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LAUNCHXL-F28379D: About Pin Voltage Levels

gG
Intellectual 915 points
Part Number: LAUNCHXL-F28379D
Other Parts Discussed in Thread: C2000WARE

Hello,

I'm using the LAUNCHXL-F28379D device in my embedded system. 

I'm not powering the device via USB interface, instead I used dedicated DC-DC converter has 3.3V output.

In addition to that, I want the device to boost 3.3V to 5V internally. Therefore, i will remove jumpers JP1 and JP2 and i'm going to assemble JP6.

First of all, could you please confirm my above application?

Second, here a question rises. I'm also planning to use SCIBRX and SCIBTX signals in order to communicate with device as shown below. I want to know the output and input signal levels whether they are 3.3V referrenced or 5V.

Could you please inform about this issue?

Third one and last, if I use below configuration as photo.

Consequently, how can i know the signal voltage levels whether they are 3.3V or 5V leveled such as 

1) PWM outputs,

2) ADCIN14,ADCINC3,ADCINB3,..ADCINB2

3) GPIO ports like P124,P124,P58,P59

Actually, I showed in box as below as a summary

Thank you.

  • 0
    TI__Mastermind 40955 points

    Hi gG,

    gG said:
    First of all, could you please confirm my above application?

    Yes, that sounds fine to do.

    gG said:
    Second, here a question rises. I'm also planning to use SCIBRX and SCIBTX signals in order to communicate with device as shown below. I want to know the output and input signal levels whether they are 3.3V referrenced or 5V.

    They are 3.3V referenced.

    gG said:
    Consequently, how can i know the signal voltage levels whether they are 3.3V or 5V leveled such as 

    I'm pretty certain all C2000 signals are 3.3V referenced (circled ones are for certain). All I/O are 3.3V per device datasheet "Recommended Operating Conditions".

    Best,

    Kevin

  • 0 in reply to Kevin Allen18
    Intellectual 915 points

    Dear Kevin,

    Thank you for clear answers.

    Okey, then, what is the purpose of using 5V which is boosted from isolated 3.3V supply? Is it just isolating USB and JTAG?

    Thank you..

  • 0 in reply to gG
    TI__Mastermind 40955 points

    Hi gG,

    Sorry for the delay.

    I'd recommend looking at the schematic for this board to see what the +5V rail is all used for. You can find it within c2000ware at the directory below:

    C:\ti\c2000\C2000Ware_2_01_00_00\boards\LaunchPads\LAUNCHXL_F28379D\R2.0

    5V is used for the following:

    • Powering Op-Amps for ADC reference voltages
    • Pulling up QEP inputs that are 5V (level-shifted to 3.3V on the board)
    • Used for powering boosterpack or external boards that are plugged in

    Best,

    Kevin