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AMC3301: VOLTAGE SENSE

Maheswari V
Prodigy 10 points

Part Number: AMC3301
Other Parts Discussed in Thread: AMC3330

Hi 

we are using the AMC3301 in our voltage sense application.

Our input voltage is 28V,and we have implemented a three resistor voltage divider the top and bottom resistor are 37.4KE and the middle resistor is 499E.

However during the simulation we are not getting the expected output.

Could you please help me in understand the issueAMC3301 IMAGE .png

  • 0
    TI__Expert 7150 points

    Hi Maheswari,

    What application is this for?

    The way the input circuit is connected, there is ~14 volts on the INN/INP pins relative to the device ground (HGND).  HGND should be connected to INN, and your V1 supply ground and resistor chain should be relative to a separate ground node.

    Also, the AMC3301 is intended for current sensing applications.  You should use the AMC3330 instead, it has a higher input range and a higher input impedance.

    Thanks.

  • 0 in reply to Saleh Ahmad
    Prodigy 10 points

    Hi Saleh Ahmad

    Thank you for the clarification.

    We are using this circuit to verify whether the 28 V DC from the battery is present and stable.
    Our intention was to use this IC for voltage-sensing purposes by scaling the 28 V input down to below 250 mV through the resistor divider.

    While simulating, I used a simple two-resistor divider with 77.123 kΩ and 499 Ω, and I was able to get the correct output. However, when I use the three-resistor divider configuration, I am facing this issue

  • 0 in reply to Maheswari V
    TI__Expert 7150 points

    Hi Maheswari,

    Yes, when moving to the 3-resistor divider, the device HGND shouldn't be shared with the V1 source ground.  HGND should instead be connected to the low side of the sense resistor as below:

    Thanks.