Programmable interface suits automotive sensors

Edited by the Electronicstalk editorial team May 27, 2005

Melexis has developed a novel, versatile, fully integrated and programmable sensor interface solution for automotive and industrial applications.

Melexis has developed a novel, versatile, fully integrated and programmable sensor interface solution for automotive and industrial applications.

The MLX90320 provides amplification, calibration and temperature compensation for virtually all kinds of resistive bridge type sensors including pressure transducers, strain gauges and position sensors.

The MLX90320 can help design engineers to optimise their application in terms of cost, space and time to market.

With very few additional components the MLX90320 will amplify an analogue ratiometric input signal to achieve the desired output signal.

This output signal can be corrected for sensitivity and offset errors due to temperature effects.

The ASIC calibrates the sensor output by nulling the offset voltage and by applying the appropriate signal gain to calibrate the output voltage span between 0 and 5V.

Error calibration is accomplished via various DACs.

The digital coefficients, which determine the calibration parameters, are stored in an on-chip EEPROM.

Both gain and offset have coarse and fine DACs, allowing a very accurate calibration over a wide range of input errors.

An operating temperature range of -40 to +150C as well as various implemented clamping detection and fault/diagnosis modes, overvoltage and reverse polarity protection make the MLX90320 the perfect fit for automotive applications.

Melexis' "programmable through connector" concept for high-volume implementations, enables programming in the production environment post assembly.

Among the possible applications are pressure sensors, steering systems (torque sensors), safety restraint systems (seat occupant detection), braking systems (ABS, force), comfort systems (air conditioning) and engine management (injection).

MLX90320 samples are available from stock in SSOP14 packages and a development board with Microsoft Windows compatible control and EEPROM programming software is also available.