TISP4350L3BJR Bourns Inc., TISP4350L3BJR Datasheet - Page 11

• Manufacturer Part Number: TISP4350L3BJR
• Description: SURGE SUPP 275V BIDIR DO-214AA
• Manufacturer: Bourns Inc.

Specifications of TISP4350L3BJR

• Package / Case: DO-214AA, SMB
• Voltage - Breakover: 350V
• Voltage - Off State: 275V
• Voltage - On State: 3V
• Current - Hold (ih): 120mA
• Number Of Elements: 1
• Capacitance: 30pF
• Breakover Current Ibo Max: 13 A
• Rated Repetitive Off-state Voltage Vdrm: 275 V
• Off-state Leakage Current @ Vdrm Idrm: 0.005 mA
• Forward Voltage Drop: 3 V
• Mounting Style: SMD/SMT
• Current - Peak Pulse (8 X 20µs): -
• Current - Peak Pulse (10 X 1000µs): -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Fuse power cross current capability can be determined from its time-current curve. The fuse must be rated to break the current at the applied
power cross a.c. voltage level.
There are two areas of fuse criteria; surge capability (TIA/EIA-IS-968 (FCC Part 68) impulse) and power cross capability (UL60950 clause 6.4
and annex NAC).
To survive an impulse, a fuse must have a melting I 2 t rating greater than the impulse I 2 t. The fuse I 2 t rating should be specified for the impulse
waveshape current as the normal d.c. rating may not result in adiabatic conditions. Alternatively, the fuse may be specified for a rated current
under the impulse waveshape conditions.
An exponentially decaying impulse with a current amplitude I PP and 50 % amplitude decay time of t D has an I 2 t value of 0.72 I PP 2 t D .
Test waveforms have tolerances and the formula can be approximated to I PP 2 t D , giving about a 40 % allowance to cover tolerances, e.g.
+5 % on I PP and +30 % on t D . Using the approximate formula, the I 2 t values for typical waveforms are shown in the table below.
To survive both the Type A surges, a fuse I
they are rated for 60 A, 600 V a.c. interruption.
Fuses must not operate on the Type B surge. To survive a 37.5 A Type B surge, the fuse needs to have an I
operational pass for TIA/EIA-IS-968 Type A impulses is allowed; this could be a design approach with the TISP4xxxL3, which is likely to fail
short with Type A impulses. A fuse with an I
impulse fault mode disconnects the modem from the line (avoiding a permanent off-hook condition). The Bel SMP 500 fuse starts to operate at
60 % of the specified Type A impulse current levels and is rated for 60 A, 600 V a.c. interruption.
Like TIA/EIA-IS-968, K.21 requires an operation pass on a 37.5 A, 5/310 transverse current impulse, giving a minimum fuse I
value may be increased when the coordination test requirements are included. Depending on the conformance level, basic or enhanced, an
a.c. power induction operational pass requires a minimum fuse I
The TISP4xxxL3BJ conducts current for periods greater than the power cross test times, Figure 2, so the TISP4xxxL3BJ is not a major factor
in UL 60950 compliance. The main design task for UL 60950 power cross is about enclosure design and the selection of the other components
that are subject to power cross. A UL specified fuse together with a TISP4xxxL3BJ gives a simple approach to meeting the power cross
requirements.
Fuse Values
Fuses for TIA/EIA-IS-968
Fuses for ITU-T Recommendation K.21
TISP4xxxL3BJ and UL 60950 Power Cross
TISP4xxxL3BJ Overvoltage Protector Series
TIA/EIA-IS-968 Type A (FCC Part 68)
TIA/EIA-IS-968 Type B (FCC Part 68)
UL 60950 / ITU-T K.21
Telcordia (formally Bellcore)
GR-1089-CORE
UL 60950, Annex NAC testing requires that the total I
K.21 has a.c. induction withstand tests of 1 A
Specification
2
2
t value of greater than 6.4 A
t greater than 0.45 A
APPLICATIONS INFORMATION
Amplitude I
2
2
s (basic) and 10 A s (enhanced)
2
t of either a 1 A
s and less than 5.6 A
37.5
37.5
200
100
500
100
A
2
2
s is needed. Fuses such as the Bel SMP 1.25 will meet this criteria and
t does not exceed 100 A
PP
Customers should verify actual device performance in their specific applications.
2
s or a 10 A
Current Wave Shape
2
2
t
s would be needed to ensure that the resultant Type A
10/1000
R
10/160
10/560
5/320
5/310
/
2/10
t
D
2
s level.
(µs)
2
s for test 1
Specifications are subject to change without notice.
2
t of greater than 0.45 A
Melting I
AUGUST 1999 - REVISED JANUARY 2007
0.45
0.45
A
6.4
5.6
2.5
10
2
s
2
t
2
t of 0.45 A
2
s. A non-
2
s. This