Precision Metal Film Resistors Welwyn Components PR series * Low cost precision resistors * Tolerances down to 0.1% * TCR down to 15ppm/C Electrical Data PR4 Power rating at 70C watts Resistance range ohms Limiting element voltage volts PR5 0.5 0.25 100R - 1M 250 350 TCR (20C to 70C) ppm/C 240K: 15, 25, 50 Resistance tolerance % 500K: 0.1, 0.25, 0.5, 1 Standard values >240K: 25, 50 >500K: 0.25, 0.5, 1 E24, E96 Thermal impedance C/watt Ambient temperature range 140 C 112 -55 to 155 Physical Data Dimensions (mm) & Weight (g) Type L Max D Max f min d nom PC mounting centres PR4 6.2 2.5 21 0.6 10.2 PR5 9.0 3.6 19.6 0.8 12.7 Min. bend radius Wt. nom 0.6 0.3 1.2 0.5 Construction Terminations The resistance element is a precisely controlled thin film of metal alloy sputtered on to a high purity ceramic core, protected by a moisture-resistant, high dielectric strength coating applied so that terminations remain completely clear. Material Strength This permits a well defined body length (clean lead to clean lead dimension L). Solderability d D L f Hot tin dipped copper wire The terminations meet the requirements of IEC 68.2.21 The terminations meet the requirements of IEC 115-1, Clause 4.17.3.2 Marking Resistors are colour coded with 5 bands. IEC 62 colours are used. Solvent Resistance The body protection and marking are 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. (c) Welwyn Components Limited * Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 * Facsimile: +44 (0) 1670 829465 * Email: info@welwyn-tt.com * Website: www.welwyn-tt.com 182 A subsidiary of TT electronics plc 07. 08 PR_C.qxd 1/5/03 8:58 am Page 2 Precision Metal Film Resistors Welwyn Components PR series Performance Data Maximum R % Load: 1000 hours at 70C 0.5 Derating from rated power at 70C zero at 155C Short term overload R % Climatic R % 0.25 0.5 Climatic category 55/125/56 Long term damp heat R % 0.5 Temperature rapid change R % 0.25 Resistance to solder heat R % 0.25 Vibration and bump R % 0.1 Insulation resistance ohms > 1G Voltage proof volts PR4: 500 min, PR5: 700 min Packaging All PR resistors are supplied tape packed ready for loading on to automatic sequencing and insertion machines. 5 Component wires will not protrude beyond the outside edge of the tapes. Alternative packaging available by request. f1 Lead formed resistors can also be supplied. Standard options of Lancet, Radial and Goalpost forming are available. 6 f2 52 6 Body location f1 - f2 1.4 mm Ordering Procedure Example: PR4 with TCR of 15ppm/ C at 10 kilohms and 0.1% tolerance in an ammo pack box of 5000 pieces PR4Y- 10KBI Type TCR Y C 15 ppm/ C 25 ppm/ C 50 ppm/ C Value (use IEC62 code) Tolerance (use IEC62 code) B C 0.1% 0.25% D F Packing I Ammo 0.5% 1% PR4 PR5 5000/box 2500/box Standard (c) Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 * Facsimile: +44 (0) 1670 829465 * Email: info@welwyn-tt.com * Website: www.welwyn-tt.com 07. 08 183