Low Resistance Metal Alloy Resistor LRMA Series Resistance Metal Alloy Resistor ·Low Resistance range 1 to 100mΩ ·LRMA High temperature operation to 170°C Series · Low thermal EMF version ·• High power version Resistance range 1 to 100mΩ ·• Current sensing foroperation power electronics High temperature to 170°C Low thermal EMF version free ·• RoHS compliant & halogen • • • High power version Current sensing for power electronics RoHS compliant & halogen free Electrical Data LRMA Version Size Power rating @70°C Overload rating (5s) Resistance range W W mΩ Standard values 1 mΩ Resistance tolerance TCR (25 to 125°C) Ambient temperature Insulation resistance Element alloy Coating % ppm/°C °C MΩ LRMA Version Size T (Standard) 2512 ≤R01: 2, >R01: 1 ≤R01: 10, >R01: 5 1 to 50 1, 1.5, 2, 3, 4, 5, 7, 8, 9, 10, 11, 12, 15, 18, 20, 25, 30, 33, 40, 50 1, 5 >R01: ±75 >R001 & ≤R01: ±100, -55 to 170 >100 Cu-Ni or Mn-Cu Black 1206 M (Low thermal EMF) 2512 Power rating @70°C Overload rating (5s) Resistance range W W mΩ 1 5 5 to 30 ≤R02: 2, >R02: 1 ≤R02: 10, >R02: 5 5 to 40 Standard values 1 mΩ 5, 10, 15, 20, 25, 30 5, 10, 20, 30, 40 Resistance tolerance TCR (25 to 125°C) Ambient temperature Insulation resistance Element alloy Coating % ppm/°C >R01: ±75, MΩ Black 1, 5 ≤R01: ±100 -55 to 170°C >100 Mn-Cu Green P (Power) 2512 3 15 3 to 100 3, 5, 10, 11, 15, 20, 25, 30, 40, 50, 80, 100 R001: ±275 N (Inverse) 0815 1 2 5 1 to 30 1, 6, 8, 10, 15, 20, 25, 30 ±100 2 Cu-Ni Black Notes: 1. Non-standard values may be available for high volume requirements. 2. Requires 300mm copper pad & trace area Physical Data (All dimensions in mm and nominal weight in g) Size L W C t Wt 1206 3.2 ±0.2 1.6 ±0.2 0.5 ±0.3 0.6 ±0.2 18.3 0815 2.1 ±0.25 3.75 ±0.3 0.5 ±0.2 0.7 ±0.2 14.1 0.65 ±0.25 57 to 63 2512 ≤R002 2512 >R002 2.0 ±0.2 6.4 ±0.2 3.2 ±0.2 0.9 ±0.2 General Note General Note TT electronics reserves the right to make changes in product specification without notice or liability. 08/10 Welwyn Components reserves the right to make changes in product specification without notice or liability All subjecttoto TT electronics’ and is considered at time of going to print. All information information isissubject Welwyn’s own dataown anddata is considered accurate ataccurate time of going to print. www.bitechnologies.com www.irctt.com www.welwyn-tt.com Welwyn Components © TT electronics plc Limited Bedlington, Northumberland NE22 7AA, UK Telephone: +44 (0) 1670 822181 • Facsimile: +44 (0) 1670 829465 • Email: [email protected] • Website: www.welwyn-tt.com 09. 11 Low Resistance Low Alloy Resistance Metal Resistor Metal Alloy Resistor LRMA Series LRMA Series Construction Coating (UL94-V0) Copper electrode with nickel then tin plating Low TCR resistance alloy plate Marking The components are marked with ohmic value, e.g. “R002” = 2mΩ, “R010” = 10 mΩ. Solvent Resistance The component is resistant to all normal industrial cleaning solvents suitable for printed circuits. Performance Data Load at rated power (cyclic load, 1000 hours at 70C) Short term overload (5 x rated power for 5s) Humidity (1000 hours, 85°C, 85%RH) Temperature cycle (-40 to +125°C, 1000 cycles, 15 minute dwell) Resistance to solder heat (260°C ±5°C for 20s ±1s) Solderability (245°C ±5°C for 2s ±0.5s) Dry heat (1000 hours at 170C) Low temperature storage (1000 hours at -55°C) Substrate bending (board 1.6mm, fulcrum spacing 90mm, deflection 2mm) Insulation resistance (1 minute @ 100Vdc) ±R ±R ±R ±R ±R Maximum (%) 1 0.5 0.5 0.5 0.5 ±R ±R ±R 0.5 0.5 0.5 Typical (%) >95% coverage >100M 0.3 0.15 0.15 0.15 0.3 0.3 0.15 0.3 Thermal Performance & Mounting Typical Temperature Rise Temperature Rise (°C) Proportion of Pr Temperature Derating 100% 80% 60% 40% 20% 0% -30 20 70 120 Hot spot 100 80 60 40 Joint 20 0 0% 170 Ambient Temperature (°C) Reference Pad Dimensions (mm) Size a b L 1.8 1.9 1.4 1206 7.9 1.5 0.9 0815 4.0 3.1 1.3 2512 ≤R002 4.0 2.1 4.1 2512 >R002 120 20% L b a Current 40% 60% 80% 100% Proportion of Pr Sense The temperature rise shown is highly dependent on mounting conditions. Reference conditions assume 20 copper with thermal vias to multiple layers. The self-heating in the current tracks should be kept negligible, or allowed for by temperature derating. 08/10 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 General Note TT electronics reserves the right to make changes in product specification without notice or liability. All information is subject to TT electronics’ own data and is considered accurate at time of going to print. www.bitechnologies.com www.irctt.com www.welwyn-tt.com © TT electronics plc 09. 11 Low Resistance Metal ResistorMetal Alloy Resistor Low Alloy Resistance LRMA LRMASeries Series Packaging Bottom Tape Wr ΦC ΦB ΦA Tr Paper Tape Size Tape 1206 Paper A 2.0 B 3.6 W 8.0 F 1.75 5.5 1.75 5.5 1.75 ±0.15 ±0.2 ±0.2 ±0.05 ±0.2 ±0.2 ±0.2 ±0.1 ±0.2 ±0.2 ±0.05 0815 Emboss 2.6 3.6 2512 Emboss ±0.2 Storage 4.5 6.9 12 12 E 3.5 P1 4.0 P2 2.0 P0 ΦD0 4.0 1.5 0.84 ΦC Wr 178 ±0.2 60 ±1 13 ±1 9 ±1 1.55 1.1 178 ±0.2 60 ±1 13 ±1 13 ±1 15.4 ±2 ±0.1 ±0.1 ±0.05 ±0.1 +0.1/-0 ±0.1 +-0.1 ±0.2 ±0.1 ±0.05 ±0.1 ±0.1 ±0.05 ±0.05 4.0 4.0 2.0 2.0 4.0 4.0 1.5 +0.1/-0 t ±0.1 ±0.1 0.85 ±0.15 ΦA ΦB Tr 11.5 ±1 178 ±0.2 60 ±1 13 ±1 13 ±1 15.4 ±2 Conditions: 5°C to 35°C and 40% to 75%RH Shelf life: 2 years from manufacture Processing LRMA series resistors are suitable for both wave and IR reflow soldering. The recommended reflow profile for Pbfree SAC305 alloy (Sn 96.5%, Ag 3%, Cu 0.5%) soldering is as follows: Pre-heat: 60s to 120s at 150°C to 180°C Soldering: 20s to 40s at ≥230°C Peak: 5s at 250°C to 255°C Ordering Procedure Example: LRMA low thermal EMF version in 2512 size and at 10 milliohms and 1% tolerance packed in tape. LRMAM2512–R01FT4 Type Version T P M N Size Value (use IEC62 code) Tolerance (use IEC62 code) F J 1% 5% Packing T5 T4 Tape 1206 0815, 2512 5000/reel 4000/reel Standard 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. 08/10 General Note Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK (0) 1670 • Facsimile: +44 (0)in1670 829465 • Email: [email protected] Website: www.welwyn-tt.com TTTelephone: electronics+44 reserves the822181 right to make changes product specification without notice or• liability. All information is subject to TT electronics’ own data and is considered accurate at time of going to print. www.bitechnologies.com www.irctt.com www.welwyn-tt.com © TT electronics plc 09. 11