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JULY 2000 - REVISED FEBRUARY 2005
Specifications are subject to change without notice.
Customers should verify actual device performance in their specific applications.
TISP4xx0L3LM Overvoltage Protector Series
TISP4070L3LM, TISP4350L3LM
BIDIRECTIONAL THYRISTOR OVERVOLTAGE PROTECTORS
How To Order
LM Package (Top View)
Ion-Implanted Breakdown Region
Precise and Stable Voltage
Low Voltage Overshoot under Surge
Device Symbol
These devices are designed to limit overvoltages on the telephone line. Overvoltages are normally caused by a.c. power system or lightning
flash disturbances which are induced or conducted on to the telephone line. A single device provides 2-point protection and is typically used
for the protection of 2-wire telecommunication equipment (e.g. between the Ring to Tip wires for telephones and modems). Combinations of
devices can be used for multi-point protection (e.g. 3-point protection between Ring, Tip and Ground).
The protector consists of a symmetrical voltage-triggered bidirectional thyristor. Overvoltages are initially clipped by breakdown clamping until
the voltage rises to the breakover level, which causes the device to crowbar into a low-voltage on state. This low-voltage on state causes the
current resulting from the overvoltage to be safely diverted through the device. The high crowbar holding current prevents d.c. latchup as the
diverted current subsides.These protectors are guaranteed to voltage limit and withstand the listed lightning surges in both polarities.
After a Type A surge (200 A, 10/160, and 100 A, 10/560) the equipment is allowed to be non-operational or operational. For an operational
pass, series resistance must be added to reduce the Type A currents to within the TISP4xxxL3LM ratings (50 A, 10/160 and 30 A, 10/560).
Alternatively, a series fuse with an I
2
t greater than 0.45 A
2
s and less than 5.6 A
2
s could be used to give a non-operational pass. After a Type B
surge the equipment must be operational. As the TISP4xxxL3LM has a current rating of 40 A, will survive both Type B surges, metallic (25 A,
9/720) and longitudinal (37.5 A, 9/720), giving an operational pass to Type B surges.
For metallic protection, the TISP4350L3LM is connected between the Ring and Tip conductors. For longitudinal protection two TISP4350L3LM
protectors are used; one between the Ring conductor to ground and the other between the Tip conductor to ground. The FCC Part 68 B type
ringer has voltages of 56.5 V d.c. and up to 150 V rms a.c., giving a peak voltage of 269 V. The TISP4350L3LM will not clip the B type ringing
voltage as it has a high impedance up to 275 V.
The TISP4070L3LM should be connected after the hook switch to protect the following electronics. As the TISP4070L3LM has a high
impedance up to 58 V, it will switch off after a surge and not be triggered by the normal exchange battery voltage.
Description
Device
V
DRM
V
V
(BO)
V
‘4070
58
70
‘4350
275
350
Ring-Tip Protection............................................ TISP4350L3LM
Electronics Protection ....................................... TISP4070L3LM
Rated for UL 1950, ITU-T and TIA/EIA-IS-968
Surge
Type
Standard
Wave
Shape
I
TSP
A
A
TIA/EIA-IS-968
(formerly FCC Part 68)
10/160
50
10/560
30
B
TIA/EIA-IS-968
UL 1950/ ITU-T K.21
9/720
10/700
40
NC - No internal connection on pin 2
NC
R(B)
T(A)
MD4XATA
1
2
3
T
R
SD4XAA
Terminals T and R correspond to the
alternative line designators of A and B
*RoHS Directive 2002/95/EC Jan 27 2003 including Annex
Device
Package Type
Carrier
Quantity
TISP4070L3
LM (Straight Lead DO-92)
Bulk Pack
2 000
TISP4070L3LM
TISP4350L3
LM (Straight Lead DO-92)
Bulk Pack
2 000
TISP4350L3LM
TISP4070L3LM-S
TISP4350L3LM-S
For Standard
Termination Finish
Order As
For Lead Free
Termination Finish
Order As
*RHAVALABE
VRSONS