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MSP430FR6047: Power Management for Ultrasonic Water/flow meter application

Other Parts Discussed in Thread: MSP430FR6047, TPS61094, TPS61291, TPS62740

Our company will use an MSP430FR6047 MCU with a sub 1 GHz communication feature for ultrasonic water/flow meter applications. And for the power management option, we have two best alternatives.

1) Using TPS61094 Buck-Boost as per this application note -> 

2)  Using TPS62740 Buck and TPS61291 Boost together as per this application note -> 

To proceed with one of those, we must first determine which one is superior in all aspects, particularly performance and reliability. Could someone please assist me with this? 

And if there is another best power management option/ part number, please share the link here.

Last but not least, which is better suited for battery-powered circuits, DC-DC Buck or LDO?

  • Hi Ashenafi,

    The TPS62740 buck is a good low IQ device for supplying the MCU in this application, as described in the 2nd App note. The EMI performance of this device should also be good due to slower switching slew rates.

    The TPS62840YBG is also an alternative to the TPS62740.

    I shall move the thread to the group responsible for the TPS61292 to check if there is a newer device for this application.

    Best regards,


  • Hi Varun,

    Thank you for your thoughtful response.

    In that case, you're saying that choice number 2) is better than choice number 1), right?

    I'll wait for your response on TPS61292.

  • Hi Ashenafi,

    The choice between both solutions depends on the rails you want to power. For example solution 2 provides 2 output rails, one to power the MCU at a lower voltage from the buck output and another one to power the PA from the boost output. Unfortunately there isn't an efficiency graph in the 2nd solution app note to compare efficiencies between both solutions. 

    Best regards,


  • Ok, Thank you Varun.