tisp4a270h3bj Bourns, Inc., tisp4a270h3bj Datasheet - Page 8

• Manufacturer Part Number: tisp4a270h3bj
• Description: Lcas R Line Protector
• Manufacturer: Bourns, Inc.

Box A: The voltage rating of the break and ring return switches and their isolation decreases with temperature. At the minimum LCAS
operating temperature of -40 °C, the switch rating is ±310 V.
Box B: A switch pole voltage rating to ground is reduced by any opposing bias voltage applied to the other pole. For battery-backed ringing
the d.c. bias on T
R
Box C: Allowing for the extreme condition of a power fault at -40 °C, the overvoltage protector V
exceed +250 V and -310 V. The IEEE Standard C62.37.1-2000, IEEE Guide for the Application of Thyristor Surge Protective Devices, pp 25-27
recommends a factor of 1.15 for the ratio of the power fault V
+217 V and -270 V.
Box D: From the V
Box E: Derating the 25 °C V
A further rating check has to be done on the ringing access switch, SW4. The limit condition is in the negative ringing polarity. The applied
ringing voltage to the R
the a.c. ringing levels must not exceed 117 V rms and 102 V rms respectively. In IVD (Integrated Voice Data) applications the a.c. ringing level
must be reduced by the level of digital signal applied to the line. For a 20 V peak ADSL signal level, the ringing voltages reduce to 103 V rms
and 89 V rms respectively.
Figure 9 shows a typical application circuit. Fuses F1 and F2 need high breaking capacity to safely interrupt 40 A rms (UL 60950) and
60 A rms (Telcordia GR-1089-CORE) currents from a 600 V rms source. The Bourns
has UL recognition for these UL and Telcordia standards. The TISP4A270H3BJ is overload rated to carry currents up to 60 A rms for the time
period that it takes the fuse to operate.
LINE
Calculation of the TISP4A270H3BJ Voltage Values (Continued)
and T
TISP4A270H3BJ LCAS R
RING
LINE
TIP
overcurrent
voltage ratings to ground become +250 V and -310 V at -40 °C.
protectors
B1250T
RINGING
B1250T
Fuse
(BO)
F1
F2
MODEM
values the values of protector 25 °C V
ADSL
RINGING
is zero. Bias voltages are applied to the R
TISP4A270H3
DRM
TI
terminal must not exceed -205 V when the R
SP4165H3
down to the LCAS minimum operating temperature gives -40 °C V
G
R
C1
Figure 9. ADSL IVD using Common Protection
V
High
pass
filter
ADSL
LINE
pass
filter
Low
Protector
DRM
(BO)
were determined as +160 V and -222 V.
T
R
to the 25 °C V
BAT
LINE
LINE
and T
'7581 LCAS
R
LINE
BAT
RINGING
R1
V
V
BAT
generator
RING
poles by the SLIC. For SLIC output levels of zero and -60 V, the
(BO)
terminal is at +250 V. For a battery voltage of -40 V and -60 V
Ringing
access
Customers should verify actual device performance in their specific applications.
switch
switch
return
Ring
Ring
SW3
SW4
. Applying this factor makes the 25 °C V
®
Telefuse
T
™
RINGING
R2
type B1250T is a surface mount fuse which
switch
Break
(BO)
SW2
DRM
at its highest temperature must not
switch
Break
SW1
values of +148 V and -206 V.
Specifications are subject to change without notice.
T
APRIL 2002 - REVISED FEBRUARY 2005
SD
R
V
LATCH
T
F
V
INPUT
D
BAT
GND
BAT
BAT
DD
GND
AI4AITAM A
(BO)
SLIC
voltage values
V
bat