Is the TSC1021 capable of measuring negative voltage?D

[avishai]

Posted on July 10, 2013 at 23:19

Hi

I read the datasheet of the TSC1021, but it is not clear if the IC is protected from negative voltage in the Vp/Vn terminals, or cant it measure the current.

I need to measure current of negative voltage, and planning on connecting Vn to the input, and Vp to the DUT.

Will it work?

  Thanks,

 Avishai

[Anthony BOIMOND]

Posted on July 15, 2013 at 16:23

Hello,

In fact Vp and Vm pins should be connected to either sides of the shunt resistor. Vp pin on the side where the electric potential is higher (where the current in entering in the shunt). You can see a description on schematic page 2 of the datasheet. 

The TSC1021 is capable of measuring current with common-mode comprised between 2.8V and 30V. The ''common-mode'' is intended as the Vm pin voltage measured with respect to the Gnd pin voltage.

The TSC1021 is also protected against negative voltages, this means that both Vp and Vm pins can be pulled as low as 32V below Gnd pin potential without any damage on the circuit. In these conditions, the TSC1021 is not able to measure current (its output won't give accurate image of shunt current).

Hope this can answer your questions, don't hesitate to contact us again in case of need.

Best regards,

Anthony

[avishai]

Posted on July 18, 2013 at 15:59

Hi

Do you have a solution for a component that can measure current on the negative voltages?

Thanks

 Avishai

[Anthony BOIMOND]

Posted on July 19, 2013 at 18:10

Hello Avishai,

For negative common-mode voltage, you can use another current sense amplifier named TSC103.

You can find datasheet

http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/CD00258729.pdf

.

This device needs to be supplied in ''dual-supply'' configuration to include negative common-mode inside its operating range. See chart at the end of this mail for explanation.

Hope this can help,

Best regards.

Anthony