Ro VE LEA HS RS D CO I O N F R E M SA E PL R IA E NT * Features ■ ■ ■ ■ Lead free versions available (RoHS compliant*) Overvoltage/lightning protection to Bellcore GR-1089 & ITU-T K.20 Standard “off the shelf” designs Typical application is secondary protection on telecom line cards ■ Custom versions available, including SMD solutions and fuse technology (contact factory) 4B04B-50X-RC - Surge Line Protection Modules 4B04B-501 (Pair of Matched Resistors) 4B04B-502 (Resistor with Thermal Fuse) Product Characteristics Resistance Values ........................................20 ohms - 100 ohms Resistance Tolerance ...........................................................±1 % TCR............................................................................100 ppm/°C Ratio Tolerance.......................................>34 ohms...........±0.5 % <34 ohms..............±1 % Power Dissipation (per resistor) @ 25 ºC ................................2 W Temperature Range ..........................................-55 ºC to +125 ºC Product Characteristics Resistance Values.......................................5.6 ohms - 100 ohms Resistance Tolerance....................1 % (optional), 5 % (standard) TCR ..................................................................800 ±200 ppm/°C Power Dissipation @ 25 ºC.....................................................2 W Temperature Range..........................................-55 ºC to +125 ºC Environmental Characteristics TESTS PER MIL-STD-202 ..............................................∆R MAX. Resistance to Solvents .........................No Marking Deterioration Resistance to Solder Heat ...........................±0.5 % or 0.5 ohms, whichever is greater Solderability .......................................................>95 % Coverage Insulation Resistance ................10 megohms min. (isolated pins) Bias Humidity Test .......................................50 V/85 % RH/85 °C 10 x 1000 µsec ..................1 kV 2 x 10 µsec .....................2.5 kV Power Cross Test ............................................Per Bellcore spec. (Vrms applied vary with resistance values) Functional Characteristics Lightning Surge Test Bellcore Spec GR-1089 Functional Characteristics Lightning Surge Test Bellcore Spec GR-1089 Physical Characteristics Body Style ..........................................................Open Frame SIP Body Material .........................................................96 % Alumina Lead Frame Material .................................Copper, solder coated Standard Parts Available Off the Shelf .....................................................5.6 ohms, 10 ohms, 34 ohms 10 x 1000 µsec .................1 kV 2 x 10 µsec ....................2.5 kV ITU-T K.20 10 x 700 µsec ...................2 kV Power Cross Test .............................................Per Bellcore spec. (Vrms applied vary with resistance values) Physical Characteristics Body Style ..........................................................Open Frame SIP Body Material..........................................................96 % Alumina Lead Frame Material..................................Copper, solder coated Standard Parts Available Off the Shelf ..........50 ohms, 100 ohms 1 15.24 (0.600) 15.24 7 (0.600) 11.30 (0.445) 3.43 ± 0.38 (0.135 ± 0.015) 1 2 13 15.24 (0.600) 19 3 4 17.78±.254 (0.700±.010) 2.54±.127 (.100±.005) 0.36 Max. (.014 Max.) 1.40 Max. TYP. (.055 Max.) 12.70 MAX. (0.500) 2.29 Max. (.090 Max.) 15.24 TYP. (0.600) MAX. 2.54±.127 (.100±.005) 50.80 (2.000) 3.05 Max. (.120 Max.) 25.40±.50 (1.000±.020) Functional Schematic Governing dimensions are in mm. Dimensions in parenthesis are inches and are approximate. 0.36 Max. (.014 Max.) User must short pins 3 & 4 on the circuit board How To Order 4B 04 B - 50X - XXX LF Model (4B = Open Frame) Number of Pins Physical Configuration Electrical Configuration • 501 = Pair of Matched Resistors Resistance Code • First 2 digits are significant • Third digit represents the number of zeros to follow Lead Free Option Blank = Standard Product LF = Lead Free / RoHS Compliant Product *RoHS Directive 2002/95/EC Jan 27 2003 including Annex. Specifications are subject to change without notice. Customers should verify actual device performance in their specific applications. How To Order 4B 04 B - 50X - XXX J LF Model (4B = Open Frame) Number of Pins Physical Configuration Electrical Configuration • 502 = Resistor with Thermal Fuse Resistance Code • First 2 digits are significant • Third digit represents the number of zeros to follow 5% Tolerance Lead Free Option Blank = Standard Product LF = Lead Free / RoHS Compliant Product 4B04B-50X-RC - Surge Line Protection Modules 100 90 VOLTAGE IN PERCENT OF PEAK VALUE General Description Surge is defined as a high-energy, short-duration pulse caused by lightning or the switching of power loads. In short, a surge can be a transient wave of voltage, current or power. Most of the surge pulse waveforms are unidirectional impulses. Surge waveforms occur in many situations, including computer memory drivers and telecommunication equipment. Standards for various natural surge pulse waveforms in the telecommunication industry are IEC 801-5, ANSI/IEEE C62.41 and Bellcore GR-NWT001089. Two consequences of inefficient surge protection in a system are (1) permanent damage to internal components, which will require component replacement and (2) temporary instability to a system, resulting in volatile memory loss in a computer or other disruptions. A typical telecommunication application is shown in Figure 1. There are various protection devices which guard against surge overstresses. Typically, a crowbar is used for primary protection, while current limiters and clamps are used as secondary protection. IMPULSE WAVE (ANSI / IEEE C62.41 - 1991) DURATION Td 50 FRONT TIME: 1.67 x (t90-t30) (VOLTAGE) DURATION: t50-t0 30 0 t0 t30 t90 t50 TIME t FOR EXAMPLE: 10X1000 µSEC WAVE FORM DEFINITION OPEN-CIRCUIT VOLTAGE: FRONT TIME: 10 µSEC DURATION: 1000 µSEC Figure 2. Surge Waveform Building Entrance Primary Protection Crowbar (Diverter or Arrestor) on Equipment Line Protection Networks Line protection networks are used to dissipate high energy for a short period of time. Figure 3 shows how the amount of energy is dependent on the pulse duration and value of the load resistance. An equation used to determine the amount of energy transferred to the load by the overstress test waveform can be given as follows1: Secondary Protection Current Limiter (Suppression) Line Protection Network Clamp (Diverter or Arrestor) Fuse Tip Over Voltage Ring 1 RL Energy, W = ________ • ________ (RS + RL) (RS + RL) Figure 1. Typical Telecom Application There are several standard telecommunication waveforms - 10 x 1000 microsecond, 0.5 x 700 micro-second, 10 x 700 microsecond, etc. The definition of a 10 x 1000 microsecond is shown in Figure 2. The first number refers to the voltage rise time while the second numbers indicate the duration. All of these surge pulse waveforms consist of energy levels from 10 to 100 Joules. RS v(t) where RS = source resistance (W) RL = load resistance (W) W = energy (Joules) Specifications are subject to change without notice. Customers should verify actual device performance in their specific applications. RL 8 TELECOM CIRCUIT 2 ∫ v (t)dt 0 Over Voltage 4B04B-50X-RC - Surge Line Protection Modules 12 11 (EXAMPLE: LOAD RESISTOR = 50Ω) 10 9 8 10.0 ENERGY 7 (JOULES) 6 5 4 3 2 Bourns Line Protection Networks The Bourns Line Protection Network provides current limiting for telecommunication protection circuits and consists of two high-power surge resistors, which are utilized in the secondary protection block of central office switch systems (Figure 6). This device protects sensitive circuitry from lightning strikes and power cross-conditions by limiting irregular currents through the system. 3.4 1 10 x 1000 µSEC 1 kV Rs = 10Ω (BELLCORE GR-NWT-001089 SPEC) 10 x 700 µSEC 1 kV Rs = 40Ω (IEC 801-5 SPEC) Figure 3. Energy Comparison Surge protection is necessary in situations where smaller device geometries and higher densities make circuits susceptible to electrical over stress. Applications include instances where faster processing speeds having less inherent filtering make circuits more susceptible to noise. Also, when vulnerable ICs are used in less-controlled environments, circuits can be exposed to extreme electrical conditions. Common Surge Modes There are two common surge modes: (1) metallic, i.e., normal, transverse or differential (Figure 4) and (2) longitudinal, i.e., common (Figure 5). In the metallic surge mode, earth or ground is not involved. Both conductors are metal. Surge current flows from tip to ring or ring to tip. The longitudinal surge mode involves a connection in which the wave is applied between one or more lines and ground. The longitudinal surge current flows from tip to ground and ring to ground. Power Lines CENTRAL OFFICE Telephone Line Primary Protection Secondary Protection SLIC Figure 6. Surge Causes The line protection network features a resistance range between 50 and 100 ohms, resistors that are able to withstand lightning and power conditions per Bellcore specification GRNWT-001089, noise reduction through close-ratio matching (± percent) between tip and ring resistor pairs and superior material systems created especially for high-power, high-reliability products and applications. Tip Ring TELECOM CIRCUIT G Figure 4. Typical Metallic Application Mode Tip Ring TELECOM CIRCUIT G Figure 5. Typical Longitudinal Application Mode Specifications are subject to change without notice. Customers should verify actual device performance in their specific applications. 4B04B-50X-RC - Surge Line Protection Modules Thick Film Line Protection Network Technology Comparison ELEMENTS OLDER TECHNOLOGY Ceramic thickness Greater than 0.040 in. Less than or equal to 0.040 in. Seated height Greater than 0.5 in. Less than or equal to 0.5 in. Thick Film Line Protection Network Construction And Benefits CROSS-SECTION OF TYPICAL DESIGN STATE-OF-THE-ART TECHNOLOGY Glaze (Environmental Passivation) Thick Film Resistor (High Power Material) Solder Attached (Excellent in Pullstrength) Material and process Standard thick film material and process • New high power material • Improved processing Temperature coefficient of resistance (TCR) Greater than 100ppm/°C Less than 100ppm/°C Tip and ring resistors ratio 1% 0.5% or lower 10 x 700 µsec 1 kV 10 x 1000 µsec 1 kV 10 x 700 µsec 1 kV 10 x 1000 µsec 1 kV 2 x 10 µsec 2.5 kV 2% or greater 0.25% or lower Surge test waveforms • 100 cycles • 100 cycles • 10 cycles Bias humidity temperature 1000 hr. ∆R Termination (Heat Conductivity, Good Solderability) Ceramic Substrate Lead Frame (Excellent Thermal Conductivity, Pull Strength) Customer Advantages The Bourns Thick Film Line Protection Network provides customers with tip and ring resistors on the same component for single placement processing. Customer lead times are reduced because parts are readily available. Bourns is an experienced supplier of state-of-the-art thick film overcurrent protection devices. Bourns also has global design and manufacturing centers for localized service. Specialty devices are available like surge resistor and standard resistors on the same package, fusible links which are “fail safe” integrated with surge resistors and custom electrical configurations and tolerances. The thick film line protection network also has quick-turn sample times. 1 REFERENCE: STANDLER, RONALD B., “PROTECTION OF ELECTRONIC CIRCUITS FROM OVERVOLTAGES.” PP 89 - 102, 1989. REV. 02/07 Specifications are subject to change without notice. Customers should verify actual device performance in their specific applications.