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MSP430FR2355: MSP430FR2355 measuring current sense of DRV8801

Part Number: MSP430FR2355
Other Parts Discussed in Thread: DRV8801,

Hello,

I am designing a custom driver circuit, that employs the MSP430FR2355 and the DRV8801.

In order to measure the current sense pin of the DRV8801, which pin should I use on MSP430FR2355  so I can take advantage of the SAC?

What would be the best practices for employing such circuit? It seems TIA is out of the question, since it is a current to voltage converter, but maybe a PGA would suit?

I am looking at slau680, page 15, figure 10, that shows the pinout for the development board. Is there a better explanation to which pins can be used for SAC, PGA specifically.

Best Regards,

Can

Note: Image upload function is gone.

  • Hello can,

    That diagram will only show you which pins on the MSP430FR2355 connect to the corresponding LaunchPad header pins.  To know more about which pins to use for your purpose you will need to first look at the datasheet.  Specifically, section 4.3.  Next, look at the device's family user guide , chapter 20 for details on the SAC peripheral and how to use it.

    To answer your question, you will want to configure the PGA as a non-inverting amplifier and connect the motor current sense resistor to the (OA+) input and the (OA-) tied to ground.  See figure 20-5.

  • Hello Dennis,

    Thank you for your answer. I printed out the relevant sections of user guide, and studying it.

    I want to measure output of this amplifier with an adc. I wonder if there are any examples which illustrate using the SAC in non-inverting amplifier mode, and then measuring it with adc. If not, are there any special considerations for such setup, can I connect output of the amplifier to an adc pin?

    Best Regards,

    C.

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