The LDC3114 is a hybrid multichannel, low-noise, high-resolution inductance-to-digital converter (LDC) optimized for inductive touch applications as well as linear position sensing. Button presses form micro-deflections in the conductive targets which cause frequency shifts in the resonant sensors. The LDC3114 can measure such frequency shifts and determine when button presses occur. With adjustable sensitivity per input channel, the LDC3114 can reliably operate with a wide range of physical button structures and materials. The high resolution measurement enables the implementation of force level buttons. The LDC3114 incorporates customizable post-processing algorithms for enhanced robustness.

The LDC3114 additionally implements a raw data access mode. The MCU can read directly the data representing the effective inductance of the sensor and implement further post processing. In this mode, additional post processing features such as baseline tracking and algorithms for false button detection are ignored. This mode is useful for linear or rotary position sensing with inductive sensors while having excellent EMI performance across wide range of applications. This mode can also be used to measure the micro-deflection for button-like applications as well.

The LDC3114 can operate in an ultra-low power mode for optimal battery life, or can be toggled into a higher scan rate for more responsive button press detection for game play or other low latency applications. The LDC3114 is operational from –40°C to +125°C with a 1.8 V ± 5% power supply voltage.

The LDC3114 is configured through 400-kHz I²C. Button presses can be reported through the I²C interface or with configurable polarity dedicated push-pull outputs. Besides the LC resonant sensors, the only external components necessary for operation are supply bypassing capacitors and a COM pin capacitor to ground.