Inductance to digital converter technology to bring sensor versatility
A chip introduced by electronics specialist Texas Instruments is set to allow a range of devices to function as inductive sensors. The device, called the LDC 1000, works with coils and springs to bring higher resolution, increased reliability and greater flexibility than existing sensing solutions.
According to the company, inductive sensing can be used to measure the position and motion of a metal or conductive target. As well as detecting the compression, extension or twist of a spring, the approach is also said to be capable of discriminating between different metals in a composite.
Jon Baldwin, sensor signal path product line manager for TI, said: "What's good about this technology is all the cool things you can do with it. It gives designers opportunities to create different things, such as pushbuttons that respond to a finger and nothing else. You can even use a spring as a sensors, just by adding two wires and a chip."
Applications for inductive sensing are to be found in a range of sectors, including automotive, white goods, consumer electronics, industrial and medical. "These applications share the common need to detect moving parts," Baldwin continued.
In particular, TI is targeting applications which currently use Hall sensing. "Hall sensors have become de facto for position sensing in harsh environments, but this requires a magnet, whose performance can be limited by drift over temperature and time," Baldwin noted. "And the magnets can be expensive."
The approach requires a resonant circuit to be established using the inductance of a coil and a capacitor. When a metal object is detected, the resonant frequency changes.
The LDC1000 is supplied in a 16pin 4 x 5mm package and will be available in an automotive qualified version. Designs are supported by an evalution board and a Webench design tool.
