FDC2214: The calculation formula of FDC2214 output data

user6519346

Prodigy 151 points

Part Number: FDC2214

In the data manual of FDC2214, its output data DATAx has two formulas.

The first is formula (2) on page 15. The specific formula is shown below.

And the second is formula (9) on page 19. Its specific expression is shown in the following figure.

As you can see, there is a difference between these two formulas. So which of these two is true?

Regards!

over 4 years ago

0 John Miller - Sensing over 4 years ago

TI__Mastermind 40295 points

Pan,

The main difference is the addition of the parameter Chx_FIN_SEL, which specifies a divider of the sensor's resonant frequency.
Some details on the effect of this parameter are given in Table 1, section 10.1.1., and in the device block diagram in Figure 12 of the data sheet.

I don't know why the original author elected to leave CHx_FIN_SEL out of equation (2). It was most likely to make the equations easier to understand.

Regards,
John

0 user6519346 over 4 years ago in reply to John Miller - Sensing

Prodigy 151 points

Thanks.

I know the details about Chx_FIN_SEL.

You mean it should be calculated according to formula (9),right?

Regards.

0 John Miller - Sensing over 4 years ago in reply to user6519346

TI__Mastermind 40295 points

Pan,

You are correct. Please use equation (9) since it will work regardless of the value of CHx_FIN_SEL.

Regards,
John

Sensors

Sensors forum

FDC2214: The calculation formula of FDC2214 output data