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TS5A3166: Low-side Switch for Load Cells

Part Number: TS5A3166

Hello Team,

Good day. Our customer intends to use the TS5A3166 as a low-side switch for 4 load cells. They intend to add the switch into the ground to switch all 4 load cells at once, then read the signals separately through an ADC.

This low-side switching will be part of the initial power sequence when coming out of standby. Running the offset calibrations after coming out of standby and then read each of the cells individually.

Load cell output is 352Ω. Input is 402Ω. Would there be any possible issues with this configuration where all the 4 load cells are simultaneously switched together?

Thanks in advance!


Kind Regards,

Jejomar


  • Hi Jejomar

    To be sure I am understanding your configuration correctly, could you please provide a block diagram showing the setup of the application circuit?

    Also what is the maximum current output you expect to see through the switch?

    Best Regards,

    Parker Dodson

  • Hello Parker,

    The TS5A3166 powers on the load cells by switching them to ground as seen on the diagram below.



    With the 4 load cells at ~400 ohms, and 3.3V excitation, total current is ~33mA. If you need further information, please let me know. Thanks!


    Kind Regards,

    Jejomar 

  • Hi Jejomar,

    Thank you for the extra information! 

    The only problem I could see with this configuration is the switching speed at the control inputs. With the TS5A3166 at a 3.3V supply, the maximum turn on time is 11ns and the maximum turn off time is 13ns. To see proper operation the switching speed needs to be < 41.67 MHz, and it should also be lower than that because of the asymmetric nature of the turn on and turn off times. If the switching speed of the switch isn't that high there shouldn't be a problem.

    Best,

    Parker