V250LTX4

Metal-Oxide Varistors (MOVs) High Reliability Varistors QPL High Reliability Varistors Description Littelfuse High Reliability Varistors offer the latest in increased product performance, and are available for applications requiring quality and reliability assurance levels consistent with military or other standards (MIL-STD-19500, MIL-STD-202). Additionally, Littelfuse Varistors are inherently radiation hardened compared to Silicon Diode suppressors as illustrated in Figure 1. Littelfuse High-Reliability Varistors involve three categories: 1 Qualified Products List (QPL) MIL-PRF-83530 (4 items presently available) Agency Approvals 2 Littelfuse High Reliability Series TX Equivalents (29 items presently available) • QPL 3 Custom Types Processed to customer-specific requirements - (SCD) or to Standard Military Flow Additional Information Datasheet Resources Samples © 2018 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 08/22/18 Metal-Oxide Varistors (MOVs) High Reliability Varistors 1) DSSC Qualified Parts List (QPL) MIL-PRF-83530 This series of varistors are screened and conditioned in accordance with MIL-PRF-83530. Manufacturing system conforms to MIL-I-45208; MIL-Q-9858. Table 1. MIL-PRF-83530 Ratings and Characteristics Part Number M83530/ Nominal Varistor Voltage (V) Tolerance (%) 1-2000B 1-2200D 1-4300E 1-5100E 200 220 430 510 -/+10 +10, -5 +5, -10 +5, -10 Voltage Rating (V) (RMS) (DC) 130 150 275 320 175 200 369 420 Energy Rating (J) Clamping Voltage at 100A (V) 50 55 100 120 325 360 680 810 Clamping Nearest Capacitance Voltage At Commercial at 1MHz (pF) Peak Current Equivalent Rating (V) 3800 3200 1800 1500 570 650 1200 1450 V130LA20B V150LA20B V275LA40B V320LA40B 2) Littelfuse High Reliability Series TX Equivalents Table 2. Available TX Model Types Model Size Device Mark (See Section 4) Nearest Commercial Equivalent V130LTX2 V130LTX10A V130LTX20B 7mm 14mm 20mm 130TX2 130L10 130TX20 V130LA2 V130LA10A V130LA20A V150LTX2 V150LTX10A V150LTX20B 7mm 14mm 20mm 150L2 150TX10 150L20 V150LA2 V150LA10A V150LA20B V250LTX4 V250LTX20A V250LTX40B 7mm 14mm 20mm 250L4 250L20 250L40 V250LA4 V250LA20A V250LA40B V420LTX20A V420LTX40B 14mm 20mm 420L20 420L40 V420LA20A V420LA40B (See Section 4) Nearest Commercial Equivalent TX Model TX Model Model Size Device Mark V8ZTX1 V8ZTX2 7mm 10mm 8TX1 8TX2 V8ZA1 V8ZA2 V12ZTX1 V12ZTX2 7mm 10mm 12TX1 12TX2 V12ZA1 V12ZA2 V22ZTX1 V22ZTX3 7mm 14mm 22TX1 22TX3 V22ZA1 V22ZA3 V24ZTX50 20mm 24TX50 V24ZA50 V33ZTX1 V33ZTX5 V33ZTX70 7mm 14mm 20mm 33TX1 33TX5 33TX70 V33ZA1 V33ZA5 V33ZA70 V68ZTX2 V68ZTX10 7mm 14mm 68TX2 68TX10 V68ZA2 V68ZA10 V480LTX40A V480LTX80B 14mm 20mm 480L40 480TX80 V480LA40A V480LA80B V82ZTX2 V82ZTX12 7mm 14mm 82TX2 82TX12 V82ZA2 V82ZA12 V510LTX40A V510LTX80B 14mm 20mm 510L40 510L80 V510LA40A V510LA80B The TX Series of varistors are 100% screened and conditioned in accordance with MIL-STD-750. These tests are outlined in table 3 below INSPECTION LOTS FORMED AFTER ASSEMBLY > LOTS PROPOSED FOR TX TYPES > 100% SCREENING REVIEW OF DATA TX PREPARA TION FOR DELIVERY > Table 3. TX Equivalents Series 100% Screening MIL-STD-105 LTPD LEVEL AQL Electrical (Bidirectional) VN(DC), VC (Per Specifications Table) II 0.1 - Dielectric Withstand Voltage MIL–STD–202, Method 301, 2500V Min. at 1.0µADC - - 15 Solderability MIL–STD–202, Method 208, No Aging, Non-Activated - - 15 © 2018 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 08/22/18 > QA ACCEPTANCE SAMPLE PER APPLICABLE DEVICE SPECIFICATION Metal-Oxide Varistors (MOVs) High Reliability Varistors Table 4. Quality Assurance Acceptance Tests Screen High Temperature Life (Stabilization Bake) MIL-STD-750 Method Condition TX Requirements 1032 24 hours min at max rated storage temperature. 100% 1051 No dwell is required at 25°C. Test condition A1, 5 cycles -55°C to +125°C (extremes) >10 minutes. 100% Humidity Life 85°C, 85% RH, 168 Hrs. 100% Interim Electrical VN(DC) VC (Note 3) As specified, but including delta parameter as a minimum. Thermal Shock (Temperature Cycling) Power Burn-In 1038 Final Electrical +VN(DC) VC (Note 3) External Visual Examination 100% Screen Condition B, 85°C, rated VM(AC), 72 hours min. 100% As specified - All parameter measurements must be completed within 96 hours after removal from burn-in conditions. 2071 100% Screen To be performed after complete marking. 100% 3) Custom Types In addition to our comprehensive high-reliability series, Littelfuse can screen and condition to specific requirements. Additional mechanical and environmental capabilities are defined in Table 5. Table 5. Mechanical And Environmental Capabilities (Typical Conditions) Test Name Test Method Description Terminal Strength MIL-STD-750-2036 3 Bends, 90° Arc, 16oz. Weight Drop Shock MIL-STD-750-2016 1500g’s, 0.5ms, 5 Pulses, X1, V1, Z1 Variable Frequency Vibration MIL-STD-750-2056 20g’s, 100-2000Hz, X1, V1, Z1 Constant Acceleration MIL-STD-750-2006 V2, 20,000g’s Min Salt Atmosphere MIL-STD-750-1041 35°C, 24Hr, 10-50g/m2 Day Soldering Heat/Solderability MIL-STD-750-2031/2026 260°C, 10s, 3 Cycles, Test Marking Resistance to Solvents MIL–STD–202-215 Permanence, 3 Solvents Flammability MIL–STD–202-111 15s Torching, 10s to Flameout Cyclical Moisture Resistance MIL–STD–202-106 10 Days Steady-State Moisture Resistance MIL–STD–750-1021.3 85/85 96Hr Biased Moisture Resistance MIL–STD–750-1021.3 Not Recommended for High-Voltage Types Temperature Cycle MIL–STD–202-107 -55°C to 125°C, 5 Cycles High-Temperature Life (Nonoperating) MIL-STD-750-1032 125°C, 24Hr Burn-In MIL-STD-750-1038 Rated Temperature and VRMS Hermetic Seal MIL-STD-750-1071 Condition D Disclaimer Notice - Information furnished is believed to be accurate and reliable. However, users should independently evaluate the suitability of and test each product selected for their own applications. Littelfuse products are not designed for, and may not be used in, all applications. Read complete Disclaimer Notice at www.littelfuse.com/disclaimer-electronics. © 2018 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 08/22/18 Metal-Oxide Varistors (MOVs) High Reliability Varistors Radiation Hardness For space applications, an extremely important property of a protection device is its response to imposed radiation effects. Electron Irradiation A Littelfuse MOV and a Silicon transient suppression diode were exposed to electron irradiation. The V-I curves, before and after test, are shown below. LITTELFUSE MOV 200 100 80 60 PRE TEST 10 8 RADS, 18MeV ELECTRONS 40 It 20 The characteristic voltage current relationship of a P– N Junction is shown below. I 10 8 10 6 10 4 10 2 is CURRENT (A) FIGURE 1. RADIATION SENSITIVITY OF LITTELFUSE V130LA1 AND SILICON TRANSIENT SUPPRESSION DIODE apparent that the Littelfuse MOV was virtually unaffected, even at the extremely high dose of 108 rads, while the Silicon transient suppression diode showed a dramatic increase in leakage current. Neutron Effects A second MOV-Zener comparison was made in response to neutron fluence. The selected devices were equal in area. Figure 2 shows the clamping voltage response of the MOV and the Zener to neutron irradiation to as high as 1015 N/ cm2. It is apparent that in contrast to the large change in the Zener, the MOV is unaltered. At highercurrents where the MOV’s clamping voltage is again unchanged, the Zener device clamping voltage increases by as much as 36%. 300 1.5K 200 INITIAL 200 VARISTOR V130A2 INITIAL AT 10 15 VOLTS 100 80 60 50 40 1.5K 200 AT 10 12 1.5K 200 AT 10 13 20 1.5K 200 AT 10 14 SATURATION CURRENT FORWARD BIAS BREAKDOWN VOLTAGE V REDUCTION IN FAILURE STRESSHOLD BY RADIAL SECONDARY BREAKDOWN REVERSE BIAS FIGURE 3. V-I CHARACTERISTIC OF PN-JUNCTION At low reverse voltage, the device will conduct very little current (the saturation current). At higher reverse voltage VBO (breakdown voltage),the current increases rapidly as the electrons are either pulled by the electric field (Zener effect) or knocked out by other electrons (avalanching). A further increase in voltage causes the device to exhibit a negative resistance characteristic leading to secondary breakdown. This manifests itself through the formation of hotspots, and irreversible damage occurs. This failure threshold decreases under neutron irradiation for Zeners, but not for ZNO Varistors. 30 10 10 The solid and open circles for a given fluence represent the high and low breakdown currents for the sample of devices tested. Note that there is a marked decrease in current (or energy) handling capability with increased neutron fluence. Failure threshold of Silicon semiconductor junctions is further reduced when high or rapidly increasing currents are applied. Junctions develop hot spots, which enlarge until a short occurs if current is not limited or quickly removed. SILICON TRANSIENT SUPPRESSION DIODE V Counterclockwise rotation of the V-I characteristics is observed in Silicon devices at high neutron irradiation levels; in other words, increasing leakage at low current levels and increasing clamping voltage at higher current levels. 1.5K 200 AT 10 15 Gamma Radiation 10 10 8 10 6 10 7 AMPERES 10 5 10 4 10 3 FIGURE 2. V-I CHARACTERISTIC RESPONSE TO NEUTRON IRRADIATION FOR MOV AND ZENER DIODE DEVICES © 2018 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 08/22/18 Radiation damage studies were performed on type V130LA2 varistors. Emission spectra and V-I characteristics were collected before and after irradiation with 106 rads Co60 gamma radiation. Both show no change, within experimental error, after irradiation.