TOKEN
LRD Open Air Four-terminal Resistors
Four-terminal
Open Air Resistors
Token’s Open Air Four-terminal resistors (LRD)
tackle current sensing applications
Preview
Always preferred in current sense applications,
Token’s LRD Series range is available in the
1W, 3W, 5W, 7W and 10W packages,
resistance values down to 0.001 ohm,
with tolerances as tight as 0.50% and
TCRs of 50ppm standard.
The Kelvin (four-terminal) 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.
With up to 10W power rating and TCRs as low as 50ppm/°C, the LRD Series resistors deliver excellent
performance, making them ideal for a variety of applications. The resistor is constructed using a low-resistance,
low-inductance, high-impulse proprietary metal element that gives the device its extended power and temperature
ratings.
Continually upgrading its resistors to take advantage of modern technologies and manufacturing methods, Token
is now able to offer complete ranges of products which meet the RoHS requirements and in addition to detailing
these, the component selector also provides designers with a comprehensive selection of application notes.
The LRD devices can be manufactured to custom length/width for use as a current shunt. Token will also produce
outside these specifications to meet customer requirements. Contact us with your specific needs.
Features
- Low inductance.
- 4 leads for Kelvin connection.
- Decimal marked, silicone coated.
- Tinned copper terminal for easy soldering.
- Radial, self-supporting, design is ideal
for PC board mounting.
Applications
- Surge/Pulse Applications.
- Current Sensing Application.
- Feed Back & Motor Control.
- High Precision Measurement Instrumentation.
Version 2010
http://www.token.com.tw/
rfq token.com.tw
01 of 03
TOKEN
LRD Open Air Four-terminal Resistors
Specification & Dimensions (Unit: mm)
LSQ-A
L
W
H
P
d
Type
LRD-1
LRD-3
LRD-5
LRD-7
LRD-10
Rating Wattage
1W
3W
5W
7W
10W
Resistance Range (mΩ)
1 ~ 10 mΩ
1 ~ 10 mΩ
0.5 ~ 5 mΩ
0.3 ~ 3 mΩ
0.1 ~ 1 mΩ
Tolerance (%)
D(±0.5%)
F(±1%)
G(±2%)
J(±5%)s
TCR (ppm/°C)
±50 ppm/°C
±100 ppm/°C
Power Derating Curve
Power Derating Curve
120
Rated Load (%)
100
80
60
40
20
0
-55 -25
25 40
70
125
175
Ambient Temperature (℃)
02 of 03
http://www.token.com.tw/
rfq token.com.tw
Version 2010
TOKEN
LRD Open Air Four-terminal Resistors
KELVIN ELECTRICAL CONNECTION
Characteristic Specification
1
R
4
2
3
TERMINALS 2 & 3 CURRENT TRACES.
TERMINALS 1 & 4 SENSE TRACES.
Test Items
Operating Temperature Range
Maximum Working Voltage
Terminal Tensile Strength
Withstand Voltage
Short Time Overload
Thermal Shock
Load Life
Test Method
Specification
-55°C ~ 125°C
(P40°C x R)1/2
50N, 10s
ΔR≤±1.0%R
1000V, 1 Min.
No damage on the appearance.
5 times rated power, 5s
ΔR≤±4.0%R
-55°C~+125°C, 5 cycles, 30 min.
ΔR≤±5.0%R
70°C, 1000h 1.5 hours on, 0.5 hours off.
ΔR≤±5.0%R
How to Order
LRD
Part Number: LRD
Rated power
Code
1
3
5
7
10
5
R005
F
P
Tolerance %
Rated power
1 Watt
3 Watt
5 Watt
7 Watt
10 Watt
Code
Tolerance %
D
F
G
J
Package-Code
Code
±0.5%
±1%
±2%
±5%
Resistance Value (Ω)
Code
R005
Resistance Value (Ω)
Package-Code
R05
R1
0.005Ω
0.05Ω
0.1Ω
P
Bulk
Back to 1st Page - Open Air Four-terminal Resistors (LRD)
Version 2010
http://www.token.com.tw/
rfq token.com.tw
03 of 03
