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TMS320F28375D Power sequence

Kevin Kemper
Intellectual 370 points

Other Parts Discussed in Thread: TMS320F28375D, CC2650

I'd like to use the delfino (TMS320F28375D) with another low-power microcontroller (CC2650).  The design is power-sensitive so I'd like to use the CC2650 to periodically check sensors while the Delfino is off.  The catch is that the Delfino would also need to access those sensors when it wakes up.   Hibernation seems like the correct way but in the interest of time for a demo I'd like to just power down the Delfino.  I see two options outside of software but it's not clear what the device's behavior will be:

* Disable all regulators to the Delfino.  The issue is that some of the GPIO pins will be driven while the CC2650 chats with sensors.  Will this really be an issue?

* Disable just the core (Vdd).  It's not clear what the behavior is for this.  Will it draw lots of power if it's just left like this?  Is it still bothered by having it's IO driven?

Thanks,

~Kevin

  • 0
    TI__Expert 7885 points
    Hello Kevin,

    "Disable all regulators to the Delfino. The issue is that some of the GPIO pins will be driven while the CC2650 chats with sensors. Will this really be an issue?"

    It specifically states in the DS: "Before powering the device, no voltage larger than 0.3 V above VDDIO should be applied to any digital pin, and no voltage larger than 0.3 V above VDDA should be applied to any analog pin." Violating this requirement can reverse bias internal transistors and result in unpredictable behavior.

    "Disable just the core (Vdd). It's not clear what the behavior is for this. Will it draw lots of power if it's just left like this? Is it still bothered by having it's IO driven?"

    I don't have exact values for how much power will be drawn in this state as it is not a standard and/or tested device state. The requirement for the IOs is only with respect to the VDDIO supply so I don't believe there will be an issue there, but let me confirm internally that keeping the device in this state for an extended period of time is acceptable.

    Best Regards,
    Adam Dunhoft