Implementing inductive touch buttons with inductive sensing capabilities

Mouser Electronics, Inc., the authorized global distributor with the newest semiconductors, announced that it is now stocking the LDC2114 evaluation module (EVM) for Texas Instruments' (TI) LDC2112 and LDC2114 inductive touch sensing solutions.

A new addition to TI's sensing solutions, the LDC2114EVM features inductive sensing, which detects and measures the presence of a conductor for implementing inductive touch buttons. It also features the LDC2114, a multi-channel, low-noise inductance-to-digital converter optimized for inductive touch applications on monolithic surfaces.

Inductive sensing technology allows the design of touch buttons in a variety of materials, including metal, glass, plastic, and wood, by measuring minute deviations from a conductive target. Sensors for inductive touch systems are coils mounted on a small, compact PCB behind the panel, shielded from the surrounding environment.


▲ LDC2112/LDC2114

The LDC2114EVM, available exclusively from Mouser, can be connected to up to four buttons using a custom coil designed using the WEBENCH Inductive Sensing Designer or using the LDCCOILEVM. This evaluation board provides an integrated and configurable algorithm for button press detection and onboard LED indicators.

TI's LDC2112/LDC2114 inductive touch solutions, available at Mouser, are 1.8 V, multi-channel, low-noise inductance-to-digital converters with integrated algorithms for implementing inductive touch applications. The two-channel LDC2112 and four-channel LDC2114 utilize inductive-capacitive (LC) resonators that offer a wide oscillation frequency range from 1 MHz to 30 MHz and high rejection ratio against noise and interference. Featuring adjustable sensitivity per input channel, the LDC2112/LDC2114 can detect material variations of less than 200 nm, along with a variety of physical button geometries and materials. Higher-resolution measurements also enable implementation of multi-level buttons.

The LDC2112/LDC2114 can operate in an ultra-low power mode of 6µA to optimize battery life. The devices are configured via a 400Hz I2C, and the only external components required for operation are a supply bypass capacitor and a COM pin capacitor to ground. The LDC2112/LDC2114 are ideal for smartphones, wearables, tablets, PCs, virtual reality (VR) headsets, remote controls, HMI panels, and keypads.