LVK Series Four Terminal High Precision Current Sense Current sense resistors enable the measurement of current flow in a circuit by monitoring a voltage drop across a precisely calibrated resistance. The LVK chip features four terminals, also known as a “Kelvin” configuration. This configuration enables current to be applied through two opposite terminals and a sensing voltage to be measured across the other two terminals, eliminating the resistance and temperature coefficient of the terminals for a more accurate current measurement. Isolating the voltage and current terminals (see schematic) facilitates a very accurate current measurement. Ohmite’s proprietary technology offers an excellent Temperature Coefficient of Resistance (TCR) even for very low resistance values. The resistive element consists of a durable, anti-corrosive metal alloy that combines reliable performance with the ability to withstand harsh environments. F e at u r e s • Designed for automatic insertion • Industry standard sizes • High-precision Kelvin connect capability in a small package S e r i e s S p e c i f i c at i o n s Power ResistanceMax. Over Current Pkg. Rating Range TCR Available Max. Max. Series Size (W @70°C) (Ω) (ppm/°C) Tolerance Values Power Current LVK12 1206 0.5W 0.01-0.100 50ppm 0.5%, 1% E12 20W 20A LVK20 2010 0.75W 0.01-0.05 50ppm 0.5%, 1% E12 29W 23A LVK24 2412 1.0W 0.01-0.100 50ppm 0.5%, 1% E12 38W 27A 0.001 300ppm LVK25 1224 2.0W 0.002-0.004 200ppm 1% 1, 2, 3, 5, 9,10mΩ 150W 200A 0.005-0.01 100ppm characteristics Res. Range Operating Temp. Range Rated Ambient Temperature Resistance Tolerance Temperature Coefficient Coating Material Terminals Max. Over Current Storage conditions 12 0.001Ω - 0.010Ω -40°C to +125°C +70°C 0.5% and 1% standard LVK12, LVK20, LVK24: 50ppm standard LVK25: 100ppm, 200ppm, or 300ppm based on resistance value epoxy resin 100% matte tin Time applied: 10ms max. Interval: 60sec min. Max. over current = √(Max. power÷ Resistance value) or max. current, whichever is smaller. Temperature: 5°C ~ 35°C Humidity: 25% ~ 70% 1-866-9-OHMITE • Int’l 1-847-258-0300 • Fax 1-847-574-7522 • www.ohmite.com • [email protected] LVK Series Four Terminal High Precision Current Sense performance characteristics Test Items Overload Endurance at 70°C Moisture resistance Rapid change of temperature Resistance to soldering heat Performance Requirements ±(0.5%+0.0005Ω) ±(0.5%+0.0005Ω) ±(0.5%+0.0005Ω) ±(0.5%+0.0005Ω) Test Methods / standard: JIS C 5201.1 Rated voltage x 1.5 for 5s 70°C±3°C, Rated voltage 1.5h ON, 0.5h OFF, 1000h 60°C±2°C, 90%~95% RH, Rated voltage 1.5h ON, 0.5h OFF, 1000h -40°C (30min.)/+125°C (30min.), 5 cycles ±(0.5%+0.0005Ω) 260°C±5°C for 10s±1s Substrate bending ±(0.5%+0.0005Ω) Bending width: 2mm for 10s±1s, Glass epoxy substrate with thickness of 1.6mm Solderability 95% or more of the electrode surface 245°C±5°C for 3s±0.5s shall be covered with new solder Reflow Temperature Profile For lead free soldering (Sn-Ag-Cu solder) Preheating: 130° ~ 180° 60s ~ 90s Heating: Over 220° 30s ~ 90s Peak: 240° ~ 260° Max. 10s Ramp-up rate: Time above liquidous: Ramp-down rate: Max. number of reflow: Temperature °C 300 max 3°C/sec. 60 – 150 sec. max 6°C/sec. 2 Peak 240 ~ 260℃ Max. 10s 250 200 Heating 150 Over 220℃ 30s ~ 90s Preheating 100 130 ~ 180℃ 60 ~ 90 sec. 50 Time (sec.) dimensions (mm) LVK 12, LVK20, LVK24 (0.5, 0.75 & 1 watt) L 2 4 3 a b W t LVK25 (2 watt) g 1. Electrode 2. Protection coat 1 3. Almina substrate 4. Resistor L Schematic a V b I I V = sensing terminal (voltage) I = current terminal W Layout for illustration only, part can be rotated 180° without effect to the circuit. f d t Land Pattern e Note that LVK25 has a vertical orientation with the current flow along the short edge of the resistor. Size LVK12 (1206) LVK20 (2010) LVK24 (2412) LVK25 (1224) L W t a b d e f g 3.2 ±0.2 1.6 ±0.2 0.5 ±0.15 1.0 ±0.2 0.55 ±0.2 1.10 0.30 1.00 1.75 0.5 ±0.15 2.1 ±0.2 1.2 ±0.2 5.0 ±0.2 6.4 ±0.2 3.2 ±0.2 2.5 ±0.2 3.2 ±0.2 6.4 ±0.2 0.5 ±0.15 0.5 ±0.2 1.7 ±0.2 0.4 ±0.2 V 0.9 ±0.2 2.7 ±0.2 1.55 1.90 1.40 1-866-9-OHMITE • Int’l 1-847-258-0300 • Fax 1-847-574-7522 • www.ohmite.com • [email protected] 0.50 0.60 2.20 13 1.40 2.00 1.00 2.55 3.25 3.30 LVK Series Four Terminal High Precision Current Sense ta p e a n d r e e l (mm) Tape Reel P0 T D0 Direction of feed P2 2mm ±0.5 13mm ±0.3 (LVK12) 15mm ±0.3 (LVK 20, 24, 25) E F D1 T2 A B W F E P0 P1 P2 D0 D1 T T2 B P1 13mm ±�0.2 W LVK12 180mm ±3 A LVK12 LVK20 LVK24 LVK25 1.90 ±0.10 2.90 ±0.1 3.43 ±0.2 3.43 ±0.2 8.0 ±0.2 12.0 ±0.2 12.0 ±0.3 12.0 ±0.3 3.50 ±0.10 3.5 ±0.05 1.75 ±0.1 4.0 ±0.1 4.0 ±0.1 2.0 ±0.05 5.35 ±0.1 5.5 ±0.05 1.75 ±0.1 4.0 ±0.1 4.0 ±0.1 2.0 ±0.05 6.63 ±0.2 5.5 ±0.05 1.75 ±0.1 4.0 ±0.1 4.0 ±0.1 2.0 ±0.05 6.63 ±0.2 4.0 ±0.1 0.2 ±0.05 0.2 ±0.05 0.2 ±0.05 0.2 ±0.05 1.0 ±0.2 1.0 ±0.2 1000 1000 2.0 ±0.05 1.5 +0.1/-0 1.0 ±0.2 LVK25 4.0 ±0.1 1.5 +0.1/-0 1.5 +0.2/-0 1000 1.75 ±0.1 1.5 +0.1/-0 1.5 +0.2/-0 5000 60mm ±1 LVK20 LVK24 9mm ±0.3 (LVK12) 13mm ±0.3 (LVK 20, 24, 25) 5.5 ±0.05 1.5 +0.1/-0 1.0 +0.20/-0 Series Qty/Reel 1.5 +0.2/-0 1.0 ±0.2 ORDERIN G IN F ORMATION RoHS Compliant LVK25R005FER Series Case Size 12 = 1206 20 = 2010 24 = 2412 25 = 1224 Tolerance Tape & Reel Ohms R005 = 0.005 D = 0.5% F = 1% Standard values LVK12 LVK20 LVK24 1% Tolerance 0.01 0.01 0.01 0.012 0.012 0.015 0.015 0.02 0.02 0.02 0.024 0.027 0.025 0.03 0.03 0.03 0.033 0.033 0.039 0.039 0.039 0.047 0.047 0.05 0.05 0.05 0.075 0.075 0.10 0.10 LVK25 0.001 0.002 0.003 0.005 0.01 LVK12 LVK20 LVK24 0.5% Tolerance 0.01 0.01 0.01 0.015 0.015 0.02 0.02 0.02 0.025 0.025 0.03 0.03 0.03 0.033 0.033 0.039 0.05 0.05 0.05 0.075 0.10 0.10 LVK25 0.001 0.002 0.003 0.005 0.010 rev 3/18-1 14 1-866-9-OHMITE • Int’l 1-847-258-0300 • Fax 1-847-574-7522 • www.ohmite.com • [email protected]