"I want to modify the circuit of the FDC2214 sensor by adjusting the LC resonant circuit to change the frequency of the Fsensor. After modification, I use L = 150uH ± 10%, C = 3300pF ± 5%. The theoretically calculated frequency is around 226KHz (measured actually as 192KHz). The program uses a 2x frequency of the internal reference crystal oscillator, starts in 4-channel acquisition mode, and sets the current to 0.307mA. In practice, the measured capacitance values are very unstable. I don't know if there is an issue with my calculations or if there is a problem with the circuit."
This is my programing！
float Cap_Calculate(uint8_t chx)
{
float Cap;
Data_FDC = FCD2214_ReadCH(chx);
//printf("Data_FDC==%x \r\n",Data_FDC);
Cap = 1556469.63 / (float)Data_FDC;//使用5664576.3；503493.8029;464049.588;160751.492
return (Cap*Cap*100000 -41900);//return (Cap*Cap*100000-25.7)*2;
//printf("Data_FDC==%x \r\n",Data_FDC);
//Cap = 232021045.248/(Data_FDC);
//return (Cap*Cap);
}
