# Understanding the CSM series shunt resistors from Bourns

This applies to the four sizes CSM2F-6918, CSM2F-7036, CSM2F-8518, CSM2F-8536

There are three different broad categories of Current Sense Measurement Shunts separated by the presence or absence of pins and how the part is finished.

Navigating the available options if you are not starting with the right document can be challenging since the data sheets are individual instead of series based. Because of this, I hope this can help shed some light on how it all works.

### The CSM Series from Bourns.

Looking at the part numbers a pattern does emerge.

CSM = This is the base series number
2F = This is the number of terminals and style code
8518 = This is the size code. Options are 6918, 7036, 8518, 8536
L050 = Resistance code. See Chart Below
J = Tolerance rating. This is 5% across the series and represented by J
x1 = See chart below
x2 = See chart below

Size Wattage
6918 36W
7036 50W
8518 36W
8536 50W

### Resistance Code

This is represented in Milliohms. The “L” represents a decimal point. Different resistor values are available depending if the part does or does not have sense pins as well as which series it belongs.

Without sense pins

6918 7036 8518 8536
0 50
100
200
25
50
100
50
100
200
25
50
100
1 50 50 50
100
25
50
2 50
100
200
25
50
100
50
100
200
25
50
100

With sense pins

6918 7036 8518 8536
0 50
100
200
25
50
100
50
100
200
25
50
100
1 50 50 50 25
50
2 50
100
200
25
50
100
50
100
200
25
50
100

## x1 options

Without Sense Pins With Sense Pins
Packaging Options Number of Pins
0 = Bulk Pack
T = Tray Pack
2 = 2 Pins
3 = 3 Pins

## x2 options

Surface Finishing
0 = Bare Copper Terminals
1 = Tinned Terminals
2 = Fully Tinned Terminals and Resistive Element

These products can all be found on the Digikey website. Click the link below to see them.
https://www.digikey.com/en/products/filter/specialized-resistors/55

ProductExamples

## Current Sense Resistors w/Bare Copper Terminals

MFR PART # CSM2F-8518-L050J00
DIGI-KEY PART # 118-CSM2F-8518-L050J00-ND
MANUFACTURER Bourns Inc.
DESCRIPTION 50 µOhms ±5% 36W Shunt, Battery Specialized Resistor ±100ppm/°C Surface Mount

MFR PART # CSM2F-8518-L050J20
DIGI-KEY PART # 118-CSM2F-8518-L050J20-ND
MANUFACTURER Bourns Inc.
DESCRIPTION 50 µOhms ±5% 36W Shunt, Battery Specialized Resistor ±100ppm/°C Through Hole

## Current Sense Resistor w/Tinned Terminals

MFR PART # CSM2F-8518-L050J01
DIGI-KEY PART # CSM2F-8518-L050J01-ND
MANUFACTURER Bourns Inc.
DESCRIPTION 50 µOhms ±5% 36W Specialized Resistor ±150ppm/°C Surface Mount

MFR PART # CSM2F-8518-L050J21
DIGI-KEY PART # 118-CSM2F-8518-L050J21-ND
MANUFACTURER Bourns Inc.
DESCRIPTION 50 µOhms ±5% 36W Shunt, Battery Specialized Resistor ±150ppm/°C Through Hole

## Current Sense Resistors / Fully Tinned

MFR PART # CSM2F-8518-L050J02
DIGI-KEY PART # 118-CSM2F-8518-L050J02-ND
MANUFACTURER Bourns Inc.
DESCRIPTION 50 µOhms ±5% 36W Shunt, Battery Specialized Resistor ±200ppm/°C Surface Mount

MFR PART # CSM2F-8518-L050J22
DIGI-KEY PART # 118-CSM2F-8518-L050J22-ND
MANUFACTURER Bourns Inc.
DESCRIPTION 50 µOhms ±5% 36W Shunt, Battery Specialized Resistor ±200ppm/°C Through Hole

### Custom Options are available from Bourns

Can be right angle or vertical, with a variety of different connector options. It should be noted that using a 4-wire connection for parts with such a low resistance value is key due to the very low value.

#### Shunt Resistor with Sense Pins, Bare Copper Terminals, and PCB connector.

AEC Q200 Qualified Resistors from Bourns

Accurate Measurements using Shunt Resistors and Current Sense Modules in High-Energy Storage Applications

applicable part numbers

CSM2F-7036-L050J01
CSM2F-8518-L050J20
CSM2F-8518-L100J21
CSM2F-8518-L100J01
CSM2F-8518-L050J31
CSM2F-8536-L025J30
CSM2F-8536-L050J21
CSM2F-8536-L050J20
CSM2F-8518-L050J01
CSM2F-6918-L050J01
CSM2F-6918-L050J00
CSM2F-6918-L050J02
CSM2F-8518-L050J00
CSM2F-8518-L050J02
CSM2F-6918-L100J00
CSM2F-8518-L100J02
CSM2F-6918-L100J02
CSM2F-8518-L200J02
CSM2F-8518-L200J00
CSM2F-6918-L200J02
CSM2F-6918-L200J00
CSM2F-7036-L025J00
CSM2F-7036-L025J02
CSM2F-8536-L025J02
CSM2F-8536-L050J01
CSM2F-8536-L025J01
CSM2F-7036-L050J00
CSM2F-8536-L050J00
CSM2F-8536-L025J00
CSM2F-8536-L050J02
CSM2F-7036-L050J02
CSM2F-7036-L100J02
CSM2F-8536-L100J02
CSM2F-7036-L100J00
CSM2F-8536-L100J00
CSM2F-6918-L100J30
CSM2F-8518-L100J30
CSM2F-8518-L050J30
CSM2F-6918-L050J30
CSM2F-6918-L050J22
CSM2F-6918-L100J22
CSM2F-6918-L200J30
CSM2F-8518-L100J22
CSM2F-8518-L050J22
CSM2F-6918-L100J20
CSM2F-6918-L050J20
CSM2F-6918-L200J20
CSM2F-8518-L100J20
CSM2F-6918-L050J21
CSM2F-8518-L050J32
CSM2F-6918-L200J22
CSM2F-8518-L100J32
CSM2F-6918-L050J32
CSM2F-8518-L050J21
CSM2F-6918-L100J21
CSM2F-6918-L100J32
CSM2F-8518-L100J31
CSM2F-6918-L050J31
CSM2F-6918-L100J31
CSM2F-6918-L200J32
CSM2F-6918-L050JT1
CSM2F-8518-L200J20
CSM2F-7036-L025J30
CSM2F-8518-L200J30
CSM2F-8518-L200J22
CSM2F-6918-L050JT0
CSM2F-8518-L200J32
CSM2F-7036-L050J21
CSM2F-7036-L100J22
CSM2F-7036-L025J20
CSM2F-7036-L025J22
CSM2F-8518-L050JT1
CSM2F-8518-L100JT1
CSM2F-8518-L100J00
CSM2F-6918-L100JT0
CSM2F-6918-L050JT2
CSM2F-7036-L025J32
CSM2F-7036-L100J30
CSM2F-7036-L025J21
CSM2F-7036-L050J20
CSM2F-8518-L050JT0
CSM2F-8518-L100JT0
CSM2F-8518-L050JT2
CSM2F-6918-L100JT2
CSM2F-7036-L050J30
CSM2F-7036-L025J31
CSM2F-7036-L050J22
CSM2F-7036-L050J31
CSM2F-8518-L100JT2
CSM2F-6918-L200JT0
CSM2F-6918-L200JT2
CSM2F-7036-L100J20
CSM2F-8518-L200JT0
CSM2F-8518-L200JT2
CSM2F-8536-L025J31
CSM2F-8536-L025J32
CSM2F-8536-L025J20
CSM2F-8536-L025J21
CSM2F-8536-L025J22
CSM2F-7036-L100J32
CSM2F-8536-L050J22
CSM2F-7036-L050J32
CSM2F-7036-L050JT1
CSM2F-8536-L050J30
CSM2F-8536-L100J20
CSM2F-8536-L100J22
CSM2F-8536-L050J32
CSM2F-8536-L050J31
CSM2F-8536-L100J30
CSM2F-8536-L100J32
CSM2F-7036-L025JT2
CSM2F-7036-L025JT0
CSM2F-8536-L025JT1
CSM2F-8536-L025JT0
CSM2F-8536-L025JT2
CSM2F-8536-L050JT1
CSM2F-7036-L050JT0
CSM2F-7036-L050JT2
CSM2F-8536-L050JT0
CSM2F-8536-L050JT2
CSM2F-7036-L100JT0
CSM2F-7036-L100JT2
CSM2F-8536-L100JT0
CSM2F-8536-L100JT2