Hi TI technical support team,
Here are my questions, could you help answer? thanks.
1, Datasheet says "calculate gain factor required to increase DATAn to the programmed threshod(default is 160)" in chapter 8.2.1.2, but I couldn't find how to calculate gain factor required.
2, For the calculation tool "Excel_FEMM_v1p29.xlsm", I always can't set the Frequency, Rp, Q in the recommended range at the same time.
Jianyong,
Thank you for reaching out with your question about LDC3114. I've attempted to respond to your questions below. Please be aware that any follow up responses will likely be delayed due to end of year holiday schedules. We will try to respond to any further questions as quickly as possible.
Table 7-54 shows the decimal value of the register and the corresponding Normalized Gain Factor. The specific sensitivity required for any button will vary based on the mechanical rigidity, but the goal should be to set the gain in order to reliably register above the input threshold.
LDC3114 requires sensor frequency to be between 5-30 MHz. The typical Q factor should vary between 5-30, and Rp should range between 350 Ohms - 10 kOhms.
Using the calculator tool I was able to determine that these values were able to keep within the parameters
You may have to carefully consider and adjust your coil parameters if you are not able to select an LC combination that will work appropriately with your setup. The calculator can be useful to quickly check for target inductance values before proceeding with a full design.
Thanks,
Scott
