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 cali-
brated 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)
FeatureS
facilitates a very accurate current measurement. Ohmites pro-
Designed for automatic insertion
prietary technology offers an excellent Temperature Coefficient
of Resistance (TCR) even for very low resistance values. The Industr y standard sizes
resistive element consists of a durable, anti-corrosive metal
High-precision Kelvin connect capability
alloy that combines reliable performance with the ability to
in a small package
withstand harsh environments.
SerieS SpeciFicationS
Power Resistance Max. Over Current
Pkg. Rating Range TCR Available Max. Max.
Series Size (W @70C) () (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, 9,10m 150W 200A
0.005-0.01 100ppm
characteriSticS
Res. Range 0.001 - 0.010
Operating Temp. Range -40C to +125C
+70C
Rated Ambient Temperature
Resistance Tolerance 0.5% and 1% standard
Temperature Coefficient LVK12, LVK20, LVK24: 50ppm standard
LVK25: 100ppm, 200ppm, or 300ppm based on
resistance value
Coating Material epoxy resin
100% matte tin
Terminals
Max. Over Current Time applied: 10ms max.
Interval: 60sec min.
Max. over current = (Max. power Resistance
value) or max. current, whichever is smaller.
Storage conditions Temperature: 5C ~ 35C
Humidity: 25% ~ 70%
12 1-866-9-OHMITE Intl 1-847-258-0300 Fax 1-847-574-7522 www.ohmite.com info@ohmite.comLVK Series
Four Terminal High Precision Current Sense
perFormance characteriSticS
Test Items Performance Requirements Test Methods / standard: JIS C 5201.1
(0.5%+0.0005) Rated voltage x 1.5 for 5s
Overload
Endurance at 70C (0.5%+0.0005) 70C3C, Rated voltage 1.5h ON, 0.5h OFF, 1000h
Moisture (0.5%+0.0005) 60C2C, 90%~95% RH, Rated voltage 1.5h ON,
resistance 0.5h OFF, 1000h
(0.5%+0.0005) -40C (30min.)/+125C (30min.), 5 cycles
Rapid change of
temperature
Resistance to sol- (0.5%+0.0005) 260C5C for 10s1s
dering heat
Substrate bending (0.5%+0.0005) Bending width: 2mm for 10s1s, Glass epoxy sub-
strate with thickness of 1.6mm
Solderability 95% or more of the electrode surface 245C5C for 3s0.5s
shall be covered with new solder
Reflow Temperature Profile
300
For lead free soldering (Sn-Ag-Cu solder)
Peak 240 ~ 260 Max. 10s
250
Preheating: 130 ~ 180 60s ~ 90s Ramp-up rate: max 3C/sec.
200
Heating: Over 220 30s ~ 90s
Time above liquidous: 60 150 sec.
Heating
Peak: 240 ~ 260 Max. 10s Ramp-down rate: max 6C/sec.
150
Over 220
30s ~ 90s
Preheating
Max. number of reflow: 2
100 130 ~ 180
60 ~ 90 sec.
50
Time (sec.)
dimenSionS
(mm)
L
LVK25
(2 watt)
W
LVK 12, LVK20, LVK24
(0.5, 0.75 & 1 watt)
L
Schematic
VV
2
W
t II
V = sensing terminal
a
(voltage)
4
I = current terminal
t
b
Layout for illustra-
1. Electrode
a 3
tion only, part can be
2. Protection
rotated 180 without
b
coat
effect to the circuit.
1 3. Almina
substrate
4. Resistor
Size L W t a b
LVK12 (1206) 3.2 0.2 1.6 0.2 0.5 0.15 1.0 0.2 0.55 0.2
LVK20 (2010) 5.0 0.2 2.5 0.2 0.5 0.15 1.7 0.2 0.9 0.2
LVK24 (2412) 6.4 0.2 3.2 0.2 0.5 0.15 2.1 0.2 1.2 0.2
LVK25 (1224) 3.2 0.2 6.4 0.2 0.5 0.2 0.4 0.2 2.7 0.2
1-866-9-OHMITE Intl 1-847-258-0300 Fax 1-847-574-7522 www.ohmite.com info@ohmite.com 13
Temperature C