General Note
IRC reserves the right to make changes in product specification without notice or liability.
All information is subject to IRC’s own data and is considered accurate at time of going to print. A subsidiary of
TT electronics plc
• 4222 South Staples Street • Corpus Christi Texas 78411 USA
Wire and Film Technologies Division
Telephone: 361 992 7900 • Facsimile: 361 992 3377 • Website: www.irctt.com
Low Cost Semi-Precision
Power Wirewound Resistor
LAS Series
• 1 and 3 watts
• 0.1 ohm to 18K ohms
• Color band identification
• ±5%, ±3%, ±1%, ±.5% tolerance
• Resistance wire TCR ±20 ppm/°C
• RoHS-compliant version available
Electrical Data
IRC
Type
Power Rating 275°C
Max. Hot Spot
Commercial Range
(ohms)
Non-Inductive Range
(ohms)
Available Resistance
(ohms)
125°C 25°C Min. Max. Min. Max. 0.5%, 1% 3%, 5%
LAS-1 1 2 0.1 7.5K 0.1 3.8K 1 - 7.5K 0.1 - 7.5K
LAS-3 2 3 0.1 18K 0.2 7.5K 1 - 18K 0.1 - 18K
Test Condition (@ 25°C) Max ∆R
Load Life 1000 hours 1.0%
Moisture Resistance 1.0%
Temperature Cycle 0.5%
Short Time Overload 0.5%
Low Temperature Operation 0.5%
Solder Heat 0.25%
Shock 0.5%
Vibration 0.5%
Environmental Data
LAS Series Issue October 2008 Sheet 1 of 3
LAS-3 Carbon Comp Replacement (contact factory)
The LAS-3 is a three watt conformal coated precision wirewound resistor. The resistance wire is welded to the end caps and
wound on alumina rod for good thermal conductivity. In circuit applications that utilize two watt carbon comp resistors the LAS-3
is an idead effective replacement. The LAS-3 5.6 ohm can be specifically designed to withstand 22 jooules of energy delivered
by a 1000 volt 10 x 1000 usec wave shape pulse.
Special LAS-3 5.6 ohm to 100 ohm will meet
Telecom GR-1089 lightning requirements.
• V = 1000 volts
• T1 = 10 usec rise
• T2 = 1000 usec to V2
• 10 ohm output impedance
MICROSECONDS
T2
LIGHTNING SURGE
T10
V2
V
• 4222 South Staples Street • Corpus Christi Texas 78411 USA
Wire and Film Technologies Division
Telephone: 361 992 7900 • Facsimile: 361 992 3377 • Website: www.irctt.com
Physical Data
Dimensions (Inches (mm))
IRC
Type A ±0.032 B (max) C (max) D (Lead Diameter) E (Lead length Min)
LAS-1 0.348 (8.84) 0.110 (2.80) 0.407 (10.34) 0.020 (0.53) 1.475 (37.5)
LAS-3 0.491 (12.47) 0.149 (3.80) 0.550 (13.99) 0.032 (0.81) 1.35 (34.3)
Low Cost Semi-Precision
Power Wirewound Resistor
A
C
B
D
E
Hot Spot Temperature @ 25°C
0 40 80 120 160 200
Percent of 25°C Power
Hot Spot Temperature (°C)
275
250
200
150
100
25
50
LAS3
LAS1
LAS1
Hot Spot Temperature @ 125°C
0 20 40 60 80 100
Percent of 125°C Power Rating
Hot Spot Temperature (°C)
275
250
225
200
175
125
150
LAS3
LAS Series Issue October 2008 Sheet 2 of 3
• 4222 South Staples Street • Corpus Christi Texas 78411 USA
Wire and Film Technologies Division
Telephone: 361 992 7900 • Facsimile: 361 992 3377 • Website: www.irctt.com
Sample Part No.
Type
LAS
Power
3 = 3 watts
1 = 1 watt
Resistance Value
Expressed in ohms
(Standard EIA/MIL Values)
Tolerance
J = ±5%, H = ±3%, F = ±1%, D = ±0.5%
Lead-Free Construction
Ordering Data
LAS - 3 2001 J LF
Pulse-Handling Capability @ 25°C
0.1 0.2 0.5 1 2 5 10
Resistance (ohms)
Energy (watts-second)
12
10
8
6
4
0
2
LAS3
LAS1
14
Low Cost Semi-Precision
Power Wirewound Resistor
25 75 125 175 225 275
200
175
150
125
100
75
Ambient Temperature (°C)
Percent of 125°C Power Rating
Power Derating Curve
LAS3
LAS1
LAS Series Issue October 2008 Sheet 3 of 3
