V I S H AY I N T E R T E C H N O L O G Y, I N C . WSC/WSN Conversion Guide Vishay Dale WSC/WSN Wirewound Surface-Mount Resistors Time to Make the Switch! RESOURCES • For technical questions contact [email protected] CONVERSION GUIDE 1/8 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 VMN-PL0010-1510 www.vishay.com V I S H AY I N T E R T E C H N O L O G Y, I N C . WSC/WSN Conversion Guide Vishay Dale Introduction Vishay offers many technologies that cover broad resistance ranges and wattages. There have been many advancements since the release of the original wirewound WSC and the following tables show the overlapping products that are available (grouped by wattage rating). Global Model RTC Power Resistance Range (ppm/ Rating °C) WSL1206…18 L = 0.126 in [3.20 mm] W = 0.063 in [1.60 mm] • Disc drive motor controls H = 0.025 in [0.64 mm] • DC/DC converters L = 0.200 in [5.08 mm] • Li-Ion battery management W = 0.100 in [2.54 mm] • VRMs in notebook PCs H = 0.025 in [0.64 mm] ± 75 ± 0.5 %, ± 1.0 % 0.5 W 0.007 Ω to 0.5 Ω* ± 75 ± 0.5 %, ± 1.0 % 0.5 W 0.1 Ω to 0.99 Ω 1.0 Ω to 4.99 Ω ± 90 ± 50 ± 0.5 %, ± 1.0 %, ± 5.0 % L = 0.200 in [5.08 mm] • Instrumentation W = 0.125 in [3.18 mm] • DC/DC converters H = 0.096 in [2.44 mm] 0.5 W 5.0 Ω to 1.43 kΩ ± 100 ± 50 ± 25 ± 0.5 %, ± 1.0 %, ± 5.0 % L = 0.200 in [5.08 mm] • Automotive controls (body W = 0.125 in [3.18 mm] electronics and powertrain) H = 0.096 in [2.44 mm] • Networking/line cards 1.0 W 0.01 Ω to 0.50 Ω* ± 75 ± 0.5 %, ± 1.0 % 1.0 W 0.01 Ω to 0.50 Ω* ± 75 ± 0.5 %, ± 1.0 % 1.0 W 0.1 Ω to 0.99 Ω 1.0 Ω to 26.50 Ω 26.51 Ω to 2.77 kΩ ± 90 ± 50 ± 20 ± 0.5 %, ± 1.0 %, ± 5.0 % 1.0 W 0.1 Ω to 0.99 Ω 1.0 Ω to 26.50 Ω 26.51 Ω to 2.5 kΩ ± 90 ± 50 ± 20 1.0 W 10 Ω to 10 kΩ ± 100 ± 50 ± 25 2.0 W 0.01 Ω to 1.0 Ω* ± 75 ± 0.5 %, ± 1.0 % 2.0 W 0.1 Ω to 0.99 Ω 1.0 Ω to 9.99 Ω 10 Ω to 4.92 kΩ ± 90 ± 50 ± 20 ± 0.5 %, ± 1.0 %, ± 5.0 % WSLT2010…18 WSLT2512 WSC2515 WSN2515** Applications 0.007 Ω to 0.2 Ω* WSF2012 WSC0001 WSN0001** Dimensions 0.5 W WSL2010 WSC01/2 WSN01/2** Tolerance WSF2515 ± 0.1 %, ± 0.5 %, ± 1.0 %, ± 5.0 % ± 0.5 %, ± 1.0 %, ± 5.0 % WSR2 WSC0002 WSN0002** L = 0.200 in [5.08 mm] • Li-Ion battery management W = 0.100 in [2.54 mm] • D C/DC converters H = 0.025 in [0.64 mm] • VRMs in notebook PCs • Disc drive motor controls L = 0.250 in [6.35 mm] • Automotive controls (body W = 0.125 in [3.18 mm] electronics and powertrain) H = 0.025 in [0.64 mm] L = 0.250 in [6.35 mm] W = 0.150 in [3.81 mm] • Automotive controls H = 0.110 in [2.79 mm] (engine control modules) L = 0.250 in [6.35 mm] • Instrumentation W = 0.150 in [3.81 mm] • Voltage divider circuits H = 0.110 in [2.79 mm] L = 0.250 in [6.35 mm] • Automotive controls (body W = 0.150 in [3.81 mm] electronics and powertrain) H = 0.110 in [2.79 mm] • Networking/line cards • DC/DC converter in switching power supplies L = 0.455 in [11.56 mm] • VRMs in notebook PCs W = 0.275 in [6.98 mm] • Instrumentation H = 0.095 in [2.41 mm] • Automotive controls (body electronics and powertrain) • Automotive controls (engine control modules) L = 0.445 in [11.30 mm] W = 0.275 in [6.98 mm] • Instrumentation H = 0.167 in [4.24 mm] • Voltage divider circuits • Networking/line cards * For full resistance value ranges, reference appropriate data sheet. ** WSN max resistance values are half of the WSC equivalent. CONVERSION GUIDE 2/8 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 VMN-PL0010-1510 www.vishay.com V I S H AY I N T E R T E C H N O L O G Y, I N C . WSC/WSN Conversion Guide Vishay Dale Global Model Power Rating Resistance Range 2.0 W 0.1 Ω to 0.30 Ω 0.31 Ω to 0.99 Ω 1.0 Ω to 9.99 Ω 10 Ω to 4.92 kΩ ± 150 ± 90 ± 50 ± 20 ± 0.5 %, ± 1.0 %, ± 5.0 % 2.0 W 10 Ω to 100 kΩ ± 100 ± 50 ± 25 ± 0.5 %, ± 1.0 %, ± 5.0 % WSC4527 WSN4527** RTC Tolerance (ppm/ °C) WSF4527 WSR3 Dimensions Applications L = 0.455 in [11.56 mm] W = 0.275 in [6.98 mm] • Automotive controls H = 0.167 in [4.24 mm] (engine control modules) • Instrumentation • Voltage divider circuits L = 0.455 in [11.56 mm] • Networking/line cards W = 0.275 in [6.98 mm] H = 0.167 in [4.24 mm] 3.0 W 0.01 Ω to 0.2 Ω* ± 75 ± 0.5 %, ± 1.0 % • DC/DC converter in switching power supplies L = 0.455 in [11.56 mm] • VRMs in notebook PCs W = 0.275 in [6.98 mm] • Automotive controls H = 0.095 in [2.41 mm] (body electronics and powertrain) 3.0 W 0.1 Ω to 0.30 Ω 0.31 Ω to 0.99 Ω 1.0 Ω to 9.99 Ω 10 Ω to 8 kΩ ± 150 ± 90 ± 50 ± 20 ± 0.5 %, ± 1.0 %, ± 5.0 % • Automotive controls (engine control modules) L = 0.690 in [17.53 mm] W = 0.275 in [6.98 mm] • Instrumentation H = 0.280 in [7.11 mm] • Voltage divider circuits • Satellite receivers WSC6927 WSN6927** * For full resistance value ranges, reference appropriate data sheet. ** WSN max resistance values are half of the WSC equivalent. Performance Characteristics Test Thermal Shock Short-Time Overload Low-Temp. Storage High-Temp. Exposure Bias Humidity Mechanical Shock Vibration Load Life Resistance to Solder Heat Moisture Resistance CONVERSION GUIDE Conditions of Test -55 °C to +150 °C, 1000 cycles 5 x rated power for 5 s (4 x for WSR3) -65 °C for 24 h WSL/WSLT ± (0.5 % +0.0005 Ω) ∆R ± (0.5 % +0.0005 Ω) ∆R ± (0.5 % +0.0005 Ω) ∆R Test Limits WSR2 WSR3 WSC/WSN WSF ± (0.5 % ± (0.5 % ± (0.5 % ± (1.0 % +0.0005 Ω) ∆R +0.0005 Ω) ∆R +0.05 Ω) ∆R +0.05 Ω) ∆R ± (0.5 % ± (2.0 % ± (0.2 % ± (0.5 % +0.0005 Ω) ∆R +0.0005 Ω) ∆R +0.05 Ω) ∆R +0.05 Ω) ∆R ± (0.5 % ± (0.5 % ± (0.2 % ± (0.5 % +0.0005 Ω) ∆R +0.0005 Ω) ∆R +0.05 Ω) ∆R +0.05 Ω) ∆R 1000 h at +275 °C (+175 °C for WSC01/2 and WSF, and +170 °C for WSL) ± (1.0 % +0.0005 Ω) ∆R (2.0 % for WLT2010…18) ± (1.0 % ± (1.0 % ± (0.5 % ± (1.0 % +0.0005 Ω) ∆R +0.0005 Ω) ∆R +0.05 Ω) ∆R +0.05 Ω) ∆R +85 °C, 85 % RH, 10 % bias, 1000 h 100 g for 11 m, 5 pulses 10 Hz to 500 Hz in one min, 3 directions, 9 h 1000 h at rated power, +70 °C, 1.5 h “ON,” 0.5 h “OFF” + 260 °C solder, 10 s - 12 s dwell, 25 mm/s emergence ± (0.5 % +0.0005 Ω) ∆R ± (0.5 % +0.0005 Ω) ∆R ± (0.5 % +0.0005 Ω) ∆R ± (0.5 % ± (0.5 % ± (0.2 % ± (0.5 % +0.0005 Ω) ∆R +0.0005 Ω) ∆R +0.05 Ω) ∆R +0.05 Ω) ∆R ± (0.5 % ± (0.5 % ± (0.1 % ± (0.5 % +0.0005 Ω) ∆R +0.0005 Ω) ∆R +0.05 Ω) ∆R +0.05 Ω) ∆R ± (0.5 % ± (0.5 % ± (0.1 % ± (0.5 % +0.0005 Ω) ∆R +0.0005 Ω) ∆R +0.05 Ω) ∆R +0.05 Ω) ∆R ± (1.0 % +0.0005 Ω) ∆R ± (1.0 % ± (2.0 % ± (1.0 % ± (1.0 % +0.0005 Ω) ∆R +0.0005 Ω) ∆R +0.05 Ω) ∆R +0.05 Ω) ∆R ± (0.5 % +0.0005 Ω) ∆R ± (0.5 % ± (0.5 % ± (0.5 % ± (0.5 % +0.0005 Ω) ∆R +0.0005 Ω) ∆R +0.05 Ω) ∆R +0.05 Ω) ∆R MIL-STD-202, method 106, 0 % power ± (0.5 % ± (0.5 % ± (0.5 % ± (0.5 % ± (0.5 % +0.0005 Ω) ∆R +0.0005 Ω) ∆R +0.0005 Ω) ∆R +0.05 Ω) ∆R +0.05 Ω) ∆R (1.0 % for WSLT) 3/8 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 VMN-PL0010-1510 www.vishay.com V I S H AY I N T E R T E C H N O L O G Y, I N C . WSC/WSN Conversion Guide Vishay Dale Surface-Mount Resistors: 0.5 W WSF2012 WSN01/2 Model • The WSC01/2 and WSN01/2 are the original 0.5 W wirewound SMD resistors • It is recommended to convert to the latest technologies, as highlighted on this page WSL = low value, Power Metal Strip® WSC = mid value, wirewound WSN = mid value, wirewound, non-inductive WSF = high value, metal film WSC01/2 WSN01/2 WSC01/2 WSL2010 WSL1206…18 Resistance Values: .007 Ω Recommended model .1 Ω .2 Ω .5 Ω Alternate choice WSL1206…18 WSL2010 2.5 Ω 4.99 Ω 1.43 kΩ Available, but not preferred WSF2012 4 1 3 4 6 2 1 3 6 4 3 1)Ceramic core 1)Resistive element 1 2 5 1)Ceramic core 2)Resistor end cap 2)Plated terminal 2)Resistor end cap 3)Resistance wire 3)Terminal/element weld 3)Resistance element 4)Subassembly coating 4)Silicone coating with ink print 4)Subassembly coating 5 2 5)Plated terminal 5)Plated terminal 6)Epoxy mold with ink print 6)Epoxy mold with ink print Solder Pad Layout I b a Model Solder Pad Dimensions in Inches [Millimeters] Technology Selection Criteria a b l Smallest Footprint Lowest Inductance Pulse Handling RTC Lead Time Cost WSC01/2 0.085 [2.16] 0.070 [1.78] 0.080 [2.03] Good Good Best Better Better Good WSN01/2 0.085 [2.16] 0.070 [1.78] 0.080 [2.03] Good Better Better Better Good Good WSL1206…18 0.062 [1.57] 0.070 [1.78] 0.030 [0.76] Best Best Better Best Best Better WSL2010 0.055 [1.40] 0.120 [3.05] 0.130 [3.30] Better Best Best Best Best Best WSF2012 0.085 [2.16] 0.070 [1.78] 0.080 [2.03] Good Better Good Good Better Better CONVERSION GUIDE 4/8 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 VMN-PL0010-1510 www.vishay.com V I S H AY I N T E R T E C H N O L O G Y, I N C . WSC/WSN Conversion Guide Vishay Dale Surface-Mount Resistors: 1W WSF2515 WSN2515 WSC2515 • T he WSC0001 and WSN0001 are the original 1 W wirewound SMD resistors Model WSC0001 • It is recommended to convert to the latest technologies, as highlighted on this page WSLT2512 WSL = low value, Power Metal Strip® WSC = mid value, wirewound WSN = mid value, wirewound, non-inductive WSF = high value, metal film WSC0001 WSN0001 3 7 1 WSN0001 WSLT2010…18 Resistance Values: .01 Ω Recommended model WSLT2010…18 WSLT2512 .1 Ω 1 10 Ω Alternate choice 1 3 4 1 kΩ 2.77 kΩ 10 kΩ 2.5 kΩ Available, but not preferred WSC2515 WSN2515 4 2 .5 Ω WSF2515 7 5 2 1 3 4 7 1)Ceramic core 1)Resistive element 2 5 6 1)Ceramic core 2)Resistor end cap 2)Plated terminal 2)Resistor end cap 2)Resistor end cap 3)Resistance wire 3)Terminal/element weld 3)Resistance wire 3)Resistance element 4)Subassembly coating 4)Silicone coating with ink print 4)Subassembly coating 4)Subassembly coating 5)Connection - cap to terminal 5)Connection - cap to terminal 6)Plated leadframe terminal 6)Plated terminal 6)Plated terminal 7)LCP mold with laser print 7)LCP mold with laser print 7)LCP mold with laser print 6 5 4 2 5)Connection - cap to leadframe terminal Model WSC0001 WSN0001 WSC2515 WSN2515 WSLT2010…18 WSLT2512 WSF2515 CONVERSION GUIDE Solder Pad Dimensions in Inches [Millimeters] a b l 0.090 [2.29] 0.090 [2.29] 0.090 [2.29] 0.090 [2.29] 0.055 [1.40] 0.065 [1.65] 0.090 [2.29] 0.115 [2.92] 0.115 [2.92] 0.115 [2.92] 0.115 [2.92] 0.120 [3.05] 0.145 [3.68] 0.115 [2.92] 0.115 [2.92] 0.115 [2.92] 0.120 [3.05] 0.120 [3.05] 0.130 [3.30] 0.160 [4.06] 0.120 [3.05] 3 6 1)Ceramic core Technology Selection Criteria Smallest Footprint Lowest Inductance Pulse Handling RTC Lead Time Cost Good Good Best Better Good Good Good Better Better Better Good Good Good Good Best Better Better Better Good Better Better Better Good Good Best Best Better Best Best Best Better Best Best Best Best Best Good Better Good Good Better Better 5/8 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 VMN-PL0010-1510 www.vishay.com V I S H AY I N T E R T E C H N O L O G Y, I N C . WSC/WSN Conversion Guide Vishay Dale Surface-Mount Resistors: 2W WSF4527 WSN4527 • The WSC0002 and WSN0002 are the original 2 W wirewound SMD resistors WSC4527 Model WSN0002 WSC0002 • It is recommended to convert to the latest technologies, as highlighted on this page WSR2 WSR = low value, Power Metal Strip WSC = mid value,wirewound WSN = mid value, wirewound, non-inductive WSF = high value, metal film ® WSC0002 WSN0002 6 4 5 3 7 Resistance Values: Recommended model WSR2 1 .01 Ω 2 .1 Ω 3 10 Ω 2.46 kΩ 4.92 kΩ 100 kΩ Alternate choice Available, but not preferred WSC4527 WSN4527 4 2 1 Ω 1 6 5 2 1 3 WSF4527 7 4 5 6 2 1 3 4 7 1)Ceramic core 1)Resistive element 1)Ceramic core 1)Ceramic core 2)Resistor end cap 2)Plated terminal 2)Resistor end cap 2)Resistor end cap 3)Resistance wire 3)Terminal/element weld 3)Resistance wire 3)Resistance element 4)Subassembly coating 4)LCP mold with laser print 4)Subassembly coating 4)Subassembly coating 6)Plated leadframe terminal 5)Connection - cap to axial lead, axial lead to leadframe terminal 5)Connection - cap to axial lead, axial lead to leadframe terminal 7)LCP mold with laser print 6)Plated terminal 6)Plated terminal 7)LCP mold with laser print 7)LCP mold with laser print 5)Connection - cap to leadframe terminal Model Solder Pad Dimensions in Inches [Millimeters] Technology Selection Criteria a b l Smallest Footprint Lowest Inductance Pulse Handling RTC Lead Time Cost WSC0002 0.155 [3.94] 0.230 [5.84] 0.205 [5.21] Good Good Best Better Good Good WSN0002 0.155 [3.94] 0.230 [5.84] 0.205 [5.21] Good Better Better Better Good Good WSC4527 0.155 [3.94] 0.230 [5.84] 0.205 [5.21] Good Good Better Better Better Better WSN4527 0.155 [3.94] 0.230 [5.84] 0.205 [5.21] Good Better Better Better Good Good WSR2 0.155 [3.94] 0.230 [5.84] 0.205 [5.21] Best Best Best Best Best Best WSF4527 0.155 [3.94] 0.230 [5.94] 0.205 [5.21] Good Better Good Good Better Better CONVERSION GUIDE 6/8 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 VMN-PL0010-1510 www.vishay.com V I S H AY I N T E R T E C H N O L O G Y, I N C . WSC/WSN Conversion Guide Vishay Dale Surface-Mount Resistors: 3W WSN6927 Model • The WSC6927 and WSN6927 are the original 3 W wirewound SMD resistors WSC6927 WSR3 Resistance Values: • It is recommended to convert to the WSR3 for values of 0.2 Ω and below .01 Ω Recommended model .1 Ω .2 Ω Alternate choice 4 kΩ 8 kΩ Available, but not preferred WSR = low value, Power Metal Strip® WSC = mid value, wirewound WSN = mid value, wirewound, non-inductive WSR3 WSC6927 WSN6927 2 5 1)Ceramic core 3 1 7 4 4 2 6 3 1 1)Resistive element 2)Resistor end cap 2)Plated terminal 3)Resistance wire 3)Terminal/element weld 4)Subassembly coating 4)LCP mold with laser print 5)Connections - cap to axial lead, axial lead to leadframe terminal 6)Plated leadframe terminal 7)LCP mold with ink print Solder Pad Layout I b a Model Solder Pad Dimensions in Inches [Millimeters] Technology Selection Criteria a b l Smallest Footprint Lowest Inductance Pulse Handling RTC Lead Time Cost WSC6927 0.155 [3.94] 0.235 [5.97] 0.470 [11.94] Good Good Good Good Better Better WSN6927 0.155 [3.94] 0.235 [5.97] 0.470 [11.94] Good Better Good Good Good Good WSR3 0.155 [3.94] 0.230 [5.84] 0.205 [5.21] Best Best Best Best Best Best CONVERSION GUIDE 7/8 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 VMN-PL0010-1510 www.vishay.com V I S H AY I N T E R T E C H N O L O G Y, I N C . WSC/WSN Conversion Guide Vishay Dale SEMICONDUCTORS PASSIVE COMPONENTS MOSFETs Segment Resistors and Inductors Segment MOSFETs Low-Voltage TrenchFET® Power MOSFETs Medium-Voltage Power MOSFETs High-Voltage Planar MOSFETs High-Voltage Superjunction MOSFETs Automotive-Grade MOSFETs ICs Power Management and Power Control ICs Smart Load Switches Analog Switches and Multiplexers Film Resistors Metal Film Resistors Thin Film Resistors Thick Film Resistors Power Thick Film Resistors Metal Oxide Film Resistors Carbon Film Resistors Wirewound Resistors Vitreous, Cemented, and Housed Resistors Braking and Neutral Grounding Resistors Custom Load Banks Power Metal Strip® Resistors Battery Management Shunts Crowbar and Steel Blade Resistors Thermo Fuses Chip Fuses Pyrotechnic Initiators/Igniters Variable Resistors Cermet Variable Resistors Wirewound Variable Resistors Conductive Plastic Variable Resistors Contactless Potentiometers Hall Effect Position Sensors Precision Magnetic Encoders Networks/Arrays Non-Linear Resistors NTC Thermistors PTC Thermistors Varistors Magnetics Inductors Wireless Charging Coils Transformers Connectors Diodes Segment Rectifiers Schottky Rectifiers Ultrafast Recovery Rectifiers Standard and Fast Recovery Rectifiers High-Power Rectifiers/Diodes Bridge Rectifiers Small-Signal Diodes Schottky and Switching Diodes Zener Diodes Tuner/Capacitance Diodes Bandswitching Diodes RF PIN Diodes Protection Diodes TVS Diodes or TRANSZORB® (unidirectional, bidirectional) ESD Protection Diodes (including arrays) Thyristors/SCRs Phase-Control Thyristors Fast Thyristors IGBTs Power Modules Input Modules (diodes and thyristors) Output and Switching Modules (contain MOSFETs, IGBTs, and diodes) Custom Modules Optoelectronic Components Segment Infrared Emitters and Detectors Optical Sensors Infrared Remote Control Receivers Optocouplers Phototransistor, Photodarlington Linear Phototriac High-Speed IGBT and MOSFET Driver Solid-State Relays LEDs and 7-Segment Displays Infrared Data Transceiver Modules Custom Products CONVERSION GUIDE Capacitors Segment Tantalum Capacitors Molded Chip Tantalum Capacitors Molded Chip Polymer Tantalum Capacitors Coated Chip Tantalum Capacitors Solid Through-Hole Tantalum Capacitors Wet Tantalum Capacitors Ceramic Capacitors Multilayer Chip Capacitors Multilayer Chip RF Capacitors Disc Capacitors Film Capacitors Power Capacitors Heavy-Current Capacitors Aluminum Capacitors ENYCAP™ Energy Storage Capacitors 8/8 THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000 VMN-PL0010-1510 www.vishay.com