• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Subscribers 82 subscribers
  • Views 738 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TMS320F28335: May I have some question regarding as below?

TAlex Wu
Expert 1200 points

Part Number: TMS320F28335

Dear SIR:

May I have some question regarding as below?

According to TMS320F28335 datasheet page 33 table 5.4 mention as below :

That question is :

(1)If we want to control LED circuit ,(Example: Type A: TMS320F28335 pin----LED---Resistor -----Vcc(3.3V) Type B: TMS320F28335 pin----LED---Resistor -----GND )

    For TypeA: 

    Is that meaning we need calculator that current met (< or =)" TMS320F28335 datasheet page 33 table 5.4" Low-Level output sink current 4mA?

    For TypeB: 

    Is that meaning we need calculator that current met (< or =)" TMS320F28335 datasheet page 33 table 5.4" High-Level output sink current 4mA?

    If we use GPIO28 :[Group 2]

    For TypeA: 

    Is that meaning we need calculator that current met (< or =)" TMS320F28335 datasheet page 33 table 5.4" Low-Level output sink current 8mA?

    For TypeB: 

    Is that meaning we need calculator that current met (< or =)" TMS320F28335 datasheet page 33 table 5.4" High-Level output sink current 8mA?

Or I have any misunderstanding ?

(2)If above mention is "Right and no  misunderstanding",May I have another question as below :

    For TypeA: 

    If calculator that current over ( > )" TMS320F28335 datasheet page 33 table 5.4" Low-Level output sink current 4mA,TMS320F28335 will be damage?

    For TypeB: 

    If calculator that current over ( > )" TMS320F28335 datasheet page 33 table 5.4" High-Level output sink current 4mA,TMS320F28335 will be damage?

    If we use GPIO28 :[Group 2]

    For TypeA: 

     If calculator that current over ( > )" TMS320F28335 datasheet page 33 table 5.4" Low-Level output sink current 8mA ,TMS320F28335 will be damage?

    For TypeB: 

     If calculator that current over ( > )" TMS320F28335 datasheet page 33 table 5.4" High-Level output sink current 8mA,TMS320F28335 will be damage?

(3)What's the meaning regarding TMS320F28335 datasheet page 33 table 5.4 mention that "VOL MAX"?

Thanks

  • 0
    TI__Guru* 95315 points
    Your understanding is correct. However, you need to take into consideration the current limit of the L.E.D as well.

    Yes, you should not exceed the rated current source/sink capability of the GPIO pins.

    VOL(max) - When a GPIO pin is outputting a logic low, the voltage of the pin will be no more than the stated level.
  • 0 in reply to Hareesh Janakiraman
    Expert 1200 points

    Dear SIR:

    Thank for your reply for Question (1),How about Question (2) and (3)?Would you help reply Question (2) and (3)?

    (2)If above mention is "Right and no  misunderstanding",May I have another question as below :

       For TypeA:

       If calculator that current over ( > )" TMS320F28335 datasheet page 33 table 5.4" Low-Level output sink current 4mA,TMS320F28335 will be damage?

       For TypeB:

       If calculator that current over ( > )" TMS320F28335 datasheet page 33 table 5.4" High-Level output sink current 4mA,TMS320F28335 will be damage?

       If we use GPIO28 :[Group 2]

       For TypeA:

        If calculator that current over ( > )" TMS320F28335 datasheet page 33 table 5.4" Low-Level output sink current 8mA ,TMS320F28335 will be damage?

       For TypeB:

        If calculator that current over ( > )" TMS320F28335 datasheet page 33 table 5.4" High-Level output sink current 8mA,TMS320F28335 will be damage?

    (3)What's the meaning regarding TMS320F28335 datasheet page 33 table 5.4 mention that "VOL MAX"?

  • 0 in reply to TAlex Wu
    TI__Guru* 95315 points
    Answers to questions 2 & 3 are already in my previous reply. I have numbered them below:

    (2) Yes, you should not exceed the rated current source/sink capability of the GPIO pins.

    (3) VOL(max) - When a GPIO pin is outputting a logic low, the voltage of the pin will be no more than the stated level.
  • 0 in reply to Hareesh Janakiraman
    Expert 1200 points

    Dear SIR:

    Thank for your reply.

    double confirming as below detail as "==>":

    (3) VOL(max) - When a GPIO pin is outputting a logic low, the voltage of the pin will be no more than the stated level.

    ==>Where can got Vol(Max) value from datasheet?

    Thanks

     

  • 0 in reply to TAlex Wu
    TI__Guru* 95315 points

    Please see section 5.6 in page 38 of SPRS439N. Second row is VOL.

  • 0 in reply to Hareesh Janakiraman
    Expert 1200 points

    Dear SIR:

    Understood and thank for your reply.

    Thanks