Table 7. Break-Before-Make Operation (Ringing to Idle/Talk Transition)

Ring

Ring

Break

Return

Access Line Access

Switches

Switch

Switch

Switches

Access Input

TSD

State

Timing

1 & 2

3

4

5 & 6

0V

5V

Float

Ringing

-

Open

Closed

Closed

Open

5V

5V

Float

All Off

Hold this state for <= 25ms.

Open

Open

Closed

Open

SW4 waiting for zero current to

turn off.

5V

5V

Float

All Off

Zero current has occurred.

Open

Open

Open

Open

SW4 has opened.

0V

0V

Float

Idle/Talk

Release Break Switches

Closed

Open

Open

Open

Alternate “Break-Before-Make” Operation

Note that the “break-before-make” operation can also be achieved using TSD as an input. In lines 2 & 3 of Table 7,

instead of using the logic input pins to force the “all off” state, force TSD to ground. This will override the logic inputs

and also force the all off state. Hold this state for 25 ms. During this 25 ms all off state, toggle the inputs from the

ringing state (Input=5V, Access=0V) to the idle/talk state (Input=0V, Access=0V). After 25 ms, release TSD to return

switch control to the input pins which will set the idle talk state.

When using the CPC7582 in this mode, forcing TSD to ground will override the INPUT pins and force an all off state.

Setting TSD to +5V will allow switch control via the logic INPUT pins. However, setting TSD to +5V will also disable

the thermal shutdown mechanism. This is not recommended. Therefore, to allow switch control via the logic INPUT

pins, allow TSD to float.

Thus when using TSD as an input, the two recommended states are 0 (overrides logic input pins and forces all off

state) and float (allows switch control via logic input pins and thermal shutdown mechanism is active). This may

require use of an open collector buffer.

www.clare.com

6

CPC7582

Rev. 1.0

Table 8. Electrical Specifications, Protection Circuitry

Parameters

Conditions

Symbol

Min

Typ

Max

Units

Parameters Related to Diodes

(in Diode Bridge)

Voltage Drop @ Continuous

Apply +/-dc current limit of break

Forward

-

2.1

3

V

Current (50/60 Hz)

switches

Voltage

Voltage Drop @ Surge

Apply +/-dynamic current limit of

Forward

-

5

-

V

Current

break switches

Voltage

Parameters Related to

Surge Current

-

-

-

-

*

A

Trigger Current (+25˚C)

-

I

TRIG

-60

-

mA

Hold Current (+25˚C)

-

I

HOLD

-

100

-

mA

Trigger Current (+85˚C)

-

I

TRIG

-35

-

mA

Hold Current (+85˚C)

I

HOLD

60

70

-

mA

Gate Trigger Voltage

Trigger Current

-

V

-

V

V

Reverse Leakage Current

V

BAT

-

-

-

1.0

µA

0.5A t = 0.5 ms

V

on

--3

-

V

2.0A t = 0.5 ms

-

-

-5

-

V

* Passes GR1089 & ITU-T K.20 with appropriate secondary protection in place.