Pulse Withstanding Chip Resistors Welwyn Components PWC Series • Excellent pulse withstand performance • Improved working voltage • Improved power rating • Standard chip sizes (0805 to 2512) • Custom designs available Electrical Data Size Power @70°C W Resistance range 0805 1206 0.125 0.33 Ohms Tolerance V TCR ppm/°C Operating temperature Pad / trace area* 0.75 1.5 10R to 1M: 0.5, All values: 1, 5 150 200 400 500 <10R:200 ≥10R:100 °C Thermal Impedance 2512 1R0 to 10M % LEV 2010 -55 to +155 °C/W 220 160 80 50 mm2 40 50 60 100 Values E24 or E96 preferred other values to special order Pulse capability See graphs - full application note available on request *Recommended minimum pad & adjacent trace area for each termination for rated power dissipation on FR4 PCB Physical Data Dimensions of PWC resistors are given below in mm and weight in g 0805 L W T max A B C Wt. 2.0±0.3 1.25±0.2 0.6 0.3±0.15 0.9 min 0.3±0.1 0.009 1206 3.2±0.4 1.6±0.2 0.7 0.4±0.2 1.7 min 0.4±0.15 0.020 2010 5.1±0.3 2.5±0.2 0.8 0.6±0.3 3.0 min 0.6±0.25 0.036 2512 6.5±0.3 3.2±0.2 0.8 0.6±0.3 4.4 min 0.6±0.25 0.055 T A B L A W Wrap-around terminations (3 faces) Construction Marking Thick film resistor material, overglaze and organic protection are screen printed on a 96% alumina substrate. Wrap-around terminations have an electroplated nickel barrier and solder coating, this ensures excellent ‘leach’ resistance properties and solderability. Components are not marked. Reels are marked with type, value, tolerance, date code and quantity. Solvent Resitance The body protection is resistant to all normal industrial cleaning solvents suitable for printed circuits. General Note Welwyn Components reserves the right to make changes in product specification without notice or liability. All information is subject to Welwyn’s own data and is considered accurate at time of going to print. © Welwyn Components Limited · Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: [email protected] · Website: www.welwyn-tt.com A subsidiary of TT electronics plc Issue G · 03.06 37 Pulse Withstanding Chip Resistors Welwyn Components PWC Series Performance Data Size Load at rated power: Shelf life test: 1000 hours at 70°C 12 months at room temperature Maximum Typical ∆R% 1 0.25 ∆R% 0.1 0.02 Derating from rated power at 70°C Zero at 155°C Overload: 6.25 x rated power for 2 seconds ∆R% 1 0.1 Dry heat: 1000 hours at 155°C ∆R% 1 0.2 Long term damp heat ∆R% 1 0.25 Temperature rapid change ∆R% 0.25 0.05 Resistance to solder heat ∆R% 0.25 0.05 Voltage proof Volts 500 Note: A 0.01 Ohm addition to be added to the performance of all resistors <10 Ohms. Pulse Performance Data 1.2/50µs Lightning Surge Peak voltage (volts) 10000 1000 0805 1206 2010 2512 100 10 Lightning Surge 1 10 100 Resistors are tested in accordance with IEC 60 115-1 using both 1.2/50µs and 10/700µs pulse shapes. The limit of acceptance is a shift in resistance of less than 1% from the initial value. 1000 10000 Value (ohms) 100000 1000000 10000000 10/700µs Lightning Surge Peak Voltage (Volts) 10000 1000 0805 1206 2010 2512 100 10 1 10 100 1000 10000 Value (ohms) © Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: [email protected] · Website: www.welwyn-tt.com 100000 1000000 10000000 Issue G · 03.06 Pulse Withstanding Chip Resistors Welwyn Components PWC Series Pulse Performance Data Single Pulse Pulse Power P (W) 1000 100 0805 1206 2010 2512 10 1 0.0001 0.001 Single Impulse Continuous Load Due to Repetitive Pulses The continuous load grpah was obtained by applying repetitive rectangular pulses where the pulse period was adjusted so that the average power dissipated in the resistor was equal to its rated power at 70°C. Again the limit of acceptance was a shift in resistance of less than 1% from the initial value. 0.1 1 Continuous Pulses 100 Pulse Power P (W) The single impulse graph is the result of 50 impulses of rectangular shape applied at one minute intervals. The limit of acceptance was a shift in resistance of less than 1% from the initial value. The power applied was subject to the restrictions of the maximum permissible impulse voltage graph as shown. 0.01 Pulse Duration ti (s) 10 0805 1206 2010 2512 1 0.1 0.0001 0.001 0.01 Pulse Duration ti (s) 0.1 1 Pulse Voltage Pulse Voltage (Volts) 10000 1000 0805 1206 2010 2512 100 10 0.0001 0.001 0.01 Pulse Duration ti (s) © Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: [email protected] · Website: www.welwyn-tt.com 0.1 1 Issue G · 03.06 Pulse Withstanding Chip Resistors Welwyn Components PWC Series Temperature Derating Curve Temperature Rise /°C % of Rated Power Thermal Performance Data 125 100 75 50 25 0 -15 70 Ambient Temperature /°C 155 Temperature Rise Curves 80 0805 1206 2010 2512 60 40 20 0 0 0.5 1 Power Dissipation /W 1.5 Packaging 0805 and 1206 PWC series resistors are supplied on 8mm carrier tape and 7 inch reels as per IEC 286-3, quantity per reel; 3000. T2 8mm tape: 9mm ± 0.5 12mm tape: 13mm ± 0.5 P0 D0 T P2 9.0 +- 0.1 0.15 33 ± 1.0 B0 G 80 ± 2 178 ± 2 13 ± 0.5 W F 2010 and 2512 PWC series resistors are supplied on 12mm carrier tape and 7 inch reels as per IEC 286-3, quantity per reel; 2010 : 3000pcs; 2512 : 1800pcs. E Marking T1 0.8 ± 0.15 2.5 ± 0.5 A0 K0 D1 P1 Reels of 1000pcs are available on request. Tape dimensions in mm 0805 1206 2010 2512 W ±0.3 8 8 12 12 P1 ±0.1 4 4 4 8 P0 ±0.1 4 4 4 4 P2 ±0.05 2 2 2 2 D0 ±0.1 1.5 1.5 1.5 1.5 D1 ±0.2 1 1 1.5 1.5 E ±0.1 1.75 1.75 1.75 1.75 F ±0.05 3.5 3.5 5.5 5.5 A0 ±0.1 1.65 1.95 2.79 3.61 B0 ±0.1 2.45 3.55 5.89 6.96 K0 ±0.1 0.8 1.0 0.91 1.17 T ±0.05 0.2 0.2 0.28 0.28 T1 nom 0.05 0.05 0.06 0.06 T2 ±0.15 1.1 1.3 1.21 1.45 Application Notes PWC resistors are ideally suited for handling by automatic methods due to their rectangular shape and the small dimensional tolerances. Electrical connection to a ceramic substrate or to a printed circuit board can be made by reflow or wave soldering of wrap-around terminations. Wrap-around terminations provide good leach properties and ensure reliable contact. Due to the robust construction, the PWC can be immersed in the solder bath for 30 seconds at 260°C. This enables the resistor to be mounted on one side of a printed circuit board and wire-leaded components applied on the other side. PWC resistors themselves can operate at a maximum temperature of 155°C. For soldered resistors, the joint temperature should not exceed 110°C. This condition is met when the stated power levels at 70°C and recommended pad and trace areas are used. Allowance should be made if smaller areas of copper are used. A full Application Note on the PWC Series is available. Ordering Procedure Specify type reference etc as shown in this example of PWC2512 10K ohms 1%. Type PWC 2512 - 10K F Size Value (use IEC62 code) Tolerance (use IEC62 code) D F J 0.5% 1% 5% © Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: [email protected] · Website: www.welwyn-tt.com Issue G · 03.06