EPCOS B59421A0115A062 Ptc thermistors as limit temperature sensor Datasheet

PTC thermistors as
limit temperature sensors
SMD, EIA case sizes 0402, 0603 and 0805,
superior series
Series/Type:
Date:
November 2010
© EPCOS AG 2010. Reproduction, publication and dissemination of this publication, enclosures hereto and the
information contained therein without EPCOS' prior express consent is prohibited.
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Superior series
Applications
Over-temperature protection of power components
DC/DC converters
SMPS
Notebooks
Home appliances
Dimmers
Electronic ballasts
Automotive electronics
Secondary protection of battery packs
Features
Qualification based on AEC-Q200 rev. C
Suitable for reflow and wave soldering (up to 280°C)
Fast and reliable response
RoHS-compatible
UL approval to UL1434 expected 2010
Lead-free tinned terminations
Options
Other Tsense or resistance values on request
Delivery mode
Blister tape (case size 0805) or cardboard tape (case sizes 0402 and 0603), 180-mm reel
with 8-mm tape, taping to IEC 60286-3
Packing unit: 10.000 pcs. (case size 0402), 4.000 pcs. (case size 0805 and 0603)
General technical data
Max. operating voltage
Minimum operating temperature
Maximum operating temperature
Please read Cautions and warnings and
Important notes at the end of this document.
(V ≤ Vmax)
(V ≤ Vmax)
Page 2 of 32
Vmax
Tmin
Tmax
32
40
125 °C or Tsense,1 +25 °C
whichever is higher
V DC
°C
°C
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
A421, A641
Electrical specifications and ordering codes
RR
(V ≤ Vmax)
Ω
∆RR
%
Tsense,1
(@ 4.7 kΩ)
°C
Tsense,2
(@ 47 kΩ)
°C
Ordering code
EIA case size 0402
470
±50
75 ±5
B59421A0075A062
470
±50
85 ±5
B59421A0085A062
470
±50
95 ±5
B59421A0095A062
470
±50
105 ±5
B59421A0105A062
470
±50
115 ±5
B59421A0115A062
470
±50
125 ±5
B59421A0125A062
470
±50
135 ±5
B59421A0135A062
EIA case size 0603
470
±50
75 ±5
90 ±7
B59641A0075A062
470
±50
85 ±5
100 ±7
B59641A0085A062
470
±50
95 ±5
110 ±7
B59641A0095A062
470
±50
105 ±5
120 ±7
B59641A0105A062
470
±50
115 ±5
130 ±7
B59641A0115A062
470
±50
125 ±5
140 ±7
B59641A0125A062
470
±50
135 ±5
150 ±7
B59641A0135A062
470
±50
145 ±5
B59641A0145A062
Note:
In order to limit self heating effects the electrical power during measurement should be below
2 mW for case size 0402 and below 4 mW for case size 0603.
Please read Cautions and warnings and
Important notes at the end of this document.
Page 3 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Electrical specifications and ordering codes
RR
(V ≤ Vmax)
Ω
∆RR Tsense,1 R
R
(Tsense,1 5°C) (Tsense,1 +5°C)
%
°C
kΩ
kΩ
R
(Tsense,1 +15°C)
kΩ
Ordering code
EIA case size 0805
680
±50 70
≤ 5.7
≥ 5.7
≥ 401)
B59721A0070A062
680
±50 80
≤ 5.7
≥ 5.7
≥ 401)
B59721A0080A062
680
±50 90
≤ 5.5
≥ 13.3
≥ 40
B59721A0090A062
680
±50 100
≤ 5.5
≥ 13.3
≥ 40
B59721A0100A062
680
±50 110
≤ 5.5
≥ 13.3
≥ 40
B59721A0110A062
680
±50 120
≤ 5.5
≥ 13.3
≥ 40
B59721A0120A062
680
±50 130
≤ 5.5
≥ 13.3
≥ 40
B59721A0130A062
Note:
In order to limit self heating effects the electrical power during measurement should be below
6 mW for case size 0805.
1) R (Tsense,1 +25 °C)
Please read Cautions and warnings and
Important notes at the end of this document.
Page 4 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Superior series
Dimensional drawings in mm
EIA case size 0402
Solder pad
Recommended maximum dimensions (mm)
EIA case size 0603
Solder pad
Recommended maximum dimensions (mm)
EIA case size 0805
Solder pad
Recommended maximum dimensions (mm)
Please read Cautions and warnings and
Important notes at the end of this document.
Page 5 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Superior series
Reliability data
Test
Electrical endurance,
cycling
Electrical endurance,
constant
Standard
IEC 60738-1
Damp heat
IEC 60738-1
Rapid change
of temperature
IEC 60738-1
Vibration I
IEC 60738-1
Vibration II
MIL-STD-202,
method 204
Bump
IEC 60738-1
IEC 60738-1
Test conditions
Room temperature: Ismax , Vmax;
Number of cycles: 100
Storage at Vmax/Top
T = 85 °C
Test duration: 1000 h
Temperature of air: 40 °C
Relative humidity of air: 93%
Duration: 56 days
Test according to IEC 60068-2-78
TLCT = 25 °C, TUCT = 125 °C
Number of cycles: 5
Test duration: 30 min
Test according to IEC 60068-2-14, test Na
Frequency: 10 - 55 - 10 Hz
Displacement amplitude: 0.75 mm, resp.
Acceleration: 50 m/s2
Test duration: 3 × 2 h
Test according to IEC 60028-2-6, test Fc
Frequency: 10 ... 2000 Hz
Displacement amplitude: 0.75 mm, resp.
Acceleration: 50 m/s2
Test duration: 3 × 2 h
Test according to IEC 60028-2-6, test Fc
Pulse shape: half-sine
Acceleration: 400 m/s2
Pulse duration: 6 ms; 6 x 4000 pulses
Test according to IEC 60068-2-27, test Ea
Dry heat: TUCT = 125 °C
Test duration: 16 h
Damp heat first cycle
Cold: TLCT = 25 °C
Test duration: 2 h
Damp heat 5 cycles
Tests performed according to
IEC 60068-2-30
Bending test
EN 130000/4.35 Components reflow-soldered to test board
Maximum bendig: 2 mm
Adhesive strength on
Shearing of the component soldered on PCB
PCB
by a force of 5 N is normal to components
longitudinal axis
Climatic sequence
IEC 60738-1
Please read Cautions and warnings and
Important notes at the end of this document.
Page 6 of 32
∆R25/R25
< 10%
< 20%
< 10%
< 10%
< 5%
< 5%
< 5%
< 10%
< 5%
No
visible
damage
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Test
Moisture resistance
Humidity
Thermal shock
Resistance to
soldering heat
ESD
Standard
AEC-Q200 / IEC
60069-2-30
AEC-Q200 /
MIL-STD-202
Method 103
AEC-Q200 / IEC
60738-1,
item 4.17
AEC-Q200 / IEC
60068-2-20, test
Tb
AEC-Q200-002
High temperature load
Please read Cautions and warnings and
Important notes at the end of this document.
Superior series
Test conditions
Test Db2, category 25/125/56
∆R25/R25
< 10%
T = 80 °C; H = 85% r.H.; t = 1000 h
V = 0.05 Vmax
< 20%
TLCT = 40 °C,
TUCT = 125 °C
Number of cycles: 1000
Soldering bath: 260 °C; t = 10 s
< 25%
150 pF/ 330 Ω; 8 kV contact discharge,
10 pulses in each polarity
Soldered PTC to PCB @ 85 °C, load
maximum operating voltage for 1.5 h on and
0.5 h off. This cycle is repeated for
1000 ±12 h
< 5%
Page 7 of 32
< 20%
< 20%
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Characteristics (typical) for case size 0402
PTC resistance RPTC versus PTC temperature TPTC
(measured at low signal voltage)
Please read Cautions and warnings and
Important notes at the end of this document.
Page 8 of 32
A421, A641
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Characteristics (typical) for case size 0402
PTC resistance RPTC versus PTC temperature TPTC
(measured at low signal voltage)
Please read Cautions and warnings and
Important notes at the end of this document.
Page 9 of 32
A421, A641
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Characteristics (typical) for case size 0402
PTC resistance RPTC versus PTC temperature TPTC
(measured at low signal voltage)
Please read Cautions and warnings and
Important notes at the end of this document.
Page 10 of 32
A421, A641
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Characteristics (typical) for case size 0402
PTC resistance RPTC versus PTC temperature TPTC
(measured at low signal voltage)
Please read Cautions and warnings and
Important notes at the end of this document.
Page 11 of 32
A421, A641
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Characteristics (typical) for case size 0603
PTC resistance RPTC versus PTC temperature TPTC
(measured at low signal voltage)
Please read Cautions and warnings and
Important notes at the end of this document.
Page 12 of 32
A421, A641
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Characteristics (typical) for case size 0603
PTC resistance RPTC versus PTC temperature TPTC
(measured at low signal voltage)
Please read Cautions and warnings and
Important notes at the end of this document.
Page 13 of 32
A421, A641
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Characteristics (typical) for case size 0603
PTC resistance RPTC versus PTC temperature TPTC
(measured at low signal voltage)
Please read Cautions and warnings and
Important notes at the end of this document.
Page 14 of 32
A421, A641
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Characteristics (typical) for case size 0603
PTC resistance RPTC versus PTC temperature TPTC
(measured at low signal voltage)
Please read Cautions and warnings and
Important notes at the end of this document.
Page 15 of 32
A421, A641
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Characteristics (typical) for case size 0805
PTC resistance RPTC versus PTC temperature TPTC
(measured at low signal voltage)
Please read Cautions and warnings and
Important notes at the end of this document.
Page 16 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Characteristics (typical) for case size 0805
PTC resistance RPTC versus PTC temperature TPTC
(measured at low signal voltage)
Please read Cautions and warnings and
Important notes at the end of this document.
Page 17 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Characteristics (typical) for case size 0805
PTC resistance RPTC versus PTC temperature TPTC
(measured at low signal voltage)
Please read Cautions and warnings and
Important notes at the end of this document.
Page 18 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Characteristics (typical) for case size 0805
PTC resistance RPTC versus PTC temperature TPTC
(measured at low signal voltage)
Please read Cautions and warnings and
Important notes at the end of this document.
Page 19 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Superior series
Mounting instructions
1
Soldering
1.1
Leaded PTC thermistors
Leaded PTC thermistors follow the solderability requirements of IEC 60068-2-20.
During soldering, care must be taken that the thermistors are not damaged by excessive heat.
The following maximum temperatures, maximum time spans and minimum distances have to be
observed:
Solderability
Resistance to
soldering heat
Solder containing lead
(SnPb 60/40)
Solder bath temperature 230 °C
Soldering time 3 s
Soldering iron temperature 350 °C
Soldering time 3 s
Lead-free solder
(Sn96.5Ag3Cu0.5)
Solder bath temperature 245 °C
Soldering time 3 s
Solder bath temperature 260 °C
Soldering time 10 s
Distance to thermistor has to be ≥6 mm. Under more severe soldering conditions the resistance
may change. Soldering conditions for wave soldering are given in chapter 1.4.1.
1.2
Leadless PTC thermistors
In case of PTC thermistors without leads, soldering is restricted to devices which are provided
with a solderable metallization. The temperature shock caused by the application of hot solder
may produce fine cracks in the ceramic, resulting in changes in resistance.
In addition, soldering methods should be employed which permit short soldering times.
Soldering conditions for wave soldering are given in chapter 1.4.1.
1.3
SMD PTC thermistors
The notes on soldering leadless thermistors also apply to the SMD versions (refer to
IEC 60068-2-58). Soldering conditions for wave soldering are given in chapter 1.4.1., for reflow
soldering in chapter 1.4.2.
1.3.1
Chrome/nickel/tin terminations
(Sizes 0402, 0603, 0805, 1210)
As shown in the figure above, the terminations consists of three metallic layers. A primary chrome
layer provides for good electrical contact. "Leaching" is prevented by a nickel barrier layer. The
outer tin coating prevents corrosion of the nickel and ensures good component solderability.
Please read Cautions and warnings and
Important notes at the end of this document.
Page 20 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
1.3.2
Superior series
Test methods for wetting and resistance to soldering heat
a) Solder bath method according to IEC 60068-2-58
Applicable for SMD components with wire or tag terminations. In case the SMD-component does
not have a completely closed housing, only the wires or tags may be immersed into the solder
bath.
Wetting test
Resistance to
soldering heat
Lead-free solder
(Sn96.5Ag3Cu0.5)
Bath temperature 250 °C
Soldering time 3 s
Bath temperature 260 °C
Soldering time 10 s
Solder containing lead
(SnPb 60/40)
Bath temperature 215 °C
Soldering time 3 s
Bath temperature 260 °C
Soldering time 10 s
b) Solder reflow method according to IEC 60068-2-58
Applicable for chip-style SMD components. Reflow temperature profile is stated in
IEC 60068-2-58, 8.1.2.1 for wetting test and 8.1.2.2 for resistance to soldering heat test.
Wetting test
Resistance to
soldering heat
Lead-free solder
(Sn96.5Ag3Cu0.5)
Peak temperature 225 ... 235 °C
Duration maximum 20 s
Peak temperature 245 ... 255 °C
Duration maximum 20 s
Please read Cautions and warnings and
Important notes at the end of this document.
Solder containing lead
(SnPb 60/40)
Peak temperature 215 °C
Duration maximum 10 s
Peak temperature 235 °C
Duration maximum 30 s
Page 21 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
1.3.3
Superior series
Placement and orientation of SMDs on PCB
a) Component placement
It is recommended that the PC board
should be held by means of some
adequate supporting pins such as
shown left to prevent the SMDs from
being damaged or cracked.
b) Cracks
When placing a component near an
area which is apt to bend or a grid
groove on the PC board, it is advisable
to have both electrodes subjected to
uniform stress, or to position the
component's electrodes at right angles
to the grid groove or bending line.
c) Component orientation
Choose a mounting position that
minimizes the stress imposed on the
chip during flexing or bending of the
board.
Please read Cautions and warnings and
Important notes at the end of this document.
Page 22 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
1.4
Soldering profiles
1.4.1
Wave soldering
Superior series
Recommended temperature profile for wave soldering following IEC 61760-1. Applicable for leaded PTCs and selected SMD PTCs (case sizes 3225 and 4032 as well as superior series for case
sizes 0402, 0603 and 0805 limit temperature sensors).
Please read Cautions and warnings and
Important notes at the end of this document.
Page 23 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
1.4.2
Superior series
Reflow soldering
Recommended temperature characteristic for reflow soldering following JEDEC J-STD-020D
Profile feature
Preheat and soak
- Temperature min
- Temperature max
- Time
Average ramp-up rate
Liquidous temperature
Time at liquidous
Peak package body temperature
Time (tP)3) within 5 °C of specified
classification temperature (Tc)
Average ramp-down rate
Time 25 °C to peak temperature
Tsmin
Tsmax
tsmin to tsmax
Tsmax to Tp
TL
tL
Tp1)
Tp to Tsmax
Sn-Pb eutectic assembly
Pb-free assembly
100 °C
150 °C
60 ... 120 s
3 °C/ s max.
183 °C
60 ... 150 s
220 °C ... 235 °C2)
150 °C
200 °C
60 ... 180 s
3 °C/ s max.
217 °C
60 ... 150 s
245 °C ... 260 °C2)
20 s3)
30 s3)
6 °C/ s max.
maximum 6 min
6 °C/ s max.
maximum 8 min
1) Tolerance for peak profile temperature (TP) is defined as a supplier minimum and a user maximum.
2) Depending on package thickness. For details please refer to JEDEC J-STD-020D.
3) Tolerance for time at peak profile temperature (tP) is defined as a supplier minimum and a user maximum.
Note: All temperatures refer to topside of the package, measured on the package body surface.
Number of reflow cycles: 3
Please read Cautions and warnings and
Important notes at the end of this document.
Page 24 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Superior series
1.4.3
Solder joint profiles for PTC theristors with chrome/nickel/tin terminations
2
Storage of PTC thermistors
PTC thermistors should be soldered after shipment from EPCOS within the time specified:
Use thermistor within the following period after delivery:
Through-hole devices (housed and leaded PTCs)
Motor protection sensors, glass-encapsulated sensors and probe assemblies
Telecom pair and quattro protectors (TPP, TQP)
Leadless PTC thermistors for pressure contacting
Leadless PTC thermistors for soldering
SMDs in EIA sizes 3225 and 4032, and for PTCs with metal tags
SMDs in EIA sizes 0402, 0603, 0805 and 1210
24 months
24 months
24 months
12 months
6 months
24 months
12 months
The parts are to be left in the original packing.
Storage temperature:
Relative humidity:
25 ... + 45 °C
≤ 75% annual average, ≤ 95% on 30 days in a year
The solderability of the external electrodes may be deteriorated if SMDs are stored where they
are exposed to high humidity, dust or harmful gas (hydrogen chloride, sulfuric acid gas or hydrogen sulfide).
Please read Cautions and warnings and
Important notes at the end of this document.
Page 25 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Superior series
Do not store SMDs where they are exposed to heat or direct sunlight. Otherwise, the packing material may be deformed or SMDs may stick together, causing problems during mounting.
After opening the factory seals, such as polyvinyl-sealed packages, it is recommended to use the
components as soon as possible.
3
Conductive adhesion
An alternative to soldering is the gluing of thermistors with conductive adhesives. The benfit of
this method is that it involves no thermal stress. The adhesives used must be chemically inert and
suitable for the temperatures arising at the surface of the termistor.
4
Clamp contacting
Pressure contacting by springs is required for applications involving frequent switching and high
turn-on powers. Soldering is not allowed for such applications in order to avoid operational failure
in the long term. PTC thermistors for heating and motor starting have metallized surfaces for
clamp contacting.
5
Robustness of terminations
The leads meet the requirements of IEC 60068-2-21. They may not be bent closer than 4 mm
from the solder joint on the thermistor body or from the point at which they leave the
feedthroughs. During bending, any mechanical stress at the outlet of the leads must be removed.
The bending radius should be at least 0.75 mm.
Tensile strength:
Test Ua1:
Leads
∅ ≤ 0.5 mm = 5 N
∅ > 0.5 mm = 10 N
Bending strength: Test Ub:
Two 90°-bends in opposite directions at a weight of 0.25 kg.
Torsional strength: Test Uc: severity 2
The lead is bent by 90° at a distance of 6 to 6.5 mm from the thermistor body.
The bending radius of the leads should be approx. 0.75 mm. Two torsions of
180° each (severity 2).
Please read Cautions and warnings and
Important notes at the end of this document.
Page 26 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Superior series
When subjecting leads to mechanical stress, the following should be observed:
Tensile stress on leads
During mounting and operation tensile forces on the leads are to be avoided.
Bending of leads
Bending of the leads directly on the thermistor body is not permissible.
A lead may be bent at a minimum distance of twice the wire's diameter +2 mm from the solder
joint on the thermistor body. During bending the wire must be mechanically relieved at its outlet.
The bending radius should be at least 0.75 mm.
Twisting of leads
The twisting (torsion) by 180° of a lead bent by 90° is permissible at 6 mm from the bottom of the
thermistor body.
6
Sealing and potting
When thermistors are sealed or potted, there must be no mechanical stress through differing thermal expansion in the curing process and during later operation. In the curing process the upper
category temperature of the thermistor must not be exceeded. It is also necessary to ensure that
the potting compound is chemically inert.
Sealing and potting compounds may degenerate the titanate ceramic of PTC thermistors and lead
to the formation of low-ohmic conduction bridges. In conjunction with a change in dissipation conditions due to the potting compound, local overheating may finally damage the thermistor.
Therefore sealing and potting should be avoided whenever possible.
7
Cleaning
You may use common cleaners based on organic solvents (eg dowanol or alcohol) to clean ceramic and solder joints.
For sufficient cleaning flux must be completely removed.
Solvents may cause plastic encapsulations to swell or detach. So be sure to check the suitability
of a solvent before using it.
Caution is required with ultrasonic processes. If the sound power is too high, for example, it can
degrade the adhesive strength of the terminal metallization or couse the encapsulation to detach.
After cleaning drying is promptly necessary.
Please read Cautions and warnings and
Important notes at the end of this document.
Page 27 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Superior series
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 thermistors 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 humidity ≤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 operation (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.
Please read Cautions and warnings and
Important notes at the end of this document.
Page 28 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Superior series
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. Especially 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 atmospheric conditions. Avoid use in deoxidizing gases (chlorine gas, hydrogen sulfide gas, ammonia 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).
Please read Cautions and warnings and
Important notes at the end of this document.
Page 29 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
Symbols and terms
A
Cth
f
I
Imax
IR
IPTC
Ir
Ir,oil
Ir,air
IRMS
IS
ISmax
LCT
N
Nc
Nf
P
P25
Pel
Pdiss
RG
Rmin
RR
∆RR
RP
RPTC
Rref
RS
R25
R25,match
∆R25
T
t
TA
ta
TC
Area
Heat capacity
Frequency
Current
Maximum current
Rated current
PTC current
Residual currrent
Residual currrent in oil (for level sensors)
Residual currrent in air (for level sensors)
Root-mean-square value of current
Switching current
Maximum switching current
Lower category temperature
Number (integer)
Operating cycles at Vmax, charging of capacitor
Switching cycles at Vmax, failure mode
Power
Maximum power at 25 °C
Electrical power
Dissipation power
Generator internal resistance
Minimum resistance
Rated resistance
Tolerance of RR
Parallel resistance
PTC resistance
Reference resistance
Series resistance
Resistance at 25 °C
Resistance matching per reel/ packing unit at 25 °C
Tolerance of R25
Temperature
Time
Ambient temperature
Thermal threshold time
Ferroelectric Curie temperature
Please read Cautions and warnings and
Important notes at the end of this document.
Page 30 of 32
Sensors
Limit temperature sensors, EIA sizes 0402, 0603 and 0805
tE
TR
Tsense
Top
TPTC
tR
Tref
TRmin
tS
Tsurf
UCT
V or Vel
VRMS
VBD
Vins
Vlink,max
Vmax
Vmax,dyn
Vmeas
Vmeas,max
VR
VPTC
Settling time (for level sensors)
Rated temperature
Sensing temperature
Operating temperature
PTC temperature
Response time
Reference temperature
Temperature at minimum resistance
Switching time
Surface temperature
Upper category temperature
Voltage (with subscript only for distinction from volume)
Root-mean-square value of voltage
Breakdown voltage
Insulation test voltage
Maximum link voltage
Maximum operating voltage
Maximum dynamic (short-time) operating voltage
Measuring voltage
Maximum measuring voltage
Rated voltage
Voltage drop across a PTC thermistor
α
∆
δth
τth
λ
Temperature coefficient
Tolerance, change
Dissipation factor
Thermal cooling time constant
Failure 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.
Please read Cautions and warnings and
Important notes at the end of this document.
Page 31 of 32
Important notes
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 requirements 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 incumbent on the customer to check and decide whether an EPCOS product with the properties described 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 Material Data Sheets on the Internet (www.epcos.com/material). Should you have any more detailed 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 foregoing for customer-specific products.
6. Unless otherwise agreed in individual contracts, all orders are subject to the current version of the "General Terms of Delivery for Products and Services in the Electrical Industry" published by the German Electrical and Electronics Industry Association
(ZVEI).
7. The trade names EPCOS, BAOKE, Alu-X, CeraDiode, CSMP, CSSP, CTVS, DeltaCap,
DigiSiMic, DSSP, FormFit, MiniBlue, MiniCell, MKK, MKD, MLSC, MotorCap, PCC,
PhaseCap, PhaseCube, PhaseMod, PhiCap, SIFERRIT, SIFI, SIKOREL, SilverCap,
SIMDAD, SiMic, 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.
Page 32 of 32
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