JAJSI72 November 2019 LDC1001
PRODUCTION DATA.
LDC1001 measures the sensor’s frequency of oscillation using a frequency counter. The frequency counter timing is set by an external clock applied on TBCLK pin. The sensor frequency can be calculated from the frequency counter register value (see registers 0x23 through 0x25) in Equation 3:
where
Use Equation 4 to determine the sensor inductance:
where
Example: If ƒEXT = 6MHz, RESPONSE_TIME = 6144, C = 100 pF and measured Fcount = 3000 (dec) (address 0x23 through 0x25)
ƒsensor=(1/3) × (6000000/3000) × (6144)= 4.096 MHz
Using the ƒsensor = 4.096 MHz example for Equation 4, the sensor inductance L = 15.098 µH.
NOTE
The accuracy of a measurement largely depends upon the frequency of the external time-base clock (TBCLK). A higher frequency will provide better measurement accuracy. The maximum supported frequency is 8 MHz.