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.

TMS320F28377D: TMS320F28377D

Part Number: TMS320F28377D

We are planning to use TMS320F28377D for our project.

MCT6 opto couplers are connected to the output pins of the MCU that will draw an input forward current of 10mA per output, and 22 outputs will be made to on continuously.

Is this safe within the operating conditions?

If not please help selecting any other optocoupler IC which can be used in place of MCT6, which takes less Input forward current to operate.

  • Hi Vineesh,

    Is this safe within the operating conditions?

    No this wouldn't be safe. F2837x device I/Os are spec'd at 4mA output source and sink, see datasheet Electrical Characteristics for this detail.

    Best,

    Kevin

  • Is there any other recommendation to use as optocoupler, I would like to drive ULN2803 using the output of the optocoupler?

  • Hi Vineesh, 

    The ULN2803A has a sink current range of (0.93mA-1.35mA) where the F2837x device I/Os are spec'd at source current of 4mA. This can be used for your application.  

    Let me know if you have any further queries. 

    Best, 

    Uttam

  • Thank you for the reply. I would like to use MCT6 for isolation and ULN2803 for giving the load current. will this circuit work?

  •   I would like to use MCT6 for isolation and ULN2803 for giving the load current. will this circuit work?

  • Hi Vineesh, 

    Based on my understanding the MCU output (sourced 4mA/ pin) goes to MCT6 as an isolation and then follows with ULN2803A (has sink current max at 1.35mA) - From the specific datasheet information available on TI.com.

    As per your requirement, to use 22 output each of 10mA will not be feasible.

    If in case this application can modify with <4mA/pin as MCU output and the ULN2803A output clamp current (max < 500mA). On the outline it seems it could work.

    It would be better to check these first:

    1. With MCT6 (has a current transfer ratio of 50%) and its impact on ULN2803A weather the load current requirements are reached or not.

    2. to comment on the application of ULN2803A. - please go through the NOTE below:

    If you need more application specific details on ULN2803A. I would recommend reaching out to ULN2803A experts on E2E forum.

    Let me know if you have any specific questions related to MCU (F28377D).

    Best,

    Uttam