MSP430FR60431: power consumption calculation

Hi 

The 3uA is come from our water meter EVM embedded msp430fr6047 that is the same family with MSP430FR6043. More detail http://www.ti.com/lit/ug/tidudn0/tidudn0.pdf You can check you hardware compare with our EVM to see if any other power consumption on your board.

But even with 10uA, that is possible  to make the battery life for 10 years. For most popular use battery in water meter is 18650 which have 2600mah.

2600/(10*10^-3)=260000h   260000/24=10833 days 10833/366=29years

Which kind of battery do you use?

Best regards

Gary 

the data sheet of MSP430FR6043 states in the first page

Approximately 3-μA overall current consumption with 1 set of results per second

and the TI Designs: TIDM-1019

Ultrasonic Sensing Subsystem Reference Design for Water Flow Measurement

page number 37 describes the details of this 3uA per 1 second

is this means that i will get only 1 set of results per hour?!!!

and is this acceptable for OIML R49 stranded?

thanks

Hi,

Ahmed, I'm working on a similar project if you want to co-operate I have no problem.

yes you have a mistake in your calculations if the system consumes 3-μA overall current consumption with 1 set of results per second which means 10.8-mA, not 10.8-μA.

so the calculation will be for 2600mAH battery if the 3-μA is for one dTOF :

2600/10=260h   260/24=10.833 days only which very hight power consumption.

I'm facing the same issue and can't calculate the power consumption.

the question now is for Gary, is 3-μA for calculating one dTOF or 3600 dTOF?

if the 3-μA is for 1 dTOF please provide me with a battery which can hold this system for 10 years as TI states that the metering SoC are best in class.

last thing I need an updated version of the user guide that state the power consumption per hour to rely on it as convince material for my client since both of us works with TI because TI is a trustful company.

Hi Ahmed

Thank for your trust. I have some questions about your point

Have you read the section of 3.2.2.5 of the this document http://www.ti.com/lit/ug/tidudn0/tidudn0.pdf ?

The average of the current is 3.83 uA in the picture 26

I don't know what's meaning of " if the system consumes 3-μA overall current consumption with 1 set of results per second which means 10.8-mA, not 10.8-μA". Why it is 10.8mA? Can you tell me how you get it?

Best regards

Gary

it is ok

3.8uAX3600 = 13.79mA/h

is that calculation is correct?

if correct this means that 330.9mA/day and 187.3A/year!!!

you are taking about 10years of battery life which is not possible

thanks

No, that is not you the way you calculate.

You can see the meaning of the mAh:

For instance, a 3000 mAh battery could power a device drawing 100 mA (average current) for 30 hours. A device drawing 10 uA would last only 300000 hours.

Best regards

Gary

this means that power consumption is 3.8uA per hour for 1 set of reading per second (3.8uA per 3600 reading in 1 hour)?

if this correct please clear this information on datasheet as it is so confusing for reader.

please confirm that for me

thanks

Hi

I think we all going to circles here.

let me ask you, Gary, more simple question.

if I have 1000mAh battery how long it will keep the ultrasonic metering system on(calculating dTOF)?

or

how much amperage the MCU will consume to do 1 dTOF and 3600 dTOF?

regards,

Ahmed

Hi

Please clear what's the meaning of average current here. The average current is regardless with the time.(Please don't multiply 3600) The mAh is use the average current. I afraid you have not fully under stand the meaning of mAh. You can see this page https://www.ubergizmo.com/what-is/mah-milliamp-hours/

Please watch the video carefully for the meaning of the mAh. Thanks

Best regards

Gary