AMC1301: resistor heating

Hi,

Are the series resistors, commonly paired with a differential capacitor for an anti-aliasing filter, to the input of the AMC1301 heating up, or is the shunt resistor in series with the 300A load heating up? 

Can a more complete schematic be provided? 

Reducing the shunt resistor resistance or increasing the power dissipation rating is typically the solution. We have this excel calculator and these application notes for assistance with selecting a device and shunt resistor:

https://www.ti.com/lit/an/sbaa460/sbaa460.pdf?ts=1684179841117

https://www.ti.com/lit/an/sbaa568/sbaa568.pdf

https://www.ti.com/lit/an/slyt810/slyt810.pdf

https://www.ti.com/lit/zip/sbar020

I would recommend either the AMC1300B or AMC1302 as replacement for the AMC1301. AMC1302 has a smaller input voltage range which is helpful for high current applications. We also have the AMC3301 and AMC3302 with integrated DC/DC converters to simplify the design. 

Hi,

This schematic does not have the specifications of the input resistors included. Have you tried increasing the resistance or power dissipation rating of the input resistors? 

Is the 300A value DC or A_rms? 

I see that you have 4x500uohm shunt resistors measuring the current. From the schematic and resistor selection point of view, this should be OK, however how is the heat being dissipated?

What oz copper and is there a large plane available to dissipate the heat? 

Are you using a heat sink or fans? 

Please see the documents I posted in my previous response for additional information.