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DS90LV047A: Any damages can happen when DOUT+/- are shorted to GND or connected to each other?

Part Number: DS90LV047A

Tool/software:

Hi team

Could you please tell whether any damages can happen at conditions below?

1. DOUT+ or/and DOUT- are shorted to GND.

2. DOUT+ is connected to DOUT-.

Regards,

Noriyuki Takahashi

  • The absolute maximum ratings allow this. The electrical characteristics specify IOS and IOSD as < 9 mA.

  • Hello, 

    I am looking into this and will get back to you next week.

    Thanks, Amy

  • Hello,

    Please refer to the "Output short-circuit current" and "Differential output short-circuit current" sections. As far as absolute maximum conditions are concerned, the device can handle this but it is not recommended to operate for extended periods of time.

    Thanks, Amy

  • Amy,

    Thanks.

    Please refer to the "Output short-circuit current" and "Differential output short-circuit current" sections.

    Does the charcteristics mean that the device has the current limit function for the short circuit? 

    the device can handle this but it is not recommended to operate for extended periods of time.

    Could you tell the reason why it is not recommneded to operate for extended periods of time?

    Regards,

    Noriyuki Takahashi

  • 1. LVDS drivers have a current limit of about 3.5 mA during normal operation. The limit mentioned above is a worst-case value.

    2. In general, the power dissipation at the absolute maximum rating limits might increase the die temperature too much. But for this device, 4 × 9 mA × 3.3 V = 119 mW, so the worst-case temperature increase is RθJA × P = 13.5 °C above ambient, which is harmless even for extended periods of time.

  • Hi Noriyuki,

    Figure 3 is another good resource to understand this. Abs/max values are not intended to be operated under those conditions for a long period of time, whereas the recommended operating conditions are the recommended conditions to operate under. 

    Please let me know if you any follow up questions on this.

    Thank you, Amy

  • Amy,

    Sorry, I am still confused.

    Abs/max values are not intended to be operated under those conditions for a long period of time,

    I can understand this in general, but what do you think about Clemens's comment as below?

    2. In general, the power dissipation at the absolute maximum rating limits might increase the die temperature too much. But for this device, 4 × 9 mA × 3.3 V = 119 mW, so the worst-case temperature increase is RθJA × P = 13.5 °C above ambient, which is harmless even for extended periods of time.

    Regards,

    Noriyuki Takahashi

  • Hi Noriyuki,

    For consistency, if a value is listed as an Abs/ max in the datasheet, then this is Texas Instruments official statement regarding the recommended device usage. Abs/max values are not intended to be operated under those conditions for a long period of time, whereas the recommended operating conditions are the recommended conditions to operate under. Operating under the conditions that Clemens mentions is at the customer's own risk.

    Regards, Amy 

  • Amy,

    I see, but sorry, I am still confused. 

    Looking at the electrical characteristics, IOS and IOSD can be -4.2mA typ, -9mA max.  Then, looking at the abs max, short circuit duration is specified as continuous. Could yout tell what "continuous" mean? Does "continuous" mean below?

    Abs/max values are not intended to be operated under those conditions for a long period of time

    Regards,

    Noriyuki Takahashi

  • "Continuous" means that you are allowed to use this for a extended periods.

    That warning applies to limits that have a numeric value. For example, the power dissipation in the PW package must not exceed 866 mW (or, with derating, 452 mW at 85 °C). A power dissipation of 867 mW can damage the device immediately. A power dissipation of 866 mW will not damage the device immediately, but can degrade it if used for extended periods. (As shown above, shorted outputs dissipate 119 mW, so they are safe.)

  • Hi Noriyuki,

    Continuous operation in this case would mean running the device in a continuous short circuit condition.

    This is not recommended to operate in this condition for extended periods of time. 

    Thanks, Amy