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DRV3201-Q1 Startup time of Boost converter

Toshio Ushikubo
Mastermind 9620 points
Other Parts Discussed in Thread: DRV3201-Q1

Hello,

Customer wants to know startup time of boost converter from B_EN changes to High.

I have already answer answered as follows.

“The time until the boost reaches it's final value is strongly depending on the input voltage, the coil, the boost capacitance, the load, the resistor on GNDLS_B and probably some other parameters. Best would be to read out the boost under voltage flag of STAT1 resistor and wait until it goes low.”

 

Please answer following additional questions related above requirement.

 

Q1: startup time of typical application

Please advise minimum and maximum startup time in case of “Figure 16. DRV3201-Q1 Typical Application Diagram” of datasheet (L=22uH, C=1uF, GNDLS_B resistor=330m ohm).

Customer wants to know how the startup time varies.

 

Q2: V BOOSTUV threshold

Please advise if V BOOSTUV threshold (11V min, 11.9V max) is same in both case of BOOST voltage is increasing and decreasing, or different.

Does it have Hysteresis?

 

Q3:

In case of V BOOSTUV doesn’t have Hysteresis, are there any risk that boost under voltage flag is unstable near the threshold voltgage?

 

Best Regards.

  • 0
    TI__Guru** 114905 points

    Hi Ushikubo-san,

    We will contact our expert on this device. He will respond soon.

  • 0
    TI__Expert 3555 points

    Ushikubo-san,

    Q1:

    As you stated the startup time will depend on the conditions of the boost. The regulator itself will start switching as soon as B_EN is asserted, and has a typical startup time of around 200-300us to the final value based on bench observation. This is with the recommended components from the datasheet that you pointed out, and there is only a slight variation when varying the VS voltage. Continuously reading the BOOSTUV flag in STAT1 will give you a good idea of when the regulator is up, but this flag will release a little bit before the regulator reaches the max value.

    Are there any specific conditions that you need to know for min/max startup times for?

    Q2/3:

    The BOOSTUV threshold does have hysteresis, so you should not see any instability near the threshold voltage because of this.

    Regards,

    Will Toth

  • 0 in reply to William Toth
    Mastermind 9620 points

    Hello William-san,

    Thank you for your answer.

     

    Q1:

    Are there any specific conditions that you need to know for min/max startup times for?

     

    I want to know the min/max startup times for DRV3201-Q1 Typical Application Diagram” of datasheet (L=22uH, C=1uF, GNDLS_B resistor=330m ohm).

     

    Best Regards.

  • 0 in reply to Toshio Ushikubo
    Mastermind 9620 points

    Hello William-san,

     

    Additionally, could you please advise hysteresis voltage seize of BOOSTUV?

     

    Best Regards.

  • 0 in reply to Toshio Ushikubo
    Mastermind 9620 points

    Hello William-san,

    Please answer following questions I posted on Oct 22 2014 and Oct 28 2014.

    (Black is your answer and Blue is my additional question.)

     

    Q1:

    Are there any specific conditions that you need to know for min/max startup times for?

     

    I want to know the min/max startup times for DRV3201-Q1 Typical Application Diagram” of datasheet (L=22uH, C=1uF, GNDLS_B resistor=330m ohm).

     

    Q2/3:

    The BOOSTUV threshold does have hysteresis, so you should not see any instability near the threshold voltage because of this.

     

    Could you please advise hysteresis voltage seize of BOOSTUV?

     

    Best Regards.

  • 0 in reply to Toshio Ushikubo
    TI__Expert 3555 points

    Ushikubo-san,

    Let us take this offline and work with the FAE in your area. I will brief them on the specifics.

    Regards,

    Will Toth