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DRV5013-Q1: tON=Low Duration after Power-up

Part Number: DRV5013-Q1
Other Parts Discussed in Thread: DRV5013

Dear, Sir.

tON typical & maximum values are defined on the datasheet, page 6.

My customer is asking the duratuion of ON=Low after power-up.

Is it possible to clarify & assure about such duration?

Please give your advice.

Best Regards,

H. Sakai

  • Sakai-San,

    This event is typical part of the power on sequence and is part of device initialization.  I was able to measure this on a single unit.  On this particular unit, it appears to happen at the same delay of about 22 us and for the same duration of about 8 us.  This may vary from device to device, however.


    While the delay to the output being restored on this unit is about 30 us, we do not guarantee the data to be valid until after the specified tON time.  In the datasheet this is typically 35 us, but max value can vary based on device variant to as much as 50 us or 70 us.

  • Dear, Scott-san. 

    I am feeling a mount of gratitude for your valuable information. 

    Sorry again, I would like to double-confirm. 

    The customer's target device is DRV5013AD-Q1. 

    1. The customer require the assurance for tON=Low duration. 

        Is it possible? 

    2. If above was No, Is it possible to measure some samples? 

    3. If above was No, tON typ.= 35us, tON max. = 50us. It is max = typ x 1.43 under all temp range. 

       To reflected this variation, tON Low typ. = 8us, max. = 12us. 

       It is not the assurance, it is just the reference. 

       How do you think about this? 

    Best Regards, 

    H. Sakai

  • Sakai-San,

    The data captured above was using the DRV5013AG -Q1 which we had samples available for use on the bench.  The 8 us value I referred to was the measured tON=Low Duration for that one unit.  

    For this device it was quite repeatable at room temp and 5V supply.  However, given variations due to process, voltage, or temperature we may see changes in the duration of the event from unit to unit, and we may see differences when the low output event occurs.

    I don't think it is safe to assume a scalar multiple of the typical values to determine the relationship with the max spec. The typical and max values in the datasheet are based on data seen across several units and the specified operating conditions.  The datasheet does not guarantee any value for this low duration, but we do guarantee the total tON time. 

    Under normal circumstances it is usually safe to start logging data at the typical value for tON, but there is still risk that the initial data may not yet be valid if captured before the tON Max specification at corner conditions.  We recommend using the the tON Max time for the safest mode of operation prior to logging any output data.

  • Dear, Scott-san. 

    Thank you so much for your valuable advice. Sorry please teach me about additional. 

    tON time looks to composite with 1st High duration, Low duration, 2nd High duration. 

    1. According your explanation, 1st High duration will be delay till the device initialization. 

        Low duration will be for the initialization. 

        For what is 2nd High duration? 

    2. I wonder 2nd High duration can be seen on all device variation? 

    Best Regards, 

    H. Sakai

  • Sakai-San,

    In my plot above the magnet was placed such that the output would end high, so we don't see the second high duration.  This is also part of the device initialization process and is normal.  This second pulse is also part of the total tON time.  Depending on magnet polarity, we must wait until the full initialization process is complete before data is valid.  Please recommend use of the outputs only after the tON time has passed.

    Thank you,


  • Dear, Scott-san. 

    Thank you so much for your valuable advice. 

    I wonder 1st High duration, Low duration, 2nd High duration can be seen 

    even if the magnetic field strength BRP < B < BOP, or other strange field 


    Sorry again, but I would like to double-confirm. 

    Best Regards, 

    H. Sakai

  • Sakai-san,

    This is not a measurement that can be easily performed on my bench since it requires a very accurate magnetic field to reproduce.  However, we have shown this case in the datasheet in figures 15 and 16. Here, the device will cycle through both parts of the initialization sequence followed by Hi-Z on the output.  Once the magnetic field triggers at either BRP or BOP then the output will be driven. The behavior of a low output followed by a high output during the power on sequence is normal in all cases and should be expected.  tON is not satisfied until this full initialization is complete.  It is safest to design around the tON Max duration to prevent any false data acquisition.  

  • Dear, Scott-san. 

    Thank you so much for your valuable information. 

    Currently, the customer is checking the power supply voltage using a components. 

    They are think to utilize the Low duration as the indication of power supply is OK. 

    It is to reduce the system cost. 

    Is it possible to clarify the design spec of Low duration & the condition? 

    Of course,  you don't need to assure that. 

    Best Regards, 

    H. Sakai

  • Sakai-san,

    I understand your questions better now.  Thank you for the insight. 

    The low duration is a repeatable part of startup regardless of magnetic field. I suppose it might be possible to track system supply turning on based on this.  However, I do not have data that I can share that would describe how repeatable the timing is for a large number of units, voltage levels, or temperatures. There would be some risk in relying on this for a power good signal. 

    If somebody were to try using this portion of the startup for this purpose, they would need to determine what voltage constitutes a minimum power good condition for the entire system and then make sure that they can repeatably observe the low duration at that voltage.  It would also be important to determine the tON for the rest of the system and plan startup time accordingly.  It is possible that after only 70 usec that there are still other devices initializing.   As far as data from the DRV5013 is concerned, I would definitely recommend not using any output data until after the maximum tON, especially when operating in corner conditions.   

  • Dear, Scott-san. 

    I am feeling a mount of gratitude for all of your valuable & kindly advice. 

    I would like to double-conform about your standing point. 

    1. Do you mean that the customer must verify as well and assure by themselves if they would utilize 

        the low duration for the power good or power supply line open detection on their system? 

    2. I understand you can not assure the low duration. 

       Is it possible to check the low duration on some samples as the reference actual data if the 

       customer requested? 

    Best Regards, 

    H. Sakai

  • Sakai-san,

    Scott is out of the office for the next few weeks, so I will be taking over this thread on his behalf. Please find answers to your question below.

    1. Yes. We only chartacterize the total time required to turn the part on. If the customer is wanting to do something based on the low portion only of the t_on signal, they will need to characterize this themselves, and we can not guarantee proper operation of the device until the full t_on has elapsed for the device.

    2. How many samples are you needing examined here? Again, even if I gather this data, the customer needs to be aware that this is not a datasheet characterization, and we are not advocating that the part be used in this way.