Inductor sensor interface ICs replace Hall devices

August 03, 2015 // By Graham Prophet
The first device in new family of smart sensor interface ICs, Microsemi’s LX3301A is, says the company, the first inductive sensor IC based upon LVDT (linear variable differential transformer) architecture implementations on PCBs: Microsemi designed it for automotive and industrial applications.

The LX3301A sensor interface IC’s use of LVDT principles, gives superior immunity to noise and interference. Microsemi says its technology can replace Hall-effect sensors currently used in the marketplace, as these magnet-based sensors are susceptible to external magnetic fields and/or metal objects in close proximity. Inductive technology eliminates the magnet, thereby improving immunity to such interference.

The device is suitable for a variety of applications related to control systems and industrial automation, specifically linear displacement measurement (fluid level sensing, gear position for transmission actuator position and brake lamp switch/proximity detection) and angular motion measurement (robotic arm position, rotating shaft position, pedal position and rotary controls). It also meets strict automotive application requirements, including AECQ100-certified grade 1, ISO26262 compliance and production part approval process (PPAP) documentation support.

Features include:

  1. Contactless sensing (high reliability);
  2. Embedded 32-bit processing engine with 12 kB program memory;
  3. Two sensor input channels with integrated demodulator;
  4. Internal oscillator with frequency range of 1 to 5 MHz;
  5. Dual 13-bit ADC with sample rates to 2 kHz;
  6. User-programmable 16x16-bit non-volatile configuration memory;
  7. Automotive support team to ensure successful adoption.

The LX33xx sensor IC family can be used with Microsemi’s motor drive reference design using the SmartFusion2 system-on chip (SoC) field programmable gate array (FPGA) and a motor control IP suite to process the sensor inputs and motor drive algorithms. The sensor inputs can be connected to the motor control evaluation board.