EVM430-FR6047: Can I use 2nF for the interface of transducers?

Jack Son

Part Number: EVM430-FR6047

Hi, I am testing with EVM430-FR6047 and my own design. I have two questions.

1. When I tested with EVM430-FR6047 board, I found out the value of C11,C12 have a relationship with time of receive Bias.

for the receive signal amplifier, If I change the C11,C12 to 2nF, is it no problem? and Can I get the value limit of capacitance? Min and Max

2. I hope to receive the TOF value and convert (double type) from FR6047, but I can't understand the "IQ40" fixed point.

Can I get the bit information of IQ40? following is what I understood but the result is not accurate.

Thanks for reply.

over 1 year ago

0 Cash Hao11 over 1 year ago

TI__Mastermind 32825 points

Hi,

1. You can change the C11 and C12 simultaneously as you want. The R16, C11/R17, C12 are used to create an oscillating circuit for the transducer. You can change the value and there is no limit for those values.

2. You can call the USS_getResultsInFloat() to convert the IQ format data to float for you. And if you want to understand about the IQ format. You can refer to this link. https://software-dl.ti.com/msp430/msp430_public_sw/mcu/msp430/IQmathLib/latest/exports/MSP430-IQmathLib-UsersGuide.pdf

Best regards,

Cash Hao

0 Jack Son over 1 year ago in reply to Cash Hao11

Prodigy 30 points

Thank you. Cash. I can understand IQ format as your link.

But I found that the result value of (iq40TotalTOF_UPS - iq40TotalTOF_DNS) is not same to iq44DeltaTOF.

How can I find the equation about iq44DeltaTOF?

BestRegards.

0 Cash Hao11 over 1 year ago in reply to Jack Son

TI__Mastermind 32825 points

Hi,

In the USS library, we are using correlation method to calculate the dTOF. And uses lobe method to calculate the absTOF. They are two independent method, so the dTOF does not equal to (absTOF_UPS - absTOF_DNS).

You can refer to this link for more details.

https://www.ti.com/lit/ug/tidudn0/tidudn0.pdf

Best regards,

Cash Hao

0 Jack Son over 1 year ago in reply to Cash Hao11

Prodigy 30 points

Hi Cash.

Thanks for your Reply. I will read your guide doc.

BestRegards.

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EVM430-FR6047: Can I use 2nF for the interface of transducers?