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SN65HVDA100-Q1: Operating Voltage Range Question.

Part Number: SN65HVDA100-Q1

Hi

Customer is using SN65HVDA100-Q1 as LIN Transceiver for the Seat ECU project.

The customer is asking the question because there is a difference between the Datasheet specification when measuring the range of operating voltage with the sample.

* Test results (Voltage level is Pin 7 VSUP measurement)

- Normal operating interval : 7.9V or higher

- LIN Error: 6.9V ~ 7.9V

- LIN shut off : 6.9 volts or less

The data sheet specifications are as follows.

* Extended Operation With Supply From 5V to 27V DC (LIN Specification 7 V to 18 V)

Q : The Nominal supply voltage is a minimum of 7 volts or more. However, LIN errors are occurring up to 7.9V.

      Is that normal?

  • Hi Cho,

    I'm sorry to hear about the observed discrepancy. The LIN transceiver should continue to operate as specified and not enter the Underpowered System Mode unless Vsup drops below the UVsup threshold. Could you please provide more information to help find the cause of the mismatch?

    1. Could you define the behavior of the transceiver when the "LIN Error" and "LIN Shutoff" occur? What are the states of the TX, RX, and LIN pins during these states? It may be helpful to see all of these lines and Vsup on a scope during the ramp down. 

    2. You describe that a "LIN Error" occurs once Vsup drops below 7.9V. Is this a specific error reported by the controller or system? Is this a communication failure or some other type of exception? As stated above, knowing the state of SN65HVD100-Q1's input and output pins will help identify the current state of the device under these conditions. 

    3. Are there other components in the system that rely on the Vsup rail for power? For instance: is there an LDO that uses Vsup to supply power to the controller or other components in the system? If so, please check that such components are also expected to operate normally at the lower Vsup levels. 

    Please let me know if there are other aspects of the system you believe may be affecting this observation. 

    Regards,
    Eric

  • Hi Eric,

    Thank you for your reply.

    I will update your request after checking it with the customer.