PTCTL
www.vishay.com
Vishay BCcomponents
PTC Thermistors, Overload Protection for Telecommunication
FEATURES
Wide resistance range in telecom area from 4
to 70
Fast protection against power contact faults
Withstand high overload currents of up to 10 A
High voltage withstanding capabilities for the
larger sized thermistors (up to 600 V)
Good tracking over a wide temperature range for
all matched or binned thermistors (matching at
85 C 2 x matching at 25 C)
UL1434 approved types available (XGPU2)
All telecom PTCs are coated with a high temperature
silicon lacquer (UL 94 V-0) to protect them from any harsh
environments and to improve their lifetime
QUICK REFERENCE DATA
Material categorization: for definitions of compliance
PARAMETER VALUE UNIT
please see www.vishay.com/doc?99912
Maximum voltage (RMS or DC) 220 to 600 V
RMS
Maximum holding current (I ) 100 to 175 mA APPLICATIONS
nt
Resistance at 25 C (R )8 to 50
25 Over-temperature/over-load protection:
Tolerance on R value 15 to 25 % Main distribution frame (MDF)
25
Maximum overload current I 0.6 to 10.0 A Central office switching (C.O.)
ol
Subscriber terminal equipment (T.E.)
Tripping time at 1 A 1 to 40 s
Set-top box (S.B.)
Operating temperature range
0 to 70 (95) C
at max. voltage
MARKING
Clear marking on a gray coated body
BC and R value
25
ELECTRICAL DATA AND ORDERING INFORMATION
MAX. I
max.
NON-TRIP TRIP
RESISTANCE TRIP TIME AT
CURRENT CURRENT
MATCHING V APPLICATION ORDERING PART
max.
at 1 A V
max.
(2)
() (V ) AREA NUMBERS
RMS
t
R TOL. I atT I atT I
25 nt t max. max.
() (%) (mA) (C) (mA) (C) (S) (A)
25 20 1.0 220 70 70 200 25 2.5 4.0 C.O. PTCTL4MR250GTE
10 20 1.0 230 100 70 250 25 3.0 2.0 MDF; ISDN PTCTL3MR100GTE
25 15 no 245 70 70 200 25 5.0 2.6 C.O. PTCTL4NR250GTE
16 20 no 245 140 55 270 25 8.0 1.6 T.E. PTCTL6NR160GTE
10 20 no 245 140 55 270 25 8.0 2.0 T.E. PTCTL6NR100GTE
25 20 1.0 250 70 70 175 25 1.3 3.2 MDF; C.O. PTCTL3MR250HTE
10 20 no 250 100 70 450 0 40.0 10.0 T.E. PTCTL8NR100HBE
8 25 0.5 285 135 95 400 25 6.0 0.6 MDF; ISDN PTCTL4MR080JBE
16 25 no 300 100 70 250 25 2.0 2.6 MDF; T.E. PTCTL3NR160KTE
10 20 no 350 100 70 270 25 4.0 1.0 T.E.; S.B. PTCTL4NR100LBE
10 20 1.0 350 100 70 270 25 4.0 1.0 C.O. PTCTL4MR100LTE
50 20 1.0 600 50 70 140 25 1.0 1.0 C.O. PTCTL4MR500SBE
35 20 3.0 600 70 70 600 0 3.0 1.0 C.O. PTCTL4MR350STE
25 20 0.5 600 70 70 170 25 2.5 2.0 C.O. PTCTL4MR250STE
25 20 0.5 600 70 70 170 25 5.0 2.0 C.O. PTCTL6MR250STE
(1)
10 20 0.5 600 175 25 400 25 7.0 1.0 C.O. PTCTL7MR100SBE
(1)
10 20 no 600 175 25 400 25 7.0 1.0 T.E.; S.B. PTCTL7NR100SBE
Notes
All types pass ITU-T K20-21-45 telecommunication protection recommendation
(1)
UL 1434 approved types and compatible with UL1459 and GR1089
(2)
MDF: Main Distribution Frame; C.O.: Central Office Switching; T.E.: Subscriber Terminal Equipment; S.B.: Set-top Box
Revision: 13-Nov-15 Document Number: 29070
1
For technical questions, contact: nlr@vishay.com
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
PTCTL
www.vishay.com
Vishay BCcomponents
OVERCURRENT PROTECTION OF TELECOMMUNICATION LINES
The PTC thermistor must protect the telephone line circuit In case of overcurrent due to short-term induction of
against overcurrent which may be caused by the following alternating voltages, currents of several amperes with
events: voltages as high as 650 V can be present for several
RMS
seconds.
Surges due to lightning strikes on or near to the line plant.
For standard high voltage applications, resistance values
Short-term induction of alternating voltages from adjacent
from 25 to 50 are available. However, ISDN networks
power lines or railway systems, usually caused when
which carry high-frequency sound and vision, need lower
these lines or systems develop faults.
line impedance.
Direct contact between telephone lines and power lines.
Telecommunication designers are therefore demanding
To provide good protection under such conditions a PTC
high voltage thermistors with much lower R values, which
25
thermistor is connected in series with each line, usually as
places even greater demands on the manufacture of PTC
secondary protection; see Typical Telephone Line drawing
thermistors. For these applications PTC thermistors which
fig. 1. However, even with primary line protection (usually a
have a R value of 10 with voltages in the 300 V to
25 RMS
gas discharge tube), the PTC thermistor must fulfil severe
600 V range are available.
RMS
requirements.
In a typical telephone line application, two PTC thermistors
Surge pulses of up to 2 kV can occur and in order to
are used, one each for the tip and ring (or A and B) wire
withstand short-term power induction the PTC thermistor
together with their series resistors. For good line balance it
must withstand high voltages. If the line has primary
is important that the thermistor and resistor pairs are
protection a 220 V to 300 V PTC thermistor is adequate.
matched.
Without primary protection, however, a 600 V PTC device is
necessary. Vishay BCcomponents manufacturers a range of
PTC thermistors (see Electrical Data and Ordering
Information Table) covering both requirements.
In the case of direct contact between the telephone line and
a power line, the PTC thermistor must withstand very high
inrush power at normal mains voltage. Under such
conditions, overload currents of up to 10 A on a 230 V mains
could occur for up to several hours. To handle this power,
the resistance/temperature characteristic of the thermistor
must have a very steep slope and the ceramic must be
extremely homogeneous.
PRIMARY SECONDARY
PROTECTION PROTECTION
(OPTIONAL)
+ +
PTC PTC SUBSCRIBER
LOOP
INTERFACE
subscriber
voltage
CIRCUIT
lines
clamp
(SLIC)
OR
TRANSFORMER
+ +
PTC
MDF
Fig. 1 - Typical telephone line showing where PTC thermistors can be used for overcurrent protection.
Revision: 13-Nov-15 Document Number: 29070
2
For technical questions, contact: nlr@vishay.com
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000