IRC Wire and Film Technologies Division
General Note
A subsidiary of
TT electronics plc
CMO Series Issue February 2007
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 printing.
© IRC Wire and Film Technologies Division
Telephone: 828 264 8861 • Facsimile: 828 264 8866 • Website: www.irctt.com
• 736 Greenway Road Boone, North Carolina 28607-1860
Specifications
• Power ratings from 1/4W to 9W
• Stable performance in harsh environments
• Superior flame retardant coating
• High purity ceramic core
• Meets EIA-RC2655A requirements
• Non-inductive type available
CMO Series
Commercial Grade Metal Oxide Resistor
IRC Type Power
Rating at
70°C (W)
Resistance
Range*
(Ohms)
Tolerance
(±%)
TCR
(±ppm/ºC)
Max.
Working
Voltage (V)
Max.
Overload
Voltage (V)
Dielectric
Withstanding
Voltage (V)
Standard Size
CMO-1/4 0.25 0.3 - 50K 2, 5, 10
350
250 400 250
CMO-1/2 0.5 0.3 - 50K 2, 5, 10 250 400 250
CMO-1 1 0.3 - 50K 2, 5, 10 350 600 350
CMO-2 2 0.3 - 50K 2, 5, 10 350 600 350
CMO-3 3 5 - 100K 2, 5, 10 500 800 500
CMO-5 5 5 - 150K 2, 5, 10 750 1000 750
CMO-7 7 20 - 150K 2, 5, 10 750 1000 750
CMO-8 8 30 - 200K 2, 5, 10 750 1000 750
CMO-9 9 50 - 200K 2, 5, 10 750 1000 750
Miniature Size
CMO-1/2S 0.5 0.3 - 50K 2, 5, 10
350
250 400 250
CMO-1S 1 0.3 - 50K 2, 5, 10 350 600 350
CMO-2S 2 0.3 - 50K 2, 5, 10 350 600 350
CMO-3S 3 0.3 - 50K 2, 5, 10 350 600 350
CMO-5SS 5 5 - 100K 2, 5, 10 500 800 500
CMO-5S 5 5 - 150K 2, 5, 10 500 800 500
IRC Wire and Film Technologies Division
General Note
A subsidiary of
TT electronics plc
CMO Series Issue February 2007
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 printing.
© IRC Wire and Film Technologies Division
Telephone: 828 264 8861 • Facsimile: 828 264 8866 • Website: www.irctt.com
• 736 Greenway Road Boone, North Carolina 28607-1860
Environmental Performance
Short-time overload Standard Size, ∆R/R ≤ (±1%+0.05Ω), with no evidence of mechanical damage.
Miniature Size, ∆R/R ≤ (±2%+0.05Ω), with no evidence of mechanical damage.
Dielectric withstanding voltage No evidence of flashover, mechanical damage, arcing or insulation breakdown.
Pulse overload Standard Size, ∆R/R ≤ (±2%+0.05Ω), with no evidence of mechanical damage.
Miniature Size, ∆R/R ≤ (±5%+0.05Ω), with no evidence of mechanical damage.
Terminal strength No evidence of mechanical damage.
Resistance to Soldering heat ∆R/R ≤ (±1%+0.05Ω), with no evidence of mechanical damage.
Solderability Minimum 95% coverage.
Resistance to solvent No deterioration of protective coating and markings.
Temperature cycling ∆R/R ≤ (±2%+0.05Ω), with no evidence of mechanical damage.
Humidity (Steady state) ∆R/R ≤ (±2%+0.05Ω), with no evidence of mechanical damage.
Load life in humidity ∆R/R: ≤ ±5% for <100KΩ; ±10% for ≥100KΩ.
Load life ∆R/R: ≤ ±5% for <100KΩ; ±10% for ≥100KΩ.
Flame retardant No evidence of flaming or arcing.
CMO Series
Commercial Grade Metal Oxide Resistor
General Note
A subsidiary of
TT electronics plc
CMO Series Issue February 2007
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 printing.
© IRC Wire and Film Technologies Division
Telephone: 828 264 8861 • Facsimile: 828 264 8866 • Website: www.irctt.com
• 736 Greenway Road Boone, North Carolina 28607-1860
IRC Wire and Film Technologies Division
CMO Series
Commercial Grade Metal Oxide Resistor
Dimensions (mm)
• Standard gray base color for standard size product; Blue color for miniature size product
• Standard non-flammable coating
H L H
D
Od
IRC Type D (max.) L (max.) d (±0.02) H (±3)
Standard Size CMO-1/4 2.5 7.5 0.6 28
CMO-1/2 4.0 10.0 0.6 28
CMO-1 5.0 12.0 0.7 28
CMO-2 5.5 16.0 0.8 28
CMO-3 6.5 17.5 0.8 28
CMO-5 8.5 26.0 0.8 38
CMO-7 8.5 32.0 0.8 38
CMO-8 8.5 41.0 0.8 38
CMO-9 8.5 54.0 0.8 38
Miniature Sizes CMO-1/2S 3.0 7.5 0.6 28
CMO-1 4.5 10.0 0.7 28
CMO-2 5.0 12.0 0.7 28
CMO-3 5.5 16.0 0.8 28
CMO-5SS 6.5 17.5 0.8 28
CMO-5S 8.0 25.0 0.8 38
IRC Wire and Film Technologies Division
General Note
A subsidiary of
TT electronics plc
CMO Series Issue February 2007
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 printing.
© IRC Wire and Film Technologies Division
Telephone: 828 264 8861 • Facsimile: 828 264 8866 • Website: www.irctt.com
• 736 Greenway Road Boone, North Carolina 28607-1860
Ordering Data
Sample Part No. CMO 2 1001 J LF AMMO
IRC Type
Power rating
(See specs table)
Resistance Value (EIA 4-digit code)
(≥100Ω - First 3 significant digits
plus 4th digit multiplier)
Example: 100Ω = 1000;
1000Ω = 1001
150KΩ = 1503
(>
100
Ω - “R” is used to
designate decimal)
Example:
10Ω = 51R0;
1Ω = 1R00
0.25Ω = R250
Tolerance (EIA format)
G = ±2%
J = ±5%
K = ±10%
RoHS- compliance
LF = RoHS compliant construction
Packaging
BLK = bulk packaging
AMMO = ammo packaging
LT = lead tape
TR = tape and reel
Temperature Rise Chart
Rated load (%)
Temperature rise (C)
250
200
150
100
50
0
7W, 8W, 9W
5W
3W
2W
1W
1/4W, 1/2W
25 50 75
-55°C
Derating Curve
100
80
60
40
20
0
70°C
MOR 1/4W~1/2W
CMO 1/4W-1/2W
MOR 1W~9WCMO 1W-9W
130°C 235°C
Ambient temperature (°C)
Percent rated load (%)
-60 -40 -20 0 20 40 60 80 100 120 140 160 180 200 240
Performance Curves
Specify type, resistance, tolerance, RoHS-Compliance
and packaging. This example is for a Metal Oxide Resistor,
2-watt, 1000Ω resistor.
