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CC3220SF-LAUNCHXL: LPDS with a 3.3V external power supply

Benjamin Alix
Prodigy 250 points
Part Number: CC3220SF-LAUNCHXL
Other Parts Discussed in Thread: CC3220SF

Hi,

I'm doing some measurements on the CC3220SF Launchpad Hardware, when using the on-board USB power and following the swru463a.pdf documentation, I have a consumption of 140µA in idle, which is correct regarding the CC3220SF datasheet (MCU and NWP in LPDS).

However, when I switch to an external power supply at 3.3V following the section 2.5.3 of swru463a.pdf, I measure a consumption of 21mA when in idle.

In the datasheet, a consumption of about 20mA would match a MCU in active mode and a NWP in idle connected mode, so why is it doing this ?

I'm running the exact same software when measuring the consumption on the Launchpad, is there anything else I have to do in order for my MCU to go in LPDS mode ?

  • 0
    TI__Mastermind 27605 points
    HI Benjamin,

    Perhaps there is some dependency in software on hardware connection with a part that is not powered in the second configuration. Then the code is not able to proceed to enter LPDS.

    -Aaron
  • 0 in reply to made4engineering
    Prodigy 250 points
    OK, so I also tried to do the same thing with the power_measure example provided in the SDK and I have the same behavior : when in idle I got 26mA of current consumption with an external supply at 3.3V.

    Could you tell me what could prevent the CC3220 to enter in LPDS in the power_measure example ? Maybe it can help me to understand why I can't enter in LPDS with my application.
  • 0 in reply to Benjamin Alix
    Intellectual 280 points
    After talking to Benjamin, we realized he was using the jumper settings shown in Figure 14 (Section 2.5.2) instead of using the jumper settings in Figure 15 (Section 2.5.3)

    Using the CC3220SF LaunchXL
    I was able to duplicate the higher than expected current using Figure 14.
    I was able to get the expected current of around 100 microAmps using the connections in Figure 15.