SIST EN 140401-802:2008
(Main)Detail specification: Fixed low power film SMD resistors - Rectangular - Stability classes 1; 2
Detail specification: Fixed low power film SMD resistors - Rectangular - Stability classes 1; 2
Various parameters of this component are precisely specified in this specification.Unspecified parameters may vary from one component to another.
Bauartspezifikation: SMD Schicht-Festwiderstände niedriger Belastbarkeit - Rechteckig - Stabilitätsklassen 1; 2
Spécification particulière: Résistances couche fixes à faible dissipation CMS - Rectangulaires - Catégories de stabilité 1; 2
Podrobna specifikacija: Fiksni folijski upori majhnih moči za površinsko montažo - Pravokotni - Razreda stabilnosti 1; 2
Različni parametri te komponente so natančno določeni v tej specifikaciji. Nedoločeni parametri se lahko razlikujejo med komponentami.
General Information
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Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Detail specification: Fixed low power film SMD resistors - Rectangular - Stability classes 1; 2Spécification particuliere: Résistances couche fixes a faible dissipation CMS - Rectangulaires - Catégories de stabilité 1; 2Bauartspezifikation: SMD Schicht-Festwiderstände niedriger Belastbarkeit - Rechteckig - Stabilitätsklassen 1; 2Ta slovenski standard je istoveten z:EN 140401-802:2007SIST EN 140401-802:2008en31.040.10Fiksni uporFixed resistorsICS:SIST EN 140401-802:2003/A1:2004SIST EN 140401-802:20031DGRPHãþDSLOVENSKI
STANDARDSIST EN 140401-802:200801-januar-2008
EUROPEAN STANDARD EN 140401-802 NORME EUROPÉENNE
EUROPÄISCHE NORM September 2007
CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2007 CENELEC -
All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 140401-802:2007 E
ICS 31.040.10 Supersedes EN 140401-802:2002 + A1:2004
English version
Detail specification:
Fixed low power film SMD resistors -
Rectangular -
Stability classes 1; 2
Spécification particulière:
Résistances couche fixes
à faible dissipation CMS -
Rectangulaires -
Catégories de stabilité 1; 2
Bauartspezifikation:
SMD Schicht-Festwiderstände
niedriger Belastbarkeit -
Rechteckig -
Stabilitätsklassen 1; 2
This European Standard was approved by CENELEC on 2007-05-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom.
EN 140401-802:2007 – 2 – Foreword This European Standard was prepared by the Technical Committee CENELEC TC 40XB, Resistors. The text of the draft was submitted to the Unique Acceptance Procedure and was approved by CENELEC as EN 140401-802 on 2007-05-01. This European Standard supersedes EN 140401-802:2002 + A1:2004. Preceding documents on the subject covered by this specification have been – CECC 40 401-802:1998, only on resistors without established reliability, now version A – CECC 40 401-002:1993, – CECC 40 401-004:1984; 1985; 1990; 1992, – CECC 40 401-007:1989; 1990; 1992, only on resistors with established reliability, now version E – CECC 40 401-006:1989; 1991; 1993. Compared to the superseded standard, the following changes have been implemented: – modification of the title; – introduction of a test on the resistance to electrostatic discharge in 1.6 and Annex A; – introduction of description and test methods for lead-free soldering in 1.8, 1.10.3 and Annex A; – introduction of the code letters for temperature coefficient as given in EN 60062; – revision of the ordering information in 1.9.4; – revised information on pulse load capability in 1.10.6; – revised information on resistance value drift in 1.10.7; – revised information on current noise in 1.10.9; – adoption of the IECQ rules of procedure, QC 001002-3; – revision of the sample quantities and the sequence of tests in Annex A; – editorial revision. The following dates were fixed: – latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement
(dop)
2008-05-01 – latest date by which the national standards conflicting
with the EN have to be withdrawn
(dow)
2010-05-01 This specification is part of four documents describing fixed resistors for surface mount technology as follows: EN 60115-1 Fixed resistors for use in electronic equipment - Part 1: Generic specification
(IEC 60115-1, mod.) EN 140400 Sectional specification: Fixed low power surface mount (SMD) resistors EN 140401 Blank Detail Specification: Fixed low power non wire-wound surface mount (SMD) resistors EN 140401-802 Detail specification: Fixed low power film SMD resistors - Rectangular - Stability classes
1; 2 __________
– 3 – EN 140401-802:2007 Table of contents 1 Characteristics and ratings.4 1.1 Dimensions and ratings.4 1.2 Derating curve.5 1.3 Resistance range and tolerance on rated resistance.6 1.3.1 Version A.6 1.3.2 Version E.6 1.4 Variation of resistance with temperature and temperature rise.7 1.5 Climatic categories.8 1.6 Limits for change of resistance at tests.8 1.7 Non-linear properties.9 1.8 Tests related to soldering.9 1.8.1 Severities for solderability testing.9 1.8.2 Severities for testing resistance to soldering heat.10 1.9 Marking, packaging and ordering designation.10 1.9.1 Marking of the component.10 1.9.2 Taping.10 1.9.3 Marking of the packaging.10 1.9.4 Ordering information.11 1.10 Additional information (not for inspection purpose).11 1.10.1 Storage.11 1.10.2 Mounting.11 1.10.3 Soldering process.11 1.10.4 Conductive gluing.12 1.10.5 Use of cleaning solvents.12 1.10.6 Pulse load capability.12 1.10.7 Variation of resistance value (drift) for operating times up to 200 000 h.15 1.10.8 Dissipation notes.16 1.10.9 Current noise.17 1.10.10 Temperature range extension.17 2 Quality assessment procedures.18 2.1 General.18 2.1.1 Zero defect approach.18 2.1.2 100 %-test.18 2.1.3 0 Ω Resistor.19 2.1.4 Certificate of Conformity (CoC).19 2.1.5 Certified test records.19 2.1.6 Failure rate level.19 2.2 Qualification approval.19 2.2.1 Version A.19 2.2.2 Version E.19 2.3 Quality conformance inspection.20 2.3.1 Qualification approval according to QC 001002-3, Clause 3.20 2.3.2 Technology approval according to QC 001002-3, Clause 6.20 2.3.3 Non-conforming items.20 Annex A (normative)
Fixed sample size Qualification Approval and Quality Conformance Inspection
test schedule for fixed low power surface mount (SMD) resistors.21 Annex B (informative)
Letter symbols and abbreviations.28 Bibliography.30
EN 140401-802:2007 – 4 – Specification available from the National Committees members of CENELEC EN 140401-802
Electronic components of assessed quality in accordance with EN 60115-1:2001 + A1:2001 EN 140400:2003 EN 140401:2002
Fixed low power film chip resistors with rectangular base for surface mounting. Style: RR Ceramic substrate with protected, insulated, resistance film (thick film) and solder terminations
Other shapes are permitted within the given dimensions. Figure 1 – Outline and dimensions (see Table 1)
Assessment level EZ a Version A: with 100- %-test Version E: with failure rate level
and 100- %-test Stability classes 1 and 2 a For explanations on assessment level EZ see 2.1.1. 1 Characteristics and ratings Various parameters of this component are precisely specified in this specification. Unspecified parameters may vary from one component to another. 1.1 Dimensions and ratings
Table 1 – Style and dimensions Style Length L mm Width W mm Height H mm Termination T mm Massa mg metric inch min. Max. Min. Max. Min. Max. Min. Max. Max. RR 1005M RR 0402 0,95 1,10 0,45 0,60 0,25 0,40 0,10 0,35 0,8 RR 1608M RR 0603 1,50 1,70 0,75 0,95 0,35 0,55 0,10 0,50 2,1 RR 2012M RR 0805 1,85 2,15 1,10 1,40 0,35 0,65 0,15 0,60 6,0 RR 3216M RR 1206 2,90 3,35 1,45 1,75 0,35 0,65 0,25 0,75 10,0 RR 5025M RR 2010 4,80 5,20 2,30 2,70 0,35 0,75 0,35 0,85 30,0 a For information only. Termination: WT ≥ 0,75 · W Thickness: 0,005 mm to 0,05 mm.
Information about manufacturers who have components qualified to this detail specification is available in the approvals section of the website http://www.iecq.org
– 5 – EN 140401-802:2007 Table 2a – Ratings for stability classes 2 and 1 Style Rated dissipation P70 mW Limiting element voltage d.c. or a.c. (r.m.s.) Umax V Insulation voltage d.c. or a.c. (peak) Uins V
1 min continuous RR 1005M 63 50 75 75 RR 1608M 100 75 100 75 RR 2012M 125 150 200 75 RR 3216M 250 200 300 75 RR 5025M 500 300 300 75
Table 2b – Ratings for 0 Ω resistors Style Maximum current Imax A Maximum resistance valuea Rmax mΩ Insulation voltage d.c. or a.c. (peak) Uins V
1 min continuous RR 1005M
0,63 20 75 75 RR 1608M 1,0 20 100 75 RR 2012M 1,5 20 200 75 RR 3216M 2,0 20 300 75 RR 5025M 3,0 20 300 75 a
The resistance value shall be measured on the film side.
1.2 Derating curve Resistors covered by this specification are derated according to the following diagram: Ambient temperature ϑaPercentage of rated dissipation-50 °C100 °C50 °C0 °C150 °C0 %60 %40 %20 %100 %80 %70 °C-55 °C125 °CLower category temperature (LCT)Upper category temperature (UCT)-100 °C200 °CStability class 2; 1 Figure 2 – Derating curve
EN 140401-802:2007 – 6 – 1.3 Resistance range and tolerance on rated resistance 1.3.1 Version A The following combinations of temperature coefficient and tolerance on rated resistance may be approved only. Products from this extent shall be used for the qualification approval according to 2.2.1 and for the quality conformance inspection according to 2.3. Resistance values of an E-series according to IEC 60063 shall be used.
The qualification of resistance values below or beyond the specified resistance values is permitted, if they fulfil the requirements of the closest stability class (e.g. RR 1608M 1 % > 1 MΩ shall fulfil the requirements of stability class 1). Table 3a – Resistance range, tolerance on rated resistance for version A Style Tolerance on rated resistance Temperature coefficient Resistance range Stability class
% Code a ppm/K
RR 1005M ± 5 J ± 200 1 Ω to 6,8 MΩ 2
± 2 G ± 100 10 Ω to 1 MΩ 2
± 1 F ± 100; ± 50 10 Ω to 1 MΩ 1 RR 1608M ± 5 J ± 200 1 Ω to 6,8 MΩ 2
± 2 G ± 100 10 Ω to 1 MΩ 2
± 1 F ± 100; ± 50 10 Ω to 1 MΩ 1 RR 2012M ± 5 J ± 200 1 Ω to 10 MΩ 2
± 2 G ± 100 10 Ω to 1 MΩ 2
± 1 F ± 100; ± 50 10 Ω to 1 MΩ 1 RR 3216M ± 5 J ± 200 1 Ω to 10 MΩ 2
± 2 G ± 100 10 Ω to 1 MΩ 2
± 1 F ± 100; ± 50 10 Ω to 1 MΩ 1 RR 5025M ± 5 J ± 200 1 Ω to 10 MΩ 2
± 2 G ± 100 10 Ω to 1 MΩ 2
± 1 F ± 100 ; ± 50 10 Ω to 1 MΩ 1 0 Ω-resistors according to Table 2b for all styles. a
Code letters according to EN 60062.
1.3.2 Version E The following combinations of temperature coefficient, tolerance on rated resistance, resistance range and
E-series according to IEC 60063 are permitted only. Products from this extent shall be used for the qualification approval according to 2.2.2 and for the quality conformance inspection according to 2.3.
– 7 – EN 140401-802:2007 Table 3b – Resistance range, tolerance on rated resistance for version E Style Tolerance on rated resistance Temperature coefficient Resistance range Stability class E series
% Code a ppm/K
RR 1005M ± 5 J ± 200 1 Ω to 6,8 MΩ 2 E24
± 1 F ± 100 100 Ω to 33,2 kΩ 1 E96 RR 1608M ± 5 J ± 200 1 Ω to 6,8 MΩ 2 E24
± 1 F ± 100 10 Ω to 1 MΩ 1 E96 RR 2012M ± 5 J ± 200 1 Ω to 9,1 Ω 2 E24
1,1 MΩ to 10 MΩ 2
± 1 F ± 100 10 Ω to 1 MΩ 1 E96
± 50 10 Ω to 1 MΩ 1
RR 3116M ± 5 J ± 200 1 Ω to 9,1 Ω 2 E24
1,1 MΩ to 10 MΩ 2
± 1 F ± 100 10 Ω to 1 MΩ 1 E96
± 50 10 Ω to 1 MΩ 1
RR 5025M ± 5 J ± 200 1 Ω to 9,1 Ω 2 E24
1,1 MΩ to 10 MΩ 2
± 1 F ± 100 10 Ω to 1 MΩ 1 E96
± 50 10 Ω to 1 MΩ 1
0 Ω-resistors according to Table 2b for all styles. a
Code letters according to EN 60062.
1.4 Variation of resistance with temperature and temperature rise Table 4 – Temperature coefficients and limits of resistance change
Temperature coefficient Limit of resistance change ∆R/R %
ppm/K Codea Codeb LCT / Reference temp. °C Reference temp. / UCT °C
-55 / 20 20 / 125 ± 200 Uc A ± 1,5 ± 2,1 ± 100 S B ± 0,75 ± 1,05 ± 50 R C ± 0,375 ± 0,525 a Code letters according to EN 60062. b Historical code letters according to EN 140400, for information only. c Tightening of the definition of code letter U (EN 60062: U = 250 ppm/K).
EN 140401-802:2007 – 8 – Table 5 – Limit of temperature rise Stability class Limit of temperature rise at rated dissipation 2; 1 Tr ≤ 55 K
1.5 Climatic categories Table 6 – Climatic categories Stability class Climatic category LCT / UCT / Duration 2; 1 55 / 125 / 56
1.6 Limits for change of resistance at tests Table 7a – Limits for change of resistance at tests Limit of resistance change ∆R EN 60115-1, 4.25.1 Endurance at 70 °C
Stability class EN 60115-1, 4.23 Climatic
sequence 4.24 Damp heat,
steady state 4.25.3 Endurance at
upper
category
temperature 1 000 h Extended, 8 000 h EN 60115-1, 4.13 Overload 4.18 Resistance to
soldering heat 4.19 Rapid change
of temperature,
5 cycles 4.22 Vibration 4.33 Substrate
bending 2 ± (2 % R + 0,1 Ω) ± (2 % R + 0,1 Ω) ± (4 % R + 0,1 Ω) a ± (0,5 % R + 0,05 Ω) 1 ± (1 % R + 0,05 Ω) ± (0,5 % R + 0,05 Ω) a ± (1 % R + 0,05 Ω) a ± (0,25 % R + 0,05 Ω) a Tightening of the general definition of stability classes against the requirements of EN 140400, 2.1.4.
Table 7b – Limits for change of resistance at tests
Limit of resistance change ∆R Stability class EN 60115-1, 4.19 Rapid change
of temperature, 1 000 cycles EN 60115-1, 4.27 Single pulse
high voltage
overload test EN 60115-1, 4.27 Periodic
electric
overload EN 60115-1, 4.40 Electrostatic discharge a 2 1 ± (1 % R + 0,05 Ω) ± (1 % R + 0,05 Ω) ± (1 % R + 0,05 Ω) ± (1 % R + 0,05 Ω) a Human Body Model (HBM) according to EN 61340-3-1, 3 positive + 3 negative discharges.
– 9 – EN 140401-802:2007 1.7 Non-linear properties If for resistors in the range 10 Ω ≤ R ≤ 10 MΩ measurement of non-linearity is required according to 2.1.2,
the measured values shall be above the limits given in the diagram below. The resistors shall be tested according to IEC/TR 60440 where the test voltage shall be the rated voltage. Resistance value RAttenuation of 3rd Harmonic A310 Ω100 Ω1 kΩ10 kΩ100 kΩ1 MΩ10 MΩ120 dB100 dB80 dB60 dB40 dB20 dB0 dB Figure 3 – Limits of non-linearity in resistors 1.8 Tests related to soldering 1.8.1 Severities for solderability testing To prove the compatibility of resistors according to this specification with lead free solder, e.g. SnCu, SnCuNi, SnAg or SnAgCu, and traditional SnPb solder, solderability shall be tested with both types of solder. a) Solderability with traditional SnPb solder shall be tested according to EN 60068-2-58, 8.2.1, solder bath
method, with the following conditions:
Solder alloy: Sn60Pb40 or Sn63Pb37
Solder bath temperature: (235 ± 5) °C
Immersion time: (2 ± 0,2) s b) Solderability with lead-free solder shall be tested according to EN 60068-2-58, 8.1.1, solder bath method,
with the following conditions (Group 3):
Solder alloy: Sn96,5Ag3,0Cu0,5
Solder bath temperature: (245 ± 5) °C
Immersion time: (3 ± 0,3) s
or with the following conditions (Group 4):
Solder alloy: Sn99,3Cu0,7
Solder bath temperature: (250 ± 5) °C
Immersion time: (3 ± 0,3) s The categories Group 3 and Group 4 are defined in EN 60068-2-58 for the discrimination of the wide variety of lead-free solder alloys by means of the related typical soldering processes an their specific temperature ranges. Group 3, described as “medium-high temperature”, lists examples of solder alloys SnAg, SnAgCu and SnAgBi, all intended for both reflow and flow (wave) soldering. Group 4, described as “high temperature”, covers SnCu solder, primarily intended for flow (wave) soldering.
EN 140401-802:2007 – 10 – 1.8.2 Severities for testing resistance to soldering heat The severity of the resistance to soldering heat test is determined by the peak temperature and by the temperature slopes before and after the dwell time at the peak temperature. Therefore no separate tests are required for lead free soldering, e.g. SnCu, SnCuNi, SnAg or SnAgCu, and traditional SnPb soldering, if the more severe test condition from those given in EN 60068-2-58 is adopted. For the solder bath method, EN 60068-2-58, 8.1.1 for lead-free soldering, and EN 60068-2-58, 8.2.1 for SnPb soldering require similar test conditions:
Solder alloy: any alloy SnPb or SnCu or SnAgCu or SnAg
Solder bath temperature: (260 ± 5) °C
Immersion time: (10 ± 1) s
Test cycles: one only The solder bath method is the most severe test method, representing the soldering stress of all wave soldering and reflow soldering methods.
Table 8 – Test method for resistance to soldering heat test Stability class Test method for resistance to soldering heat test 2; 1 Solder bath method
1.9 Marking, packaging and ordering designation 1.9.1 Marking of the component Surface mount resistors are generally not marked on the body.
However, if marking is applied to version A resistors, the component shall be marked with the rated resistance using a letter and digit code according to EN 60062, Clause 4, preferably the four-character code according to EN 60062, 4.2.3. For version E resistors, the component shall be marked with the rated resistance using a letter and digit code according to EN 60062, Clause 4, preferably the four-character code according to EN 60062, 4.2.3. The marking of the styles RR 1005M and RR 1608M is not required. Marking of the temperature coefficient and of any other item from the list of EN 60115-1, 2.4.1 shall be the choice of the manufacturer. 1.9.2 Taping Components may be taped or put in a bulk case. For environmental protection packaging into bulk cases is preferred. Taping shall be in accordance with EN 60286-3 type I. Bulk case packaging shall be in accordance with EN 60286-6.
1.9.3 Marking of the packaging The packaging of the component shall be marked with ordering information in accordance to 1.9.4 and additionally with – CECC or IECQ sign of conformity, – CECC or IECQ manufacturer code, – NATO manufacturer code (only version E, if required), – date code of manufacture according to EN 60062.
Additional information is permissible.
– 11 – EN 140401-802:2007 1.9.4 Ordering information Orders for resistors covered by this specification shall contain the following information: – detail specification number; – assessment level; – style; – temperature coefficient; – rated resistance; – tolerance on rated resistance; – failure rate level (only version E); – form of delivery, packaging method (in addition to the ordering information given in the examples below). Example of the ordering information for 150 Ω resistors:
Version A: EN 140401–802EZRR1608MU150RJE0
Version E (with failure rate level): EN 140401–802EZRR1608MU150RJE6 Example of the ordering information for 0 Ω resistors:
Version A: EN 140401–802EZRR1608M–0R00–E0
Version E (with failure rate level): EN 140401–802EZRR1608M–0R00–E6 The elements used in this ordering information have the following meaning:
EN 140401–802 Detail specification number
EZ Assessment level
RR1608M Style (see Table 1)
U Temperature coefficient according to EN 60062 (see Table 4)
150R Resistance value according to EN 60062, 4 characters
J Tolerance on rated resistance (see Table 3a or Table 3b)
E0; E6 Failure rate level according to EN 60115-1:2001 + A1:2001, Table ZB.1
1.10 Additional information (not for inspection purpose) 1.10.1 Storage The permitted storage time is 20 years under the conditions of EN 60115-1, 2.7. Solderability and resistance may be affected by storage. Therefore test of solderability and measurement of resistance is recommended before delivery if the storage time exceeds two years. 1.10.2 Mounting The resistors are suitable for mounting on all common printed boards, ceramic substrates and flexible foils. 1.10.3 Soldering process The resistors are suitable for all soldering methods according to EN 61760-1.
This includes full compatibility with – lead free solder, e.g. SnCu, SnCuNi, SnAg or SnAgCu, – conventional SnPb solder. The immersion time shall not exceed 10 s when the components are immersed in a solder of 260 °C. It is recommended to only use fluxes, which do not require a cleaning process after soldering. Flux residues may be hard to remove, particularly from the space between the resistor and the circuit board or substrate. Flux residues may establish some conductivity in parallel to the assembled resistor and thereby adversely affect the performance of the electronic circuit.
EN 140401-802:2007 – 12 – 1.10.4 Conductive gluing The resistors can be mounted with adhesive suitable for SMD mounting. The required adhesive, the adhesive curing temperature and the curing time has to be agreed between customer and manufacturer. 1.10.5 Use of cleaning solvents For the removal of flux residues the following agents may be used: – alcohol, such as ethanol, propanol, isopropanol or butanol; – aqueous solutions; – deionised water. Reaction time of the agent shall not exceed 5 min. Consultation with the resistor manufacturer is recommended if the use of other cleansing agents is intended. 1.10.6 Pulse load capability 1.10.6.1 General The pulse load capability defines the ability of a resistor to withstand short overloads within the provided working period. The pulse load capability is limited by the maximum pulse load Pi, max and
the maximum pulse voltage Ui, max both depending on a given pulse duration ti. The following conditions shall be considered. 1.10.6.2 Average pulse power The average pulse load P shall not exceed the rated dissipation P70. For resistance values above the critical resistance the rated dissipation is given by the resistance value and the limiting element voltage Umax. The average pulse load is calculated to
∫⋅=21d)(²1pttttuRtP (1)
with ti = t2 – t1. a) Rectangular pulse For rectangular pulses the average pulse load is calculated to:
i2peaki,p1tURtP⋅⋅⋅= (2) b) Exponential pulse For exponential pulses the average pulse load calculates to:
21e2peaki,pτ⋅⋅⋅=URtP (3)
with τe = R⋅C or τe = L/R. Figure 4 provides a further explanation of the pulse parameter.
– 13 – EN 140401-802:2007
Figure 4 – Pulse parameter for rectangular and exponential pulses c) Other pulse shapes Other pulse shape should be converted into a rectangular pulse having the same energy at given peak voltage. 1.10.6.3 Pulse power Pi,max for contiuous pulses The permissible pulse load for continuous pulses as shown in Figure 5 is applicable to resistors R ≥ 10 Ω under the following conditions: – mean dissipation maxPP≤, where Pmax is the dissipation permissible according to Figure 2; – pulse voltage Ui ≤ Ui,max, with Ui,max according to Figure 7. Pulse duration tiPermissible pulse power Pi,maxRR 1005MRR 1608M0,1 W10 W10 µs100 µs1 ms10 ms100 ms1 s10 s1 W100 WRR 2012MRR 3216MRR 5025M Figure 5 – Maximum permissible pulse load Pi, max 1.10.6.4 Pulse power Pi,max for single pulses The permissible pulse load for single pulses as shown in Figure 6 is applicable to resistors R ≥ 10 Ω under the following conditions: – mean dissipation 0→P; – number of pulses n < 1 000; – pulse voltage Ui ≤ Ui,max, with Ui,max according to Figure 7. t P t i t 2 t 1 t Ui Ui, peak Ui, peak0,37 • Ui, peakUi t τ e
EN 140401-802:2007 – 14 – Pulse duration tiPermissible pulse power Pi,maxRR 1005MRR 1608M0,1 W10 W10 µs100 µs1 ms10 ms100 ms1 s10 s1 W100 WRR 2012MRR 3216MRR 5025M Figure 6 – Maximum permissible pulse load Pi, max for single pulses
1.10.6.5 Pulse voltage For high ohmic resistors the pulse load capability is limited by the maximum pulse voltage as shown in Figure 7.
Pulse duration tiPermissible pulse voltage Ui,maxRR 1005MRR 1608MRR 2012M100 V1 000 V10 µs100 µs1 ms10 ms100 ms1 s10 s10 VRR 3216MRR 5025M Figure 7 – Maximum permissible pulse voltage Ui, max
1.10.6.6 Permitted change in resistance at pulse loads The permissible pulse load is determined by the resistance changes as given in Table 7a for the extended endurance test (8 000 h).
– 15 – EN 140401-802:2007 1.10.7 Variation of resistance value (drift) for operating times up to 200 000 h 1.10.7.1 Lifetime assessment Resistors described in this specification do not feature a limited lifetime when operated within the limits defined in this specification.
However, resistance value drift increasing over operating time may lead to a situation where the observed drift exceeds an amount acceptable to a specific application, hence rendering that particular application malfunctioning or inoperational. The predictability of resistance drift may be used to assess a functional lifetime as the time required for the drift to increase to the considered critical amount. This assessment is not only related to the resistor, but strongly depends on the
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