)2 + (---π----f--C1----7---)--2-

where ƒ is the frequency of the CID data signal.

The recommended components in the application cir-

cuit yield a gain 0.27 dB at 200 Hz. Clare Application

Note AN-117 Customize Caller ID Gain and Ring Detect

Voltage Threshold is a spreadsheet for trying different

component values in this circuit. Changing the CID

gain will also change the ring detection threshold and

the timing of the polarity reversal detection pulse, if

used.

For single-ended snoop circuit output of 0 dBm, set

the total resistance across the series resistors (R6/

R44 and R7/R45) to 1.4 MΩ.

3.3 Off-Hook Operation

3.3.1 Receive Signal Path

Signals to and from the telephone network appear on

the tip and ring connections of the application circuit.

Receive signals are extracted from transmit signals by

the LITELINK two-wire to four-wire hybrid. Next, the

receive signal is converted to infrared light by the

receive photodiode amplifier and receive path LED.

The intensity of the light is modulated by the receive

signal and coupled across the electrical isolation bar-

rier by a reflective dome.

On the host equipment side of the barrier, the receive

signal is converted by a photodiode into a photocur-

Rev. 9.0

www.clare.com

11

Share Link: