Kelvin connection in voltage regulator

[deba_fire]

Hi All,

I need some information on Kelvin connection which some regulator data sheets suggest to use.What exactly is kelvin connection?why is it important?And if not followed what are the consequences?

Please help.

Regards
Deba

 

[srizbf]

kelvin connection is 4 wire circuit.
there are 2-current carrying lines and
2-voltage sensing lines.

the current carrying lines (or terminals) are used for
connecting the load . this line is a heavy or thick line .

the voltage sensing pair lines or terminals are
usually connected to the load .

at first it looks all pairs are identical(since both are connected to the same load) . but the voltage sensing lines will carry
the voltage levels only and it should not be used for load current carrying.

the voltage sense line connectd to the regulators appropriate points , sense the (load) voltage and regulates.

the idea is ,the drops in the current carrying lines are taken into account
and the regulator will fix the voltage required at the 'load'

hope you got the point.

srizbf
31stmay2010

 

[otherguy]

They are used in current sensing circuits. The idea is that you don't want current flowing through these connections. You want to route them with the thinnest trace width that you are using on the board ie, high impedance trace. I usually route them coupled together as much as I can and and short as possible. If short isn't a possibility, keep other signals away as much as possible.

 

[karesz]

Hi,
Others called: Four-terminal sensing...
https://en.wikipedia.org/wiki/Four-terminal_sensing
Kelvin (4-wire) resistance measurement: https://www.allaboutcircuits.com/vol_1/chpt_8/9.html
K.

 

[dmd4raj]

There are two types of sensing method available

1.Force Current measure Voltage(FCMV)
2.Force Voltage Measure current

But widely FCMV is used in all kind of circuits

As you know thicker conductor carries more current due to low impedance than the thinner conductor

So Use wide trace width for the Force current traces and thin trace for the sense line

Kelvin connection is nothing but the point at which thicker and thinner traces shorting together

this should be shorted at point where we want to measure the the voltage

Refer the attachement for reference

Thanks
Rajan.k