73M1A, 73M2A, 73M3x & 73M5 Series
Current Sensing Resistor – Up To 5 Watts
Features
Metal Plate Construction – Copper Alloy
1 – 5 Watts Power Rating @ +70°C
Resistance Range 0.25 – 120 milliohms
Operating Temperature to +155°C
EIA Standard Package Sizes
Terminal Finish – Matte Tin [e3]
Reflow Capable per JEDEC J-STD-020, +260°C Maximum
Tape and Reel Packaging
Applications
Current Detection
Current Limiting
Regulated Battery Circuits
Motor Control
Power Supply
Hard Disk Drives
Inverter/Converter
Industrial Equipment
Infotainment Systems
Description
73M1A, 73M2A, 73M3x and 73M5 Series Current Sensing Resistors are metal plate packaged devices that
provides excellent accuracy for current detection. Each resistor has good electrical and thermal characteristics by
using a special metallic resistor material.
Ordering Information
Res i s tor
V a l ue
R00025
Model
73M
1A
Code
1A
2A
3A
3B
5
Type
1 Watt Rating
2 Watt Rating
3 Watt Rating
3 Watt Rating
5 Watt Rating
Code
R00025
Res i s tor
T ol era nce
F
2
Resistor Value
0.25 milliohms
Code
F
Tolerance
±1%
Notes:
1. No dashes or spaces to appear in part number.
2. Resistor codes are 4, 5 or 6 characters. See Addendum for Standard EIA Values and Codes.
N ot a l l perf orm a nce com bi na ti ons a nd res i s tor va l ues m a y be a va i l a bl e.
Conta ct your l oca l CT S Repres enta ti ve or CTS Cus tom er Servi ce f or a va i l a bi l i ty.
This product is specified for use only in standard commercial applications. Supplier disclaims all express and implied warranties
and liability in connection with any use of this product in any non-commercial applications or in any application that may
expose the product to conditions that are outside of the tolerances provided in its specification.
DOC# 008-0542-0 Rev. B
Page 1 of 6
©2017 CTS® Corporation. Information/product(s) subject to change. No warranty that product(s) will meet the stated specifications for customer specific applications or test
equipment. Visit www.ctscorp.com for list of applicable patent(s), more information, or to request a quote.
73M1A, 73M2A, 73M3x & 73M5 Series
Current Sensing Resistor – Up To 5 Watts
Ordering Information
Part Number Examples
T ol era nce/V a l ue
1.5 m i l l i ohm s
0.25 m i l l i ohm s
50 m i l l i ohm s
120 m i l l i ohm s
Res i s tor Code
F [ ±1%]
73M2AR0015F
73M3AR00025F
73M3BR050F
73M5R120F
Electrical & Environmental Specifications
Operating Conditions
Mo d el
Typ e
R at ed
P o w er
[W at t s]
R esist an c e
R an ge
[m Ω]
Resist o r
To ler an c e
[% ]
Tem p er at u r e
C o effic ien t
R at ed Am b ien t
Tem p er at u r e
Op er at in g
Tem p er at u r e
R an ge
7 3 M1 A
1.0
1 - 50
±1
R ≥ 0.010Ω: ±50ppm/°C
R < 0.010Ω: ±100ppm/°C
+70°C
-55°C to +155°C
7 3 M2 A
2.0
1 - 75
±1
R < 0.010Ω: ±100ppm/°C
R ≥ 0.010Ω: ±50ppm/°C
+70°C
-55°C to +155°C
7 3 M3 A
3.0
0.25 - 3
±1
R ≤ 0.001Ω: ±200ppm/°C
R > 0.001Ω: ±100ppm/°C
+70°C
-55°C to +155°C
7 3 M3 B
3.0
4 - 100
±1
±50ppm/°C
+70°C
-55°C to +155°C
7 3 M5
5.0
1 - 120
±1
R < 0.010Ω: ±100ppm/°C
R ≥ 0.010Ω: ±50ppm/°C
+70°C
-55°C to +155°C
Power Derating Curve 73M1A, 73M2A, 73M3A, 73M3B – Typical
With the rated ambient temperature set to +70°C, the maximum power [maximum current for 0Ω product] at a temperature of no more
than rated ambient temperature shall be equal to the rated power [rate current for 0Ω product]. The maximum power at a temperature
exceeding the rated ambient temperature shall be a value determined by reducing the rated power according to the power reduction
curve in the figure below.
DOC# 008-0542-0 Rev. B
Page 2 of 6
©2017 CTS® Corporation. Information/product(s) subject to change. No warranty that product(s) will meet the stated specifications for customer specific applications or test
equipment. Visit www.ctscorp.com for list of applicable patent(s), more information, or to request a quote.
73M1A, 73M2A, 73M3x & 73M5 Series
Current Sensing Resistor – Up To 5 Watts
Electrical & Environmental Specifications
Power Derating Curve 73M5 – Typical
With the rated ambient temperature set to +105°C, the maximum power [maximum current for 0Ω product] at a temperature of no more
than rated ambient temperature shall be equal to the rated power [rate current for 0Ω product]. The maximum power at a temperature
exceeding the rated ambient temperature shall be a value determined by reducing the rated power according to the power reduction
curve in the figure below.
Rated Voltage
The rated voltage shall be the DC or AC [effective power frequency] voltage corresponding to the rated power and shall be determined
with the formula shown below. If the determined rated voltage exceeds the maximum operating voltage specified in Operating Conditions
table, the maximum operating voltage shall be the rated voltage.
E = Rated Voaltge [V]
E = √ PxR
P = Rated Power [W]
R = Nomimal Resistance [Ω]
Environmental Parameters
Max im u m D elt a R [% ]
Test
Test D esc r ip t io n
7 3 M1 A, 7 3 M2 A, 7 3 M3 A, 7 3 M3 B , 7 3 M5
R esist an c e
±1.0
±50ppm/°C, ≥ 10mΩ
±100ppm/°C, ≥ 1mΩ
±50ppm/°C
Tem p er at u r e C o effic ien t
Sh o r t -Tim e Ov er lo ad
I n su lat io n R esist an c e
D ielec t r ic W it h st an d in g Vo lt age
R esist an c e t o So ld er H eat
So ld er ab ilit y
±100ppm/°C, < 10mΩ [73M1A, 73M2A, 73M5]
±200ppm/°C, < 1mΩ [73M3A]
±50ppm/°C
[73M3B]
±0.5
±2.0
9
Over 10 ohm
No Breakdown
±0.5
No Damage
Over 95%
Coverage
Vib r at io n
±0.5
No Damage
R esist an c e t o So lven t
No Damage
H igh Tem p er at u r e Ex p o su r e
C h an ge o f Tem p er at u r e
Measurement current; 1A measured at +25°C [73M3A - 1A above 1mohm; 3A 1mohm or less]
[73M1A, 73M2A, 73M5]
[73M3A]
[73M3B]
±2.0
±0.5
No Damage
[73M1A, 73M2A, 73M3x]
[73M5]
Standard temperature at +25°C
Measured temperature at +150°C
Applied electric power equal to 3 times rated power in 5s [JIS C 5201-1 4.13]
Measured at terminals and center of resistor by D.C. 100V ±15V in 1 minute [JIS C 5201-1 4.6]
Applied at terminals and center of resistor on A.C. 500V, 1 minute [JIS C 5201-1 4.7]
Place on copper sheet [t = 0.2mm] heated by solder, +260°C ±5°C, 5 ±0.5 seconds
Immerse terminal in solder [Sn3Ag0.5Cu], +245°C ±0.5°C, 3 ±0.5 seconds [JIS C 5201-1 4.17]
Frequency 10Hz to 55Hz, Pk-Pk amplitude 15mm, sweeping rate 1 minute,
3 directions each 2 hours [JIS C 5201-1 4.22]
Immerse in Isopropyl alcohol, +20°C to +25°C, 60 ±5 seconds
1,000 hours @ +155°C ±2°C, bias load 0% power [JIS C 5201-1 4.23.2]
30 minutes @ -55°C, 3 minutes @ +25°C, 30 minutes @ +155°C, 3 minutes @ +25°C; 5 cycles
Mo ist u r e Resist an c e
±1.0
MIL-STD-202, Method 106, 0% power 7a and 7b not required, 1 cycle = 24 hours, 10 cycles
B ias H u m id it y
±1.0
1,000 hours @ +85°C ±2°C, 85% relative humidity, bias load 10%, on time 90 minutes/off time 30 minutes
En d u r an c e [Rat ed L o ad ]
±2.0
1,000 hours @ +70°C ±3°C, bias load, on time 90 minutes/off time 30 minutes
DOC# 008-0542-0 Rev. B
Page 3 of 6
©2017 CTS® Corporation. Information/product(s) subject to change. No warranty that product(s) will meet the stated specifications for customer specific applications or test
equipment. Visit www.ctscorp.com for list of applicable patent(s), more information, or to request a quote.
73M1A, 73M2A, 73M3x & 73M5 Series
Current Sensing Resistor – Up To 5 Watts
Mechanical Specifications
Package Drawing/Dimensions
Mo d el
Ty p e
D im en sio n s
[m m ]
Resist an c e
[m Ω]
L
W
t
c
7 3 M1 A
3.2 ±0.3
1.6 ±0.3
0.6 ±0.3
0.5 ±0.3
-
7 3 M2 A
6.3 ±0.3
3.2 ±0.3
0.8 ±0.3
1.9 ±0.3
1.0 - 4.0
0.6 ±0.3
1.1 ±0.3
1.3 Max.
1.4 Max.
7 3 M3 A
6.8 ±0.3
6.5 ±0.3
7 3 M3 B
7 3 M5
6.7 ±0.3
11.4 ±0.3
7.2 ±0.3
6.9 ±0.3
2.2 ±0.3
1.3 Max.
1.2 Max.
1.3 Max.
1.8 Max.
4.1 - 75
0.25, 0.50
1.0
1.5
1.8 ±0.3
2.0
1.6 ±0.3
2.5
1.3 ±0.3
3.0
1.1 ±0.3
-
3.2 ±0.3
1.0 - 5.0
1.8 ±0.3
5.1 - 120
Notes
1. Terminal Details
Base Metal – Copper [Cu]
Barrier Plating – Nickel [Ni]
Finish Plating – Matte Tin [Sn]
Recommended Pad Layout
Mo d el
Ty p e
7 3 M1 A
7 3 M2 A
7 3 M3 A
7 3 M3 B
7 3 M5
A
D im en sio n s
[m m ]
B
C
2.1
1.4
1.6
-
2.8
1.9
1.0 - 4.0
2.0
3.5
4.1 - 75
3.8
1.4
0.25 - 1.5
3.4
2.2
2.0
3.2
2.6
2.5
2.9
3.2
3.0
2.7
3.5
-
4.8
4.0
1.0 - 5.0
3.4
6.8
5.1 - 120
3.7
7.1
7.8
7.5
DOC# 008-0542-0 Rev. B
Resist an c e
[m Ω]
Page 4 of 6
©2017 CTS® Corporation. Information/product(s) subject to change. No warranty that product(s) will meet the stated specifications for customer specific applications or test
equipment. Visit www.ctscorp.com for list of applicable patent(s), more information, or to request a quote.
73M1A, 73M2A, 73M3x & 73M5 Series
Current Sensing Resistor – Up To 5 Watts
Mechanical Specifications
Marking Information
Mo d el
Ty p e
P ar t Mar k in g
Rxxx = "R" is the decimal point and 3 digits [E24] are significant values. See resistor tables for codes.
7 3 M1 A
Rxxx = "R" is the decimal point and 3 digits [E24] are significant values. See resistor tables for codes.
7 3 M2 A
Nominal resistances that includes a decimal point; marking is denoted by "m" expressing a decimal point in milliohms and three digits.
Ex. 1m50 [1.5 milliohms]
Rxxx = "R" is the decimal point and 3 digits [E24] are significant values. See resistor tables for codes.
7 3 M3 A
7 3 M3 B
Nominal resistances that includes a decimal point; marking is denoted by "m" expressing a decimal point in milliohms and three digits.
Ex. 0m25 [0.25 milliohms]
Rxxx = "R" is the decimal point and 3 digits [E24] are significant values. See resistor tables for codes.
7 3 M5
Packaging
Tape and Reel Information
Embossed Tape
Mo d el
Ty p e
[mm]
W
P1
E
F
Do
Po
P2
Ao
Bo
Ko
t
7 3 M1 A
8.0 ±0.15
4.0 ±0.1
1.75 ±0.10
3.5 ±0.1
1.55 ±0.05
4.0 ±0.1
2.0 ±0.1
1.83 ±0.10
3.48 ±0.10
0.9 ±0.1
0.20 ±0.05
7 3 M2 A
12.0 ±0.15
4.0 ±0.1
1.75 ±0.10
5.5 ±0.1
1.55 ±0.05
4.0 ±0.1
2.0 ±0.1
3.50 ±0.10
6.74 ±0.10
1.1 ±0.1
0.20 ±0.05
7 3 M3 A
12.0 ±0.15
8.0 ±0.1
1.75 ±0.10
5.5 ±0.1
1.50 ±0.05
4.0 ±0.1
2.0 ±0.1
6.75 ±0.10
7.15 ±0.10
1.7 ±0.1
0.25 ±0.05
7 3 M3 B
12.0 ±0.15
12.0 ±0.1
1.75 ±0.10
5.5 ±0.1
1.55 ±0.05
4.0 ±0.1
2.0 ±0.1
7.70 ±0.10
7.15 ±0.10
1.2 ±0.1
0.25 ±0.05
7 3 M5
24.0 ±0.30
12.0 ±0.1
1.75 ±0.10
11.5 ±0.1
1.55 ±0.05
4.0 ±0.1
2.0 ±0.1
7.20 ±0.10 11.80 ±0.10
1.7 ±0.1
0.30 ±0.10
Reel
[mm]
Mo d el
Ty p e
Qu an t it y
P er Reel
W
M
A
B
C
D
7 3 M1 A
4,000
12.0 ±0.5
178 ±0.1
2.0 ±0.5
13.2 ±0.5
21.7 ±0.5
60.0 ±0.5
7 3 M2 A
4,000
16.2 ±0.5
178 ±0.1
2.5 ±0.6
13.5 ±0.6
21.9 ±0.6
60.0 ±0.5
7 3 M3 A
1,000
16.2 ±0.5
178 ±0.1
2.5 ±0.6
13.5 ±0.6
21.9 ±0.6
60.0 ±0.5
7 3 M3 B
1,000
16.2 ±0.5
178 ±0.1
2.5 ±0.6
13.5 ±0.6
21.9 ±0.6
60.0 ±0.5
7 3 M5
500
24.4 +2.0 -0.0 178 ±0.1
2.5 ±0.6
13.5 ±0.6
21.9 ±0.6
60.0 ±0.5
DOC# 008-0542-0 Rev. B
Page 5 of 6
©2017 CTS® Corporation. Information/product(s) subject to change. No warranty that product(s) will meet the stated specifications for customer specific applications or test
equipment. Visit www.ctscorp.com for list of applicable patent(s), more information, or to request a quote.
73M1A, 73M2A, 73M3x & 73M5 Series
Current Sensing Resistor – Up To 5 Watts
Addendum
Standard EIA Codes and Resistor Values - E-24 [4, 5, 6-Digit Resistor Code for F Tolerances]
C OD E
OH MS
COD E
OH MS
C OD E
OH MS
COD E
OH MS
R00025
0.00025
R009
0.00900
R030
0.03000
R082
0.08200
R0005
0.00050
R010
0.01000
R033
0.03300
R091
0.09100
R001
0.00100
R011
0.01100
R036
0.03600
R100
0.10000
R0015
0.00150
R012
0.01200
R039
0.03900
R110
0.11000
R002
0.00200
R013
0.01300
R043
0.04300
R120
0.12000
R0025
0.00250
R015
0.01500
R047
0.04700
R003
0.00300
R016
0.01600
R050
0.05000
R004
0.00400
R018
0.01800
R051
0.05100
R005
0.00500
R020
0.02000
R056
0.05600
R006
0.00600
R022
0.02200
R062
0.06200
R007
0.00700
R024
0.02400
R068
0.06800
R008
0.00800
R027
0.02700
R075
0.07500
DOC# 008-0542-0 Rev. B
Page 6 of 6
©2017 CTS® Corporation. Information/product(s) subject to change. No warranty that product(s) will meet the stated specifications for customer specific applications or test
equipment. Visit www.ctscorp.com for list of applicable patent(s), more information, or to request a quote.