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DRV8436E: about output current

Yuta Nishie
Genius 3020 points
Part Number: DRV8436E

Hi,

We got questions from our customers and would appreciate it if you could answer them.

The data sheet shows the min / max values for ΔItrip over the entire temperature range.


1. Is this "prone to max value in a high temperature environment" or "prone to max value in low temperature"?
2. Is it possible to provide normal distribution data for the measured output current values (300mA if possible) for multiple Lots?

Best Regards,

Nishie

  • +1
    TI__Expert 4955 points

    Hello Nishie-san 

    Thank you for the question, it took me a bit of time to find the characterization data to provide a detailed and accurate response.

    1. For the Itrip value, the device is prone to max value in lower temperature, while prone to min value in higher temperature. This was taken directly from the characterization data. And it holds true over a large range of temperatures, supply voltages, and % current settings. 
    2. Unfortunately this will not be possible as we do not do current values over multiple lots.

    Best,

    Pedro Arango Ramirez

  • 0 in reply to Pedro Arango Ramirez
    Genius 3020 points

    Hi Pedro Arango Ramirez-san,

    Thank you for your support.

    Let me ask you an additional question about No.2.

    Is there data for one lot instead of multiple lots?

    Best Regards,

    Nishie

  • 0 in reply to Yuta Nishie
    TI__Expert 4955 points

    Hello Nishie-san,

    It would be time intensive to compile the characterization data and I can't ascertain that it would be at 300mA, if completely and absolutely necessary I can start to compile it, but it will take me 48 hours. Before starting though I would like to ask you a couple of questions to make sure that if there is an alternate solution we can pursue it. 

    Might I ask what is the purpose of obtaining the data, and would it be useful data if it is not taken at the 300mA threshold? 

    Best,

    Pedro Arango Ramirez 

  • 0 in reply to Pedro Arango Ramirez
    Genius 3020 points

    Hi Pedro Arango Ramirez-san,

    Might I ask what is the purpose of obtaining the data, and would it be useful data if it is not taken at the 300mA threshold? 

    ->The purpose is as follows.
    Whether or not a motor driver can be used in a customer's product depends on the output current accuracy.
    Therefore, I want normal distribution data to see how accurate it is.
    As a background to the question, the output current accuracy (ΔItrip) of the DRV8436E is min = -13%, max = 10%, and the customer's required specifications are ± 10%.
    However, when the customer set the output current to 300mA and actually measured 3 samples, it was + 5% to 7%.
    Therefore, if the normal distribution data is within ± 10%, it may be adopted.

    If possible, 300mA is desirable.
    However, there is no problem even if it is not 300mA, as it is only necessary to know the tendency of the output current accuracy to be on the plus side (value close to max) or the minus side (value close to min).

    Best Regards,

    Nishie

  • 0 in reply to Yuta Nishie
    TI__Expert 4955 points

    Hello Nishie-san,

    Understood, I will attempt to compile the data and will get back to you within 48 hours. 

    Best,

    Pedro Arango Ramirez

  • 0 in reply to Pedro Arango Ramirez
    Genius 3020 points

    Hi Pedro Arango Ramirez-san,

    I'm sorry for your inconvenience but thank you for your cooperation.

    Best Regards,

    Nishie

  • +1 in reply to Yuta Nishie
    TI__Expert 4955 points

    Hi Nishie-san, 

    Not an inconvenience, at all. I am happy to help. Attached is the Char table information including Itrip. I have highlighted some of the boxes that are indicative of the typical behavior and are in line with my previous response. 

    Best,

    Pedro Arango Ramirez

     Char-Report-DRV8889Q-1p3-ATE-CHAR.xlsx

  • 0 in reply to Pedro Arango Ramirez
    Genius 3020 points

    Hi Pedro Arango Ramirez-san,

    Thank you for sending the materials.
    The title of this document is described as DRV8889Q, but Is it okay to send it to the customer as DRV8346E data?

    Best Regards,

    Nishie

  • +1 in reply to Yuta Nishie
    TI__Expert 4955 points

    Hello Nishie-san

    Yes, they were made off the same die so changing the name to DRV8346E would be best. 

    Best Regards,

    Pedro Arango Ramirez

  • 0 in reply to Pedro Arango Ramirez
    Genius 3020 points

    Hi Pedro Arango Ramirez-san,

    Thank you for your reply.

    I got an additional question from a customer.
    ・ What kind of motor did you use for the materials you received before?

    As a background, the customer set the output current to 300mA (Vref = 660mV) and measured ΔItrip (n = 3) using a motor with a coil resistance of 9.7Ohm and a coil inductance of 4.5mH.
    ΔI trip = 5% to 7%, which is larger than the value of the materials you received.

    Best Reagrds,

    Nishie

  • +1 in reply to Yuta Nishie
    TI__Expert 4955 points

    Hello Nishie-san, 

    I am unsure with which motor the data was procured as this was done by the validation team under an idealized situation. It is possible that this was performed via a tester. However, ΔI trip = 5% to 7% for Vref of 660mV lies within the datasheet specs. At this voltage level the part is working as expected, I would say even better than expected. according to the possible deviations in the datasheet.

    Best,

    Pedro Arango Ramirez.