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DRV8873-Q1: Internal Protection Diode at DVDD Pin

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Replies: 5

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Part Number: DRV8873-Q1

Hello,

Does the DVDD pin of DRV8873S-Q1 have an internal protection diode with other pins? If the DVDD pin has a diode internally to the VM pin, for example, a current could flow into the VM from the DVDD when the DVDD voltage is higher than the VM. If the DVDD has an internal diode with other pins, a current could flow into the device when the DVDD voltage is higher than that pin.

One more question, Figure 9 in the data sheet shows that some circuits are tied to nSLEEP internally. Is it a typo? If not, I guess the circuits draw an operating current from nSLEEP pin. Is it correct?

Best regards,
Shinichi Yokota

  • Hi Yokota-san,

    Does the DVDD pin of DRV8873S-Q1 have an internal protection diode with other pins? If the DVDD pin has a diode internally to the VM pin, for example, a current could flow into the VM from the DVDD when the DVDD voltage is higher than the VM. If the DVDD has an internal diode with other pins, a current could flow into the device when the DVDD voltage is higher than that pin.


    The DVDD pin has an internal protection to prevent current flowing from DVDD to VM. Please note that DVDD should not be higher than VM unless the device is powering down.

    Also internal diode paths were considered, and undesired current flow was prevented.

    One more question, Figure 9 in the data sheet shows that some circuits are tied to nSLEEP internally. Is it a typo? If not, I guess the circuits draw an operating current from nSLEEP pin. Is it correct?


    This is not a typo; these circuits are connected to nSLEEP. This is also specified in the Description section of the Pin Functions (nSCS) and the Electrical Characteristics (SDO)

    Best Regards,
    Rick Duncan
    Motor Applications Team

  • In reply to Rick Duncan:

    Rick-san,

    Please let me ask three more questions.

    1. When SDO is shared by other slave devices, could a current flow through a body diode of the DRV8873S-Q1's SDO output buffer if the SDO is driven High by another slave device and nSLEEP is driven Low?
    2. Is it correct to understand that the SDO pin is tolerant of up to 5.7 V regardless of the other pin voltages according to the absolute Max ratings?
    3. What are the Min values of internal pulldown resistor of the nSLEEP pin, internal pullup resistors of DISABLE and nSCS pins?

    Best regards,
    Shinichi Yokota

  • In reply to Shinichi Yokota:

    Hi Yokota-san,

    1. When SDO is shared by other slave devices, could a current flow through a body diode of the DRV8873S-Q1's SDO output buffer if the SDO is driven High by another slave device and nSLEEP is driven Low?


    Yes, current could flow through the body diode if SDO is driven by another slave and nSLEEP is driven low.

    1. Is it correct to understand that the SDO pin is tolerant of up to 5.7 V regardless of the other pin voltages according to the absolute Max ratings?


    Yes, SDO is tolerant of up to 5.7V.

    1. What are the Min values of internal pulldown resistor of the nSLEEP pin, internal pullup resistors of DISABLE and nSCS pins?


    Expect the minimum resistance of nSLEEP to be 80k, DISABLE to be 90k, and nSCS to be 350k.

    Best Regards,
    Rick Duncan
    Motor Applications Team

  • In reply to Rick Duncan:

    Rick-san,

    Sorry for one more question...

    • Does the nSLEEP pin of the DRV8873S-Q1 have an internal current path to internal supplies such as protection diodes or other parasitic elements?

    Best regards,
    Shinichi Yokota

  • In reply to Shinichi Yokota:

    Hi Yokota-san,

    nSLEEP does not have an internal current path to internal supplies.

    Best Regards,
    Rick Duncan
    Motor Applications Team

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