Inductance-to-digital converter: a new approach in position and motion sensing

September 16, 2013 // By Christoph Hammerschmidt
Texas Instruments unveiled a new data converter category that uses coils and springs as inductive sensors to deliver higher resolution, increased reliability, and greater flexibility than existing sensing solutions at a lower system cost.

Inductive sensing is a contactless sensing technology that 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. TI's first inductance-to-digital converter (LDC) product is the LDC1000EVM, a combination of the sensor and an integrated MSP430F5528 microcontroller.

Applications for inductive sensing range from simple push buttons, knobs, and on/off switches to high-resolution heart rate monitors, turbine flow meters, and high-speed motor/gear controllers. Given their versatility, LDCs can be used in many different markets, including 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.

Key benefits of LDC technology:

  • 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.

Wide range of application 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, is available to evaluate the device and can be purchased now for US$29.00.

For more information visit www.ti.com/analogindustrial-pr.