PR_C.qxd 1/5/03 8:58 am Page 1 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 PR5 Power rating at 70°C watts 0.25 0.5 Resistance range ohms 100R – 240K 100R – 1M volts 250 350 ppm/°C 25 25 0.1, 0.25, 0.5, 1 0.1, 0.25, 0.5, 1 E192 E192 Limiting element voltage TCR* Resistance tolerance % Standard values Thermal impedance °C/watt Ambient temperature range 140 112 °C -55 to 155 *15ppm/°C available by request Physical Data Dimensions (mm) & Weight (g) PCB Min. mounting bend radius Wt.nom Type L Max D Max f min d nom centres PR4 6.2 2.5 21 0.6 10.2 0.6 0.3 PR5 9.0 3.6 19.6 0.8 12.7 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 Solder-coated 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. © 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 182 A subsidiary of TT electronics plc Issue C · 04.03 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 70°C 0.5 Derating from rated power at 70°C zero at 155°C 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 volts 400 min Voltage proof 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 shown in the Lead Form Information section. 6 f2 52 6 Body location f1 – f2 ≤ 1.4 mm Standard Quantities Per Package Type PR4 PR5 Large ammo pack 5000 2500 © 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 C · 04.03 183