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F28M36P63C2: Routing Cmparator Output to PWM Trip zone

sai k
Prodigy 60 points

Part Number: F28M36P63C2

Can I use comparator output as a trip input to PWM module without any hardware connections( It should be instantaneous i.e., as available in piccolo controller 28030 where i can use comparator output as a DC event generator which in turn used as a source for PWM Tripping)..

  • 0
    TI__Mastermind 42195 points

    Edit 2/6/2018.

    "For F28M36 devices there is no need for hardware connections." is incorrect, external hardware connections are required.

    ==============

    Sai,

    For F28M36 devices there is no need for hardware connections. The delay between a Comparator output and a PWM trip is specified as a "typical number" and can be found in table 5-38 (Electrical Characteristics of the Comparator/DAC) of the Data Sheet. The specific line item is "Comparator response time to PWM Trip Zone (Async)" which has a TYP of 30 nS.

    Regards,
    Cody 

  • 0 in reply to Cody Watkins
    Prodigy 60 points

    Cody Watkins,

       In the data sheet it is given that we need to route them externally(6.5.3 para2). Could you please go through it once...

        The doubt araised because in the same data sheet and in a code snippet(example 7.14),  comp1out is used directly to generate a dc event which then used to trip pwm. How is this possible??

  • 0 in reply to sai k
    TI__Guru 62975 points
    Sai,

    The datasheet description that Cody referenced is a mistake. The comparator asynchronous response time is correct, but the signal unfortunately does not reach the PWM trip zone internally. An external pin loop-back connection is required to complete the signal chain. I will ask to have this corrected.

    Where did you see the example code?

    -Tommy
  • 0 in reply to tlee
    Prodigy 60 points

    Tlee,

      I have seen the example code in technical reference manual(spruhe8d.pdf)..# please hv a look at the code snippet in manual..

  • 0 in reply to sai k
    TI__Guru 62975 points
    Sai,

    I see it. Yes, that is also a mistake.

    -Tommy