TMS570LC4357: TMS570LC43x current measurement

Federico Silva

Part Number: TMS570LC4357
Other Parts Discussed in Thread: TM4C129ENCPDT, ENERGYTRACE

Hello,

I've read somewhere that there is a shunt resistor and a differential amplifier to measure current consumption of the microcontroller. However, I don't know if that's true or not, because the schematics I found aren't for this launchpad board. Does anyone know which output has that signal?

Thanks,

Federico

over 7 years ago

0 Federico Silva over 7 years ago

Intellectual 795 points

I'm sorry for the inconvenience. I found the shunt resistor and the amplifier: they are on page 11 of processors.wiki.ti.com/.../LAUNCHXL2_570LC43_RM57L_SCHEMATICS.pdf

There the output is HERCULES_ICORE/15.1B. The problem is I don't find it on the launchpad; which pin is it?

Thanks

0 Chuck Davenport over 7 years ago in reply to Federico Silva

TI__Guru 59540 points

Hello Federico,

I don't believe the Launchpads include this feature. You are welcome to review the schematics of the Launchpad on their associated wiki as well to be certain. The schematic is available for download at this link: processors.wiki.ti.com/.../LAUNCHXL2-570LC43

0 Federico Silva over 7 years ago in reply to Chuck Davenport

Intellectual 795 points

Hello Chuck,

on the schematic, U6 is a differential amplifier whose input voltage is the voltage drop on a shunt resistor, which is in series with the 1.2V voltage regulator output. The problem is I don't know to which pin does the amplifier go; it says HERCULES_ICORE/15.1B.

Thanks,

Federico

0 Wilson43819 over 7 years ago in reply to Federico Silva

Prodigy 170 points

Greetings,

Take a look at Pin 15 of U7A (TM4C129ENCPDT).

-Wilson

0 Federico Silva over 7 years ago in reply to Wilson43819

Intellectual 795 points

Yes, I see it's connected to the debug uC.

Now, is it possible to use a jtag debug probe or something like that to measure the current?

Thanks

0 Federico Silva over 7 years ago in reply to Federico Silva

Intellectual 795 points

Does this debugger www.ti.com/.../TMDSEMU200-U works for the current consumption?

Thanks

0 Jan Cumps over 7 years ago in reply to Federico Silva

Guru 15740 points

I believe it's linked to the debugger because it's supposed to be used with CCS EnergyTrace.

0 Federico Silva over 7 years ago in reply to Jan Cumps

Intellectual 795 points

But Energy Trace supposedly only work with MSP430/2, doesn't it?

0 Jan Cumps over 7 years ago in reply to Federico Silva

Guru 15740 points

Yes. But I can't any other reason why TI made a similar configuration as on the MSP432 LaunchPads ...

0 Chuck Davenport over 7 years ago in reply to Federico Silva

TI__Guru 59540 points

Hello Frederico,

YOu are correct that Energy Trace is not intended for use with Hercules. I will review this specific line item in the schematic to see if I am able to determine its purpose if for the TMS570 launchpad.

0 Chuck Davenport over 7 years ago in reply to Chuck Davenport

TI__Guru 59540 points

Hello Federico,

I had a closer look at the signal and too am not aware of the purpose. I would speculate that it has something to do with being used as a reference some sort of power monitoring feature on another device. Perhaps it was put there in hopes that the power monitoring feature would be available some day.

The only thing I can recommend is to the board layout and scematic files to locate somewhere you can tap into the supply with an inline jumper to measure the current directly. For example, can you lif the pin of the regulator output and supply the voltages from an external supply? This would allow you greater access to the voltage and current measurements. In doing this type of modification to the board I would be very careful relative to PG conditions and sequencing. You might also consider adding a jumper to measure the output at the supply pin by lifting the pin and adding blue wire mods to access.

0 Federico Silva over 7 years ago in reply to Chuck Davenport

Intellectual 795 points

Hello Chuck,

thanks for the answer. I think I'll tap into the supply and measure from there.

Thanks,
Federico

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TMS570LC4357: TMS570LC43x current measurement