Texas Instruments has developed a chip for contactless touch free sensing solution for multiple number of applications. The device/chip called inductance to digital converter is an analog to digital converter integrated device, which converts the measured analog inductance into digital data. The inductance of the simple coil which can be formed on a PCB or a metal spring varies when any material come close to the coil. The change in the electromagnetic energy in the inductance is fed to a set of amplifier and ADC to produce digital data proportional to the change in inductance.
This single chip inductance to digital converter can be used to measure the position, motion, or composition of a metal or conductive target, as well as detect the compression, extension or twist of a spring.
Applications for inductive sensing suggested by TI includes simple push buttons, knobs, and on/off switches to high-resolution heart rate monitors, turbine flow meters, and high-speed motor/gear controllers. Inductance to digital converters find use in automotive, white goods, consumer electronics, mobile devices, computing, industrial, and medical.
"LDC technology enables engineers to create sensors using low-cost and readily available PCB traces or metal springs. LDCs provide high-resolution sensing of any metal or conductor – including the human body," said Dave Heacock, senior vice president of TI Silicon Valley Analog. "LDCs provide system designers with a new platform for developing breakthrough solutions to difficult system problems. We can't wait to see what they come up with."
Key benefits of LDC technology as per TI:
Higher resolution: Enables sub-micron resolution in position-sensing applications with 16-bit resonance impedance and 24-bit inductance values.
Increased reliability: Offers contactless sensing that is immune to nonconductive contaminants, such as oil, dirt and dust, which can shorten equipment life.
Greater flexibility: Allows the sensor to be located remotely from the electronics, where PCBs cannot be placed.
Lower system cost: Uses low-cost sensors and targets and does not require magnets.
Limitless possibilities: Supports pressed foil or conductive ink targets, offering endless opportunities for creative and innovative system design.
Lower system power: Consumes less than 8.5 mW during standard operation and less than 1.25 mW in standby mode.
The LDC1000EVM, which includes an MSP430F5528 microcontroller (MCU), is available to evaluate the device and can be purchased today for US$29.00.
System designers can create a custom sensor coil and configure the LDC in seconds with TI's new WEBENCH Inductive Sensing Designer. The online tool simplifies the sensor coil design process and provides configuration settings for the LDC based on the coil's characteristics, application requirements and system performance needs. The optimized design can be easily exported to a variety of popular CAD programs, to quickly incorporate the sensor coil into the overall system design.
Package, availability and pricing: The LDC1000 is available to order today in a 16-pin, 4-mm by 5-mm SON package for US$2.95 in 1,000-unit quantities. An automotive-qualified version will be available the first half of 2014.