BR Series
Bare Element Current Sense Resistor
Stackpole Electronics, Inc.
Resistive Product Solutions
Features:
•
•
•
•
•
•
•
•
•
•
•
•
•
1, 3 and 5 watts
±1%, ±2% or ±5% tolerance
±20 ppm/ºC element wire
±200 ppm/ºC at lead stops
All welded construction
Flameproof
Non-inductive (10nH max)
High current handling to 31 amps
RoHS compliant, lead-free and halogen-free
Current sensing
Feedback
Low inductance
Surge and pulse
Applications:
Electrical Specifications
Type / Code
BR1
BR3
BR5
Power Rating (Watts)
at 85ºC
1W
3W
5W
Ohmic Range (Ω) and Tolerance
1%, 2%, 5%
0.005 - 0.1
0.005 - 0.1
0.005 - 0.05
(1)
(1) Contact factory for resistance values below 0.005Ω.
Product photo shown above is typical. Actual components may vary depending on element wire size and amount of trim adjusting required to
meet desired resistance value.
Please refer to the High Power Resistor Application Note (page 3) for more information on designing and implementing
high power resistor types.
Mechanical Specifications
Element width varies depending on resistance value.
Type / Code
BR1
A
0.450 ± 0.040
11.43 ± 1.02
0.602 ± 0.040
15.30 ± 1.02
0.800 ± 0.040
20.32 ± 1.02
B
0.200 ± 0.100
5.08 ± 2.54
0.602 Typ - 1.000 Max
15.30 Typ - 25.40 Max
0.602 Typ - 1.000 Max
15.30 Typ - 25.40 Max
C
0.125 ± 0.030
3.18 ± 0.76
0.125 ± 0.030
3.18 ± 0.76
0.125 ± 0.030
3.18 ± 0.76
D
0.065 ± 0.010
1.65 ± 0.25
0.065 ± 0.010
1.65 ± 0.25
0.065 ± 0.010
1.65 ± 0.25
E
0.04 ± 0.002
1.02 ± 0.05
0.04 ± 0.002
1.02 ± 0.05
0.04 ± 0.002
1.02 ± 0.05
Unit
inches
mm
inches
mm
inches
mm
BR3
BR5
Rev Date: 06/28/2018
This specification may be changed at any time without prior notice
Please confirm technical specifications before you order and/or use.
1
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BR Series
Bare Element Current Sense Resistor
Stackpole Electronics, Inc.
Resistive Product Solutions
Performance Characteristics
Test
Moisture Resistance
Load Life @ 25ºC - 1,000 hours
Temperature Cycle @ -40ºC & +125ºC (1,000 cycles)
Test Specifications
±1%
±2%, + 0.0005Ω
±1%
Power Derating Curve:
100
-65ºC
85ºC
Percent Rated Power (%)
80
60
40
20
0
-80
0
50
100
150
200
250
300
350
400
Ambient Temperature (ºC)
Note: Maximum recommended solder joint/lead stop temperature = +105ºC
High Power Chip Resistors and Thermal Management
Stackpole has developed several surface mount resistor series in addition to our current sense resistors, which have had higher
power ratings than standard resistor chips. This has caused some uncertainty and even confusion by users as to how to reliably use
these resistors at the higher power ratings in their designs.
The data sheets for the RHC, RMCP, RNCP, CSR, CSRN, CSRF, CSS, and CSSH state that the rated power assumes an ambient
temperature of no more than 100°C for the CSS / CSSH series and 70°C for all other high power resistor series. In addition, IPC and
UL best practices dictate that the combined temperature on any resistor due to power dissipated and ambient air shall be no more
than 105°C. At first glance this wouldn’t seem too difficult, however the graph below shows typical heat rise for the CSR ½ 100
milliohm at full rated power. The heat rise for the RMCP and RNCP would be similar. The RHC with its unique materials, design,
and processes would have less heat rise and therefore would be easier to implement for any given customer.
Rev Date: 06/28/2018
This specification may be changed at any time without prior notice
Please confirm technical specifications before you order and/or use.
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marketing@seielect.com
BR Series
Bare Element Current Sense Resistor
Stackpole Electronics, Inc.
Resistive Product Solutions
The 102°C heat rise shown here would indicate there will be additional thermal reduction techniques needed to keep this part under
105°C total hot spot temperature if this part is to be used at 0.75 watts of power. However, this same part at the usual power rating
for this size would have a heat rise of around 72°C. This additional heat rise may be dealt with using wider conductor traces, larger
solder pads and land patterns under the solder mask, heavier copper in the conductors, via through PCB, air movement, and heat
sinks, among many other techniques. Because of the variety of methods customers can use to lower the effective heat rise of the
circuit, resistor manufacturers simply specify power ratings with the limitations on ambient air temperature and total hot spot
temperatures and leave the details of how to best accomplish this to the design engineers. Design guidelines for products in various
market segments can vary widely so it would be unnecessarily constraining for a resistor manufacturer to recommend the use of any
of these methods over another.
Note:
The final resistance value can be affected by the board layout and assembly process, especially the size of the mounting
pads and the amount of solder used. This is especially notable for resistance values ≤ 50mΩ. This should be taken into
account when designing.
RoHS Compliance
Stackpole Electronics has joined the worldwide effort to reduce the amount of lead in electronic components and to meet the various
regulatory requirements now prevalent, such as the European Union’s directive regarding “Restrictions on Hazardous Substances”
(RoHS 3). As part of this ongoing program, we periodically update this document with the status regarding the availability of our
compliant components. All our standard part numbers are compliant to EU Directive 2011/65/EU of the European Parliament as
amended by Directive (EU) 2015/863/EU as regards the list of restricted substances.
RoHS Compliance Status
Standard
Product
Series
BR
Description
Package /
Termination
Type
Special
Standard
Series
RoHS
Compliant
YES
Lead-Free Termination
Composition
Lead-Free
Mfg. Effective Date
(Std Product Series)
Jan-06
Lead-Free
Effective Date
Code
(YY/WW)
06/01
Open Air Bare Element
Current Sense Resistor
100% Matte Sn
“Conflict Metals” Commitment
We at Stackpole Electronics, Inc. are joined with our industry in opposing the use of metals mined in the “conflict region” of the
eastern Democratic Republic of the Congo (DRC) in our products. Recognizing that the supply chain for metals used in the
electronics industry is very complex, we work closely with our own suppliers to verify to the extent possible that the materials and
products we supply do not contain metals sourced from this conflict region. As such, we are in compliance with the requirements of
Dodd-Frank Act regarding Conflict Minerals.
Compliance to “REACH”
We certify that all passive components supplied by Stackpole Electronics, Inc. are SVHC (Substances of Very High Concern) free
and compliant with the requirements of EU Directive 1907/2006/EC, “The Registration, Evaluation, Authorization and Restriction of
Chemicals”, otherwise referred to as REACH. Contact us for complete list of REACH Substance Candidate List.
Environmental Policy
It is the policy of Stackpole Electronics, Inc. (SEI) to protect the environment in all localities in which we operate. We continually
strive to improve our effect on the environment. We observe all applicable laws and regulations regarding the protection of our
environment and all requests related to the environment to which we have agreed. We are committed to the prevention of all forms
of pollution.
Rev Date: 06/28/2018
This specification may be changed at any time without prior notice
Please confirm technical specifications before you order and/or use.
3
www.seielect.com
marketing@seielect.com
BR Series
Bare Element Current Sense Resistor
Stackpole Electronics, Inc.
Resistive Product Solutions
How to Order
1
2
3
4
5
6
7
8
9
B
R
1
F
B
1
0
L
0
Product Series
Code
Description
BR
Current Sense
Power Rating
Code Power
1W
1
3W
3
5W
5
Tolerance
Code Tol
1%
F
2%
G
5%
J
Code
B
Packaging
Description
Size
Bulk
All Sizes
Quantity
1,000
Resistance Value
Four characters with the
multiplier used as the
decimal holder.
"L" used as multiplier
of 10
-3
for any value
under 0.1 ohm.
0.005 ohm = 5L00
0.05 ohm = 50L0
0.1 ohm = R100
Rev Date: 06/28/2018
This specification may be changed at any time without prior notice
Please confirm technical specifications before you order and/or use.
4
www.seielect.com
marketing@seielect.com
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