The LDC3114 is a multichannel device. The italic n in the parameters below refers to the channel index:

1. Select system-based options:
   • Select Normal or Low Power Mode of operation by setting the LPWRB pin to V_DD or ground, respectively. Configure the enable bits for all channels in Register EN (Address 0x0C).
   • Select the polarities of OUTn and INTB pins by configuring Register OPOL_DPOL (Address 0x1C) and Register INTPOL (Address 0x11).
   • Configure the sensor frequency setting in Registers SENSORn_CONFIG (Addresses 0x20, 0x22, 0x24, 0x26).
2. Choose the sampling rate (80, 40, 20, 10, 5, 2.5, 1.25, or 0.625 SPS) based on system power consumption requirement, and configure Register NP_SCAN_RATE (Address 0x0D) or Register LP_SCAN_RATE (Address 0x0F).
3. Choose the button sampling window based on power consumption and noise requirements (recommended: 1 ms to 8 ms). While a longer button sampling window provides better noise performance, 1 ms is typically sufficient for most applications. Set SENCYCn and LCDIV in Registers SENSORn_CONFIG (Addresses 0x20, 0x22, 0x24, 0x26) and Register LC_DIVIDER (Address 0x17) in the following steps:
   • Calculate LCDIV = ceiling (log₂ (f_SENSORn × t_SAMPLEn) – 12), where f_SENSORn is the sensor frequency in MHz, t_SAMPLEn is the button sampling window in µs.
   • If LCDIV < 0, set it to 0.
   • Adjust SENCYCn to get desired t_SAMPLEn according to t_SAMPLEn = 128 × (SENCYCn + 1) × 2^LCDIV / f_SENSORn.
4. Calibrate gain in the appropriate Registers GAINn (Addresses 0x0E, 0x10, 0x12, 0x14). The gain setting can be used to tune the sensitivity of the touch button. GAINn is a 6-bit field with 64 different gain levels corresponding to normalized gains between 1 and 232. A good mechanical and sensor design typically requires a gain level of around 32 to 50, corresponding to relative gains of 16 to 76 (normalized to gain level of 0). Use the following sequence to determine the appropriate gain for each button:
   • Apply minimum desired force to the button.
   • Read initial DATAn value after the button press. Note that the baseline tracking will affect this value.
   • Calculate gain factor required to increase DATAn to the programmed threshold (default is 160).
   • Look up the Gain Table to find the required gain setting.
5. Enable special features to mitigate button interference if there is any, in Registers BTPAUSE_MAXWIN, TWIST, COMMON_DEFORM (Addresses 0x16, 0x19, 0x1A).

For more information on inductive touch system design, including mechanical design and sensor electrical design, refer to Inductive Touch System Design Guide.