Kelvin connection of 2milliOhm sense resistor

[cupoftea]

Hi,
We are doing a 48W Buck 8v to 5v.
2milliOhm sense resistor in the LTC7803 circuit.
Which lends itself better to kelvin connection...a 2512 resistor, or a "wide" 1225 resistor?
We'd rather not buy a pricey 4 terminal resistor.

 

[mtwieg]

Not sure what you mean by "lends itself better to kelvin connection". You should use a kelvin connection for any package size. Wide packages for current sense resistors are generally beneficial because they have lower ESL (and maybe better power handling).

 

[crutschow]

Of course, for the Kelvin connection, the resistor pads should be large and have two traces, one to one side of the pad, for the Kelvin connection, and one to the other side of the pad for the current, to minimize the pad resistance affecting the Kelvin voltage reading.