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MSP430F6736A: energy meter evaluation module (EVM) - Possible to connect maximum load (in Amps)

Part Number: MSP430F6736A

Sir, we are working as E-meter project. MSP430F6736A, this TI ic is suited for my application. 

your datasheet is mentioned, When CT or shunts are used, make sure the voltages across CUR2+ and CUR2- does not exceed 920 mV

my doubt is,

1.if possible to connect EVM device for my Machine (5A) for testing purpose and also know the maximum Amps (load) rating?

2.If possible to interface my own Current sensor(100 Amps) in EVM? possible means, how to interface?

Please send soon...

 

  • Hi Sivanathi!

    Thanks for your detailed post.

    Sivanathi said:
    Sir, we are working as E-meter project. MSP430F6736A, this TI ic is suited for my application. 

    That's great to hear. It's an excellent device for these types of projects.

    Sivanathi said:
    your datasheet is mentioned, When CT or shunts are used, make sure the voltages across CUR2+ and CUR2- does not exceed 920 mV

    You're exactly right. Basically, this maximum +/-920mV differential input voltage ensures that your input signal doesn't exceed the maximum full-scale range (FSR). Otherwise, the specified ADC performance may not be achievable, and if it's too high, the device could be damaged.

    Since you're using a CT, going from a maximum current of 30A to 120A will result in 4 times the voltage generated across the burden resistor. Thus, you'll need to make sure this maximum voltage across the burden resistor doesn't exceed the Full-scale Range (FSR) for the SD ADC channels. You'll want to use the lowest gain possible (ideally GAIN = 1) and size the burden resistor accordingly.

    Sivanathi said:
    1.if possible to connect EVM device for my Machine (5A) for testing purpose and also know the maximum Amps (load) rating?

    Yes, this EVM supports up to 100A RMS current, so 5A would be supported for your testing.

    Sivanathi said:
    2.If possible to interface my own Current sensor(100 Amps) in EVM? possible means, how to interface?



    Absolutely. If you know the burden resistor, turns ratio of the CT, and maximum expected RMS current, you can enter these in the CT sensor parameters inside the Energy Measurement Design Center (EMDC) GUI, and it will automatically calculate the peak sensor output voltage that's compared to the max input peak voltage (FSR) for the MSP430F6736A. For your CT, you probably know the turns ratio and max RMS current. Thus, you could use this feature in EMDC to enter various burden resistor values to figure out what value you should use in your design!

    If you haven't heard about EMDC before, please check out our recent introduction blog called Accelerate your metering design with the new Energy Measurement Design Center and software library for MSP430™ MCUs.

    Regards,

    James

  • Due to the upcoming US holidays, I'll be out of office from now until January 2nd. Unfortunately, responses will be delayed, so we appreciate your patience.

    Regards,

    James

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