PTC thermistors for overcurrent
protection in telecom applications
Telecom Pair Protector (TPP), SMD
Series/Type:
Date: November 2009
© EPCOS AG 2009. Reproduction, publication and dissemination of this publication, enclosures hereto and the
information contained therein without EPCOS' prior express consent is prohibited.
Applications
Overcurrent protection for telecom applications
Suitable for line card applications e.g. POTS, access
networks, customer premises equipment (CPE) or integrated
voice data (IVD)
Features
Two resistance-matched PTCs in a plastic housing
Compliant with ITU-T standards
basic-level lightning surges (10/700 µs)
basic-level power induction (600 V, 1 A, 0.2 s)
power contact criteria A/B (230 V, 15 min.)
Compliant with GR1089 AC power contact 120 V, 25 A, 15
min.
Suitable for continuous connection to mains voltages of
110/230 V AC in tripped (high-ohmic) condition
Housing material to UL94-V0
UL approval to UL 1434 (file number E69802) for RR≥35 Ω
Tight resistance matching maintained after switching
Negligible resistance drift after reflow soldering or switching
Marked with manufacturer's logo, type designation and date
code
RoHS-compatible
Internal circuit
Options
Alternative tolerances and resistances on request
Delivery mode
T15** and T16**: Blister tape, 330-mm reel with 16-mm tape, taping to IEC 60286-3
T17** and T18**: Blister tape, 380-mm reel with 24-mm tape, taping to IEC 60286-3
General technical data
Max. operating voltage Vmax 245 V AC
Operating temperature range (V = 0) Top 20/+125 °C
Operating temperature range (V = 230 V) Top 0/+70 °C
Insulating test voltage between PTC1 and PTC2 Vins > 3 kV
Resistance matching in one housing for RR≤4.75 ΩR2R1< 0.5 Ω
Resistance matching in one housing for RR≤50 ΩR2R1< 1.0 Ω
Resistance matching in one housing for RR=75ΩR2R1< 2.0 Ω
Overcurrent protection for telecom
Telecom pair protector (TPP), SMD
Page 2 of 13Please read Cautions and warnings and
Important notes at the end of this document.
Electrical specifications and ordering codes
Type RR
Ω
∆RR
%
IR
@25°C
mA
IR
@70°C
mA
IS
@25°C
mA
ISmax
@ 230 V AC
A
Ordering code
Component height 7.5 mm
T1535 35 +15/20 110 70 230 2.5 B59535T1120A262
T1550 50 ±15 90 60 190 2.5 B59550T1120A262
Component height 8.5 mm
T1510 10 ±20 180 120 360 1.0 B59510T1120A062
T1525 25 ±20 130 85 260 2.8 B59525T1120A062
Component height 9.9 mm
T1635 35 +15/20 110 70 230 4.6 B59635T1120A062
T1650 50 ±15 90 60 190 2.5 B59650T1120A062
Component height 10.5
T1725 25 ±20 130 85 260 2.8 B59725T1120A062
T1735 35 +15/20 110 70 230 4.6 B59735T1120A062
T1750 50 ±15 90 60 190 2.5 B59750T1120A062
Component height 11.5
T1805 4.75 +15/20 160 70 370 1.0 B59805T1080A062
T1810 10 ±20 180 120 360 1.0 B59810T1120A062
T1825 25 ±20 130 85 260 2.8 B59825T1120A062
T1835 35 +15/20 110 70 230 4.6 B59835T1120A062
T1850 50 ±15 90 60 190 2.5 B59850T1120A062
T1875 75 ±20 70 40 150 2.5 B59875T1120A062
Overcurrent protection for telecom
Telecom pair protector (TPP), SMD
Page 3 of 13Please read Cautions and warnings and
Important notes at the end of this document.
Switching times and ordering codes
Type tS(typ.)
@ ISmax,
230 V AC
s
tS(typ.)
@ 1 A,
230 V AC
s
tS(typ.)
@ 500 mA,
230 V AC
s
Ordering code
Component height 7.5 mm
T1535 0.07 0.4 1.6 B59535T1120A262
T1550 0.05 0.3 1.1 B59550T1120A262
Component height 8.5 mm
T1510 3.6 3.6 16 B59510T1120A062
T1525 0.2 1.4 6 B59525T1120A062
Component height 9.9 mm
T1635 0.04 0.8 3.4 B59635T1120A062
T1650 0.1 0.6 2.4 B59650T1120A062
Component height 10.5
T1725 0.3 1.1 4 B59725T1120A062
T1735 0.04 0.8 3.4 B59735T1120A062
T1750 0.1 0.6 2.4 B59750T1120A062
Component height 11.5
T1805 4 4 20 B59805T1080A062
T1810 3.8 3.8 19.0 B59810T1120A062
T1825 0.2 1.5 6.5 B59825T1120A062
T1835 0.06 1.1 4.5 B59835T1120A062
T1850 0.13 0.8 3.1 B59850T1120A062
T1875 0.12 0.7 2.6 B59875T1120A062
Overcurrent protection for telecom
Telecom pair protector (TPP), SMD
Page 4 of 13Please read Cautions and warnings and
Important notes at the end of this document.
Internal circuit
Dimensional drawings in mm
For type T1510 and T1525 Solder pad
For type T1535 and T1550 Solder pad
Overcurrent protection for telecom
Telecom pair protector (TPP), SMD
Page 5 of 13Please read Cautions and warnings and
Important notes at the end of this document.
Dimensional drawings in mm
For type T1635 and T1650 Solder pad
For type T1725, T1735, T1750 Solder pad
For type T1805 ... T1875 Solder pad
Overcurrent protection for telecom
Telecom pair protector (TPP), SMD
Page 6 of 13Please read Cautions and warnings and
Important notes at the end of this document.
Reliability data
Test Standard Test conditions ∆R25/R25
Electrical endurance,
cycling
IEC 60738-1 Room temperature, ISmax; Vmax
Number of cycles: 10
< 20%
Electrical endurance,
constant
IEC 60738-1 Storage at Vmax /Top,max (Vmax)
Test duration: 1000 h
< 25%
Damp heat IEC 60738-1 Temperature of air: 40 °C
Relative humidity of air: 93%
Duration: 56 days
Test according to IEC 60068-2-78
< 10%
Rapid change
of temperature
IEC 60738-1 T1= Top,min (0 V), T2= Top,max (0 V)
Number of cycles: 5
Test duration: 30 min
Test according to IEC 60068-2-14, Test Na
< 10%
Vibration IEC 60738-1 Frequency range: 10 to 55 Hz
Displacement amplitude: 0.75 mm
Test duration: 3 ×2 h
Test according to IEC 60068-2-6, Test Fc
< 5%
Shock IEC 60738-1 Acceleration: 390 m/s2
Pulse duration: 6 ms; 6 ×4000 pulses
< 5%
Climatic sequence IEC 60738-1 Dry heat: T = Top,max (0 V)
Test duration: 16 h
Damp heat first cycle
Cold: T = Top,min (0 V)
Test duration: 2 h
Damp heat 5 cycles
Tests performed according to
IEC 60068-2-30
< 10%
Overcurrent protection for telecom
Telecom pair protector (TPP), SMD
Page 7 of 13Please read Cautions and warnings and
Important notes at the end of this document.
ITU performance overview and test conditions
Test
no.
ITU K20 ITU K21 ITU K45
Basic
test level
Enhanced
test level
Basic
test level
Enhanced
test level
Basic
test level
Enhanced
test level
Power induction 1 A A A A A A
2 B C B C B C
Power contact 3 D E D E D E
Lightning surge 4 F G G G G G
5 H H H I H H
Power induction
A600 V AC, R = 600 Ω, t = 0.2 s, criteria A
B600 V AC, R = 600 Ω, t = 1.0 s, with GDT, criteria A
C1500 V AC, R = 200 Ω, t = 2.0 s, with GDT, criteria A
Power contact
D230 V AC, t = 15 min, R = 10 ... 1000 Ω, criteria B
E230 V AC, t = 15 min, R = 10, 20, 40, 80, 1000 Ω, criteria B,
R = 160, 300, 600 Ω, criteria A
Lightning surge
FUc(max) =1.0kV,R=25Ω, t = 10/700 µs, without GDT, criteria A
GUc(max) =1.5kV,R=25Ω, t = 10/700 µs, without GDT, criteria A
HUc(max) =4.0kV,R=25Ω, t = 10/700 µs, with GDT, criteria A
IUc(max) =6.0kV,R=25Ω, t = 10/700 µs, with GDT, criteria A
Criteria A: no damage, function must be fulfilled.
Criteria B: no fire hazard.
Electrical requirements according to GR1089 standard for AC power contact
AC voltage: 120 V, 50 Hz, short circuit current 25 A, time 15 min, criteria A.
Overcurrent protection for telecom
Telecom pair protector (TPP), SMD
Page 8 of 13Please read Cautions and warnings and
Important notes at the end of this document.
Cautions and warnings
General
EPCOS thermistors are designed for specific applications and should not be used for purposes
not identified in our specifications, application notes and data books unless otherwise agreed
with EPCOS during the design-in-phase.
Ensure suitability of thermistor through reliability testing during the design-in phase. The ther-
mistors should be evaluated taking into consideration worst-case conditions.
Storage
Store thermistors only in original packaging. Do not open the package before storage.
Storage conditions in original packaging: storage temperature 25 °C ... +45 °C, relative hu-
midity ≤75% annual mean, maximum 95%, dew precipitation is inadmissible.
Avoid contamination of thermistors surface during storage, handling and processing.
Avoid storage of thermistor in harmful environment with effect on function on long-term opera-
tion (examples given under operation precautions).
Use thermistor within the following period after delivery:
Through-hole devices (housed and leaded PTCs): 24 months
Motor protection sensors, glass-encapsulated sensors and probe assemblies: 24 months
Telecom pair and quattro protectors (TPP, TQP): 24 months
Leadless PTC thermistors for pressure contacting: 12 months
Leadless PTC thermistors for soldering: 6 months
SMDs in EIA sizes 3225 and 4032, and for PTCs with metal tags: 24 months
SMDs in EIA sizes 0402, 0603, 0805 and 1210: 12 months
Handling
PTCs must not be dropped. Chip-offs must not be caused during handling of PTCs.
Components must not be touched with bare hands. Gloves are recommended.
Avoid contamination of thermistor surface during handling.
Soldering (where applicable)
Use rosin-type flux or non-activated flux.
Insufficient preheating may cause ceramic cracks.
Rapid cooling by dipping in solvent is not recommended.
Complete removal of flux is recommended.
Standard PTC heaters are not suitable for soldering.
Overcurrent protection for telecom
Telecom pair protector (TPP), SMD
Page 9 of 13Please read Cautions and warnings and
Important notes at the end of this document.
Mounting
Electrode must not be scratched before/during/after the mounting process.
Contacts and housing used for assembly with thermistor have to be clean before mounting. Es-
pecially grease or oil must be removed.
When PTC thermistors are encapsulated with sealing material, the precautions given in chapter
"Mounting instructions", "Sealing and potting" must be observed.
When the thermistor is mounted, there must not be any foreign body between the electrode of
the thermistor and the clamping contact.
The minimum force of the clamping contacts pressing against the PTC must be 10 N.
During operation, the thermistor’s surface temperature can be very high. Ensure that adjacent
components are placed at a sufficient distance from the thermistor to allow for proper cooling at
the thermistors.
Ensure that adjacent materials are designed for operation at temperatures comparable to the
surface temperature of thermistor. Be sure that surrounding parts and materials can withstand
this temperature.
Avoid contamination of thermistor surface during processing.
Operation
Use thermistors only within the specified temperature operating range.
Use thermistors only within the specified voltage and current ranges.
Environmental conditions must not harm the thermistors. Use thermistors only in normal at-
mospheric conditions. Avoid use in deoxidizing gases (chlorine gas, hydrogen sulfide gas, am-
monia gas, sulfuric acid gas etc), corrosive agents, humid or salty conditions. Contact with any
liquids and solvents should be prevented.
Be sure to provide an appropriate fail-safe function to prevent secondary product damage
caused by abnormal function (e.g. use VDR for limitation of overvoltage condition).
Overcurrent protection for telecom
Telecom pair protector (TPP), SMD
Page 10 of 13Please read Cautions and warnings and
Important notes at the end of this document.
Symbols and terms
A Area
Cth Heat capacity
f Frequency
I Current
Imax Maximum current
IRRated current
IPTC PTC current
IrResidual currrent
Ir,oil Residual currrent in oil (for level sensors)
Ir,air Residual currrent in air (for level sensors)
IRMS Root-mean-square value of current
ISSwitching current
ISmax Maximum switching current
LCT Lower category temperature
N Number (integer)
NcOperating cycles at Vmax, charging of capacitor
NfSwitching cycles at Vmax, failure mode
P Power
P25 Maximum power at 25 °C
Pel Electrical power
Pdiss Dissipation power
Rmin Minimum resistance
RRRated resistance
∆RRTolerance of RR
RPParallel resistance
RPTC PTC resistance
Rref Reference resistance
RSSeries resistance
R25 Resistance at 25 °C
R25,match Resistance matching per reel/ packing unit at 25 °C
∆R25 Tolerance of R25
T Temperature
t Time
TAAmbient temperature
taThermal threshold time
TCFerroelectric Curie temperature
Overcurrent protection for telecom
Telecom pair protector (TPP), SMD
Page 11 of 13Please read Cautions and warnings and
Important notes at the end of this document.
tESettling time (for level sensors)
TRRated temperature
Tsense Sensing temperature
Top Operating temperature
TPTC PTC temperature
tRResponse time
Tref Reference temperature
TRmin Temperature at minimum resistance
tSSwitching time
Tsurf Surface temperature
UCT Upper category temperature
V or Vel Voltage (with subscript only for distinction from volume)
VRMS Root-mean-square value of voltage
VBD Breakdown voltage
Vins Insulation test voltage
Vlink,max Maximum link voltage
Vmax Maximum operating voltage
Vmax,dyn Maximum dynamic (short-time) operating voltage
Vmeas Measuring voltage
Vmeas,max Maximum measuring voltage
VRRated voltage
VPTC Voltage drop across a PTC thermistor
αTemperature coefficient
∆Tolerance, change
δth Dissipation factor
τth Thermal cooling time constant
λFailure rate
Lead spacing (in mm)
Abbreviations / Notes
Surface-mount devices
* To be replaced by a number in ordering codes, type designations etc.
+ To be replaced by a letter
All dimensions are given in mm.
The commas used in numerical values denote decimal points.
Overcurrent protection for telecom
Telecom pair protector (TPP), SMD
Page 12 of 13Please read Cautions and warnings and
Important notes at the end of this document.
The following applies to all products named in this publication:
1. Some parts of this publication contain statements about the suitability of our products for
certain areas of application. These statements are based on our knowledge of typical re-
quirements that are often placed on our products in the areas of application concerned. We
nevertheless expressly point out that such statements cannot be regarded as binding
statements about the suitability of our products for a particular customer application.
As a rule, EPCOS is either unfamiliar with individual customer applications or less familiar
with them than the customers themselves. For these reasons, it is always ultimately incum-
bent on the customer to check and decide whether an EPCOS product with the properties de-
scribed in the product specification is suitable for use in a particular customer application.
2. We also point out that in individual cases, a malfunction of electronic components or
failure before the end of their usual service life cannot be completely ruled out in the
current state of the art, even if they are operated as specified. In customer applications
requiring a very high level of operational safety and especially in customer applications in
which the malfunction or failure of an electronic component could endanger human life or
health (e.g. in accident prevention or lifesaving systems), it must therefore be ensured by
means of suitable design of the customer application or other action taken by the customer
(e.g. installation of protective circuitry or redundancy) that no injury or damage is sustained by
third parties in the event of malfunction or failure of an electronic component.
3. The warnings, cautions and product-specific notes must be observed.
4. In order to satisfy certain technical requirements, some of the products described in this
publication may contain substances subject to restrictions in certain jurisdictions (e.g.
because they are classed as hazardous). Useful information on this will be found in our Ma-
terial Data Sheets on the Internet (www.epcos.com/material). Should you have any more de-
tailed questions, please contact our sales offices.
5. We constantly strive to improve our products. Consequently, the products described in this
publication may change from time to time. The same is true of the corresponding product
specifications. Please check therefore to what extent product descriptions and specifications
contained in this publication are still applicable before or when you place an order. We also
reserve the right to discontinue production and delivery of products. Consequently, we
cannot guarantee that all products named in this publication will always be available. The
aforementioned does not apply in the case of individual agreements deviating from the fore-
going for customer-specific products.
6. Unless otherwise agreed in individual contracts, all orders are subject to the current ver-
sion of the "General Terms of Delivery for Products and Services in the Electrical In-
dustry" published by the German Electrical and Electronics Industry Association
(ZVEI).
7. The trade names EPCOS, BAOKE, Alu-X, CeraDiode, CSMP, CSSP, CTVS, DeltaCap,
DSSP, MiniBlue, MiniCell, MKK, MLSC, MotorCap, PCC, PhaseCap, PhaseCube,
PhaseMod, PhiCap, SIFERRIT, SIFI, SIKOREL, SilverCap, SIMDAD, SIMID, SineFormer,
SIOV, SIP5D, SIP5K, ThermoFuse, WindCap are trademarks registered or pending
in Europe and in other countries. Further information will be found on the Internet at
www.epcos.com/trademarks.
Important notes
Page 13 of 13
