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UCC27710: About Ton time.

Guru 10385 points
Part Number: UCC27710

Hi team.

I' like to know about the pulse ON time.

How long is the pulse ON time ?

According to the data sheet , it only write OFF time.

Sincerely.
Kengo.

  • Hello Kengo,

    Thank you for the interest in the UCC27710. I may need to get more details about your question regarding the pulse on time. I will assume you are referring to the minimum input pulse that will change the driver output. Both the minimum high pulse and the minimum low pulse are specified in the datasheet as tON and tOFF. The typical value for both is 40ns and the maximum for tON is 60ns and maximum for tOFF is 75ns. Any driver input pulse that is less than these values will be rejected by the driver and the LO or HO will not respond. See below.


    If you are referring to the dead time, DT, this does guarantee a minimum time that both LO and HO are off with not dead time on the LI and HI inputs. Otherwise, the HO and LO follows the LI and HI inputs after the propagation delay times of 140ns specified in the datasheet.

    Please confirm if this addresses your question, or you can post additional questions on this thread.

    Regards,


  • Hi Richard.

    Thank you for your quick response.

    I'd like to know the Ton time.

    So,the data sheet only shows the minimum time.

    I think there is no maximum value for this driver..

    Sincerely.

    Kengo.

  • Hello Kengo,

    Thank you for the clarification. The UCC27710 outputs can operate in a DC on state as explained in the datasheet section 8.4.3 below.

    Consider the HB bias if the HO is expected to operate in a DC on state condition, there will need to be a floating bias supply for HB as the bootstrap HB bias will not maintain HB to HS bias in a DC on state. Also the two driver inputs cannot be high at the same time, or both outputs will be forced to the low state.

    Please confirm if this addresses your question, or you can post additional questions on this thread.

    Regards,

  • Hi Richard.

    Thank you for your kind explain.

    Could you tell me the meaning of the following statement about the protection?

    ''The UCC27710 includes protection features where the outputs are held low when the inputs are left open or when the minimum input pulse width specification is not met.''(p.12 Over view)

    I didn't understand the meaning about the minimum input pulese.

    Sincerely.
    Kengo.

  • Hi Richard.

    How do you think about my question?

    I'd like to receive your advice ASAP.

    Sincerely.

    Kengo.

  • Hello Kengo,

    Sorry for some delay on the response< as I am out of the office for a couple of days.

    You had a question about the minimum input pulse meaning. The UCC27710 has an input filter to reject response to small input pulses to increase the noise immunity of the driver. There is a Ton parameter and Toff parameter, which defines the pulse width on the driver input that will result in the driver output changing state. Ton is the positive pulse width, and Toff is the negative pulse width, the typical specification is 40ns for both Ton and Toff which means any pulse less than 40ns will be rejected by the driver and result in the output not changing state.

    Section 8.4 in the UCC27710 datasheet explains and has timing diagrams of the minimum input pulse function.

    Please confirm if this addresses your question, or you can post additional questions to this thread.

    Regards,

  • Hi Richard.

    Thank you so much for your answer.

    I understood.

    If there are other questions, I will post another thread.

    Sincerely.

    Kengo.