TMCS1101: Is the pins 1 and 2 connected together? I wanted to use this to sense current in two lines (not in combination, current will be passed through any of the lines at a time) coming from a relay

Thank you so much. Yes, for SPDT, that will work. But I have a bunch of DPDT relays as well. Now I know - I will have to use two TMCS1101 for a DPDT relay. Do you know any other current sensing IC do what exactly I need in this case?

Hi Ramesh,

Agreed you’ll have to use two devices for every DPDT relay.

If you can use shunt based current sense amplifiers, we have multi-channel options such as INA2180 and INA4180. Though these are based on different technology and have very different specifications.

Regards, Guang

A related question - Is it okay to place the TMCS1101 on the other side of the PCB where the relay is mounted? (Exactly on the back side of the relay)? Will the magnetic field generated by the relay affect TMCS1101?

Hi Ramesh,

The Hall sensor in the TMCS1101 die is sensitive to any magnetic field present, including the intended field caused by current through the device leadframe, or ambient fields from the rest of the system. Therefore PCB placement, layout, and overall system and material design can have a big impact on performance.

The only way to quantify the impact is to measure it in the lab, or perform a detailed magnetic simulation.

Best regards,

Ian Williams
Applications Manager
Current Sensing