SGS Thomson Microelectronics SSRP105B1 Datasheet

®

SSRP105B1

Application Specific Discretes

DUAL ASYMMETRICAL OVERVOLTAGE

ASD™

MAIN APPLICATIONS

Where asymmetrical protection against lightning
strikes andother transient overvoltages is required :

Solid-State relays

■

SLIC with integrated ring generator

■

DESCRIPTION

The SSRP105B1 is a dual asymmetrical transient
voltage suppressor designed to protect a
solid-state ring relay or SLICs with integrated ring
generator from overvoltages.
The asymmetrical protection configuration is
necessary to allow the use of all different types of
ringing schemes.

FEATURES

■ Dual bi-directional asymmetrical protection

Stand-off voltages:

● Between Line and Ground

+105V for positive voltages

-180V for negative voltages

●

Between Line and Line

+180V for positive voltages

-180V for negative voltages

■

Peak pulse current: IPP= 50A (5/310µs)

■

Holding current:

●

IH+= 100mA

●

IH-= 150mA

PROTECTION FOR TELECOM LINE

SO-8

FUNCTIONAL DIAGRAM

GND

8

GND

7

GND

6

5

GND

RING

1

TIP

NC

2

NC

3

4

COMPLY WITH THE FOLLOWING STANDARDS

Peak Surge

Voltage

(V)

ITU-T K20 / K21
VDE0433
IEC61000-4-5

1500 10/700 5/310 38 ­2000 10/700 5/310 50 -

Level 3
Level 4

FCC Part 68

1500

800

BELLCORE
GR1089 First level

TM: ASD is trademarks of STMicroelectronics.

October 2002 - Ed: 1A

2500
1000

Voltage

Waveform

(µs)

10/700

1.2/50

10/160
10/560

2/10

10/1000

Current

Waveform

(µs)

5/310

8/20

10/160
10/560

2/10

10/1000

Required

Peak

current

(A)

50

100
200

100
500

100

Min. serial

resistor to meet

standards

(Ω)

-

-

18
10

10
19

1/6

SSRP105B1

APPLICATION INFORMATION
Fig.1: Topologyof the classical line card protection.

2nd

stage

R

TIP

SLIC

R

RING

Ring generator

LINE

PTC

PTC

1st

stage

±V

RING

VRINGBAT

The classical line card requiresprotection before the
ring relay and a second one for the SLIC (

figure 1

).

The use of new SLICs with integrated ring
generator or board based on solid-state ring relay
suppresses this second protection (

figure 2

Then, the only remaining stage, located between
the line and the ring relay, has to optimize the
protection.
The classical symmetrical first stage protector
becomes not sufficient to avoid any circuit
destruction during surges.

Fig. 2: Classical use of the SSRP105B1.

PTC

PTC

SSRP105B1

(*) SLIC with integrated ring generator or Solid-State Relay

R

R

The SSRP105B1 device takes into account this
fact and is based on asymmetrical voltage
characteristics (

figure 3a

). The ring signal being
shifted back by the battery voltage, the
SSRP105B1 negative breakover value V

).

greater than the positive one V

BO+

guaranteesaprotection operation very close tothe
peak of the normal operating voltage without any
disturbance of the ring signal.

TIP

(*)

SLIC

RING

BO-

. This point

is

Fig. 3: SSRP105B1 electrical characteristics.

a: Line to ground characteristics.

I

VBO-

BO+

V

In addition with the 2 crowbar functions which
perform the protection of both TIP and RING lines
versus ground, athird cell assumesthe differential
mode protection of the SLIC. The breakover
voltage values of this third cell are the same for

2/6

V

b: Line to line characteristics.

I

VBO-

BO+

V

both positive and negative parts of the
characteristics and are equivalent to the negative
breakover voltage valueof theTIP and RINGlines
versus GND cells (

figure 3b

).

V