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DRV8303: Dead time setting DRV8303 vs DRV8301

Olrik Maier
Expert 5010 points
Part Number: DRV8303
Other Parts Discussed in Thread: DRV8301,

Hi

my customer is unsing DRV8301 and DRV8303.

When looking into the dead time configuration by the external resistor in the DS for DRV8303 it should not be added to the dead time set extrnaly by the MCU while at DRV8301 it should be added.

Based on some testings the DRV8303 shows exact the same dead time behaviour like the DRV8301 - it seems that the value set by the register is added to the external set MCU dead time like DRV8301.

Parts are used in 6 PWM mode.

Do you have a more detailed describtion of the dead time of DRV8303 and if it should be added or not ?

See DS extracts below.

 

 

 

 

Best wishes,

Olrik

  • 0
    TI__Intellectual 1345 points
    Hi Olrik, I checked the two devices and the dead time behavior should be identical. The correct behavior is the one in the DRV8301 d/s
    "Dead time programming definition: Adjustable delay from GH_X falling edge to GL_X rising edge, and GL_X falling edge to GH_X rising
    edge. In 6-PWM input mode, this adjustable value is added to the timing delay between inputs as set by the microcontroller externally"

    the DRV8303 d/s will need to be updated . We apologize for the errata and inconvenience in the document.
  • 0 in reply to Anuj Narain
    TI__Expert 5010 points

    Hi Anuj,

    do you have a more detailed describtion of the dead time control of DRV830x.

    HOw does the 6 PWM Mode exact work, how is the delay set by the microcontroller and where is the dely time set by the register add to.

    Many Thanks

    Best wishes,

    Olrik

  • 0 in reply to Olrik Maier
    TI__Expert 5010 points

    Hi Anuj,

    do you have a more detailed describtion of the dead time control of DRV830x.

    HOw does the 6 PWM Mode exact work, how is the delay set by the microcontroller and where is the dely time set by the register add to.

    Many Thanks

    Best wishes,

    Olrik

  • 0 in reply to Olrik Maier
    TI__Intellectual 1345 points
    Hi Olrik - I am working with the original designer to create this.
  • 0 in reply to Olrik Maier
    TI__Intellectual 1345 points
    Hello Olrik,
    Below is a more detailed description of DTC behavior . We will plan to include this in the datasheet in the future.
    - When a INH_x or INL_x transition of L->H is applied to any of the PWM pins , DRV8301 will internally delay the signal for the DTC dead time and then apply it to the output
    - This is not done for H->L transitions
    - So, for example if INH_A (L->H) and INL_A (H->L) are applied at exactly the same time at the input , INH_A will be delayed by DTC time while INL_A will be applied immediately. So, no shootthrough.
    - If the microcontroller already has a dead time in the above example (INH_A comes 100ns late from MCU) , then INH_A will be delayed by a total of (100ns + DTC)

    There are also other safeguards
    - Truth table will block intentional INH_x, INL_x L->H at the same time
    - Internal handshake will verify that the output is low before turning on the other driver in the same phase
  • 0 in reply to Anuj Narain
    TI__Intellectual 1345 points
    Hi Olrik - please let me know if this answers the question.