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DRV8210: PH/EN mode not working if MODE pin is pulled-up on power up

Piotr Daniel
Prodigy 10 points
Part Number: DRV8210
Other Parts Discussed in Thread: DRV8838,

Hi!
I have a weird problem with DRV mode selection:
When device is powered up it can operate only in half-bridge and PWM modes and I can't turn on PH/EN mode in any way other than holding mode pin in high impedance on power up and then pulling it up (which in my design requires manual work, which is simply put stupid).
Holding it LOW and then HIGH doesn't work either. Of course I've tried holding it HIGH on power up - that doesn't worked either. I've spent several days on it without any results :/ 
I've just wanted to replace DRV8838 with DRV8210 and encounter such a weird problem (design works perfectly fine with DRV8838) 
Any help will be appreciated!
Regards,
Piotr

  • 0
    TI__Guru 54675 points

    Piotr,

    That is very strange indeed.  The circuit diagram below should work. 

    Can you send me a photo of the top of the device and let me the part number you ordered and from where?

    Regards,

    Ryan

  • 0 in reply to Ryan Kehr
    Prodigy 10 points

    Hi Ryan,

    My schematic is exactly the same and DRV behaves as it's dead (despite correct driving signals presence). After desoldering, pullup jumper device enters half-bridge mode as expected (I've looked at output waveforms using a scope). The same happens after pulling down pin 7 - it enters PWM mode as expected.

    I'm using DRVs provided as samples by the Polish TI sales division, shipped directly from the TI warehouse (in the Netherlands I believe), so I reckon they are not counterfeits ;) 

    just to give you some more details my VM is 5V, VCC is 3.3V and PWM logic levels are 0-3.3V (generated from STM32 microcontroller)

  • 0 in reply to Piotr Daniel
    TI__Guru 54675 points

    Piotr,

    I am not suggesting they are counterfeit, but believe it or not...even we make mistakes on shipping parts. :)  If you can just snap a quick picture, I can verify.  

    Have you tried more than one unit?

    Regards,

    Ryan

  • 0 in reply to Ryan Kehr
    Prodigy 10 points

    Ryan,

    I've tried several ones - all from the same tape 

    attached photo below

    It looks right I guess?

    Regards,

    Piotr

  • 0 in reply to Piotr Daniel
    TI__Guru 54675 points

    Piotr,

    Looks 100% correct to me.  Thank you for sharing.  

    We will do some investigation on our side.  In the meantime, can you please share your scope results of the EN/PH and the 2 outputs with MODE = HIGH (VCC)?  

    Regards,

    Ryan

  • 0 in reply to Ryan Kehr
    Prodigy 10 points

    Ryan,

    I can share them tomorrow, but I guess they won't be helpful because the outputs are just constantly low, no matter the driving signals

    Regards,

    Piotr

  • 0 in reply to Piotr Daniel
    TI__Guru 54675 points

    Piotr,

    OK, that is even more interesting.  Pedro will be supporting this thread for the next couple of days and is searching for an EVM now to try and reproduce.  

    Regards,

    Ryan

  • 0 in reply to Piotr Daniel
    TI__Expert 4955 points

    Hello Piotr,

    Allow me to investigate this in lab with one of our boards, I will share back my results by EOD on Monday.


    Best,


    Pedro Arango Ramirez

  • 0 in reply to Pedro Arango Ramirez
    TI__Expert 4955 points

    Hello Piotr, 

    I have troubleshooted the DRV8210 in one of our boards and was not able to recreate the situation you described. We are going to need some more information to better understand the setup of your system and the wakeup conditions. One of my colleagues will reach out with the information required. 

    Best,

    Pedro Arango Ramirez

  • 0 in reply to Pedro Arango Ramirez
    TI__Genius 14485 points

    Hi Piotr,

    The difference between the DRV8210 in PH/EN mode and the DRV8838 is that the DRV8210 has an autosleep mode. In the DRV8838 when nSLEEP = HIGH and IN1 = IN2 = LOW, the device will be in brake mode when VCC ramps above VUVLO. In the DRV8210, when when IN1 = IN2 = LOW, and the supply ramps above UVLO, the OUTx pins will be in the Hi-Z state until the EN pin toggles high. Additionally, the EN pin must be high for longer than tWAKE for the device to fully wake up.

    If you are providing a PWM signal to the EN pin, please ensure that it stays high for longer than tWAKE before asserting the duty cycle.

    If you still have issues after checking those things, please send any scope shots showing the incorrect operation of the DRV8210. Showing the EN, MODE, and OUT signals should be the main ones to help us debug.