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# LDC0851: About the LDC Calculation Sheet

Part Number: LDC0851

We have made arrangements for LDC0851EVM.
We would like to evaluate the EEVM as soon as we get it. Please let us know about the LDC calculation sheet.

d54: din/dout
The calculation sheet says d54=d57/d27, but
Please tell me how d54 and d27 are calculated.

d59: din
The calculation sheet refers to d57, but please tell me the formula for d57.

d60: L
The formula for calculating the self-inductance per layer is in the LDC0851 Sensor Design
Is the formula for self-inductance per layer the same as LDC0851 sensor design, section 2.2, number of turns, equation (2)?

d195: Ltotal
Please tell me the formula for d94 in section 2.13.1 of LDC0851 sensor design.
Is it equation (3) in section 2.13.1 of LDC0851 Sensor Design?

d197: Sensor operating frequency
This refers to d196, and the formula is divided into cases.

d203: RP
This refers to D202, is d202 the AC resistance value?

Thank you very much for your help.

Translated with www.DeepL.com/Translator (free version)

• Hello,

The LDC Calculation sheet has a lot of intermediate calculations and hidden tabs to allow for multiple input options to be available. With that in mind, here is some information about the calculations in question:

• D54: this is the inner diameter of the coil divided by the outer diameter. The outer diameter is from the dout input above. The inner diameter (D59) is calculated based on the outer diameter, turns, trace spacing, and trace width inputs. These are both unit adjusted to make sure they are the same before taking the ratio.
• D60: Yes, this is the same calculation as equation 2 from the sensor design app note
• D195: There are many calculations that go into the total inductance to account for the different layers and PCB thickness.
• D197/196: D196 is an internal calculation step so the result can be unit adjusted.
• D202 is just the Rp before being adjusted for the unit

Best Regards,

Justin Beigel