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UCC27712-Q1: UCC27712-Q1 Propagation Delay Matching

Shihab
Expert 1215 points
Part Number: UCC27712-Q1
Other Parts Discussed in Thread: UCC27712

Tool/software:

Hi,

Can you clarify the following timing parameters?

tPDRM Low-to-high delay matching

tPDFM High-to-low delay matching

What is the significance of these parameters?

What is the test circuit used to measure them?

Are they relevant when the driver channels are performing complimentary switching?

Thanks,

Shihab.

  • 0
    TI__Mastermind 23215 points

    Hello Shihab,

    The TPDRM is The difference in the propagation delay of the LO output and HO output on the rising edge of the output, and the TGDFM is the difference in propagation delay of the LO output and HO output on the falling edge of the waveforms. 

    The test conditions is called out in the top of the parameter tables: VDD=VHB=15V, COM ahd HS are connected to ground, for propagation delay measurements the drive load is 0nF. 

    The significance in these parameters will to let the user be aware that there can be some difference in the delays from the LO and HO driver channels. This should be considered when setting the controller dead times. However, in the case of the UCC27712 there is an internal dead time of 150ns so this mismatch of propagation delays is not significant relative to the fixed dead time.

    Regards,

  • 0
    Expert 1215 points

    Hello Richard,

    Thank you for the reply.

    As per the datasheet, both HO and LO cannot be HIGH at the same time. So I was wondering how tPDRM and tPDFM would have been measured.

    Is there matching between propagation delay for the following transitions?. They will be useful when we use the IC for complimentary switching.

    1. Delay matching for HO rising to LO falling (when HI=HIGH and LO=LOW made simultaneously) 

    2. Delay between HO falling to LO rising (when HI=LOW and LO=HIGH made simultaneously) 

    Thanks,

    Shihab.

  • 0 in reply to Shihab
    TI__Mastermind 23215 points

    Hello Shihab,

    That is correct in that the HO and LO cannot be high at the same time. But there will be a delay of the LI to LO rising edge, and a delay of the HI to HO rising edge and the TPDRM is the difference in the delay of these two rising edge events, and the TPDFM is the delay difference of the two falling edge events.

    Regards,