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This paper is going to discuss typical requirements for micromachined sensors. The most common examples today are pressure and acceleration sensors. We will discuss the function and applications of pressure and acceleration sensors. There are two differences between accelerometers and pressure sensors: sensor technology and signal conditioning. Pressure sensors employ bulk micromachining techniques where accelerometers use surface micromachining. Pressure sensors are typically signal conditioned with bipolar circuitry. Acceleration sensors use CMOS signal conditioning. We will also explain the electrical characteristics of both pressure and acceleration sensors along with mechanical package styles. We will be focusing our effort on automotive based applications. Some typical applications for pressure sensors in the automotive environment are MAP, BAP, lumbar seat, air bag and tire pressure. The requirements of the MAP/BAP application will also be discussed in detail.

This paper reviews MEMS product applications in a very demanding automotive environment. Our particular interest is in the MEMS inertial and pressure sensors. Specifics of transducer manufacturing technologies will be explained in details. Also advantages and disadvantages of piezoresistive versus capacitive sensing phenomena will be discussed. Finally, main aspects of the packaging effects on the final device parameters and performance are considered too.

A monolithic sensing solution for manifold absolute pressure (MAP) is presented. This work includes examination of design, fabrication, temperature compensation, packaging and electromagnetic compatibility (EMC) testing of the fully integrated monolithic sensor. The circuit uses integrated bipolar electronics and conventional IC processing. The amplification circuit consists of three op-amps, seven laser trimmable resistors, and other active and passive components. Also discussed is a summary of an automotive application MAP sensor general specification, test methods, assembly, packaging, reliability and media testing for a single chip solution.

An Integrated Barometric Absolute Pressure Sensor (IBAP) solution for barometric pressure sensing is presented here. The IBAP is a silicon bulk micromachined monolithic pressure sensor. This work includes an examination of the design, fabrication, temperature compensation, and testing aspects. In addition, options and issues related to the mounting of the IBAP device will be presented. Two techniques, including surface mounting the sensor on the engine control unit (ECU) PWB are discussed.

Electro-Magnetic Compatibility (EMC) is a qualification requirement for automotive electronic components. Meeting for requirement can be a challenge, especially for devices in plastic packages with minimal shielding. EMC has a twofold meaning: a) radiation of electromagnetic energy below a certain level in order to prevent negative impact on electrical performance of surrounding devices, and b) lower susceptibility or greater resistance to the present electromagnetic (EM) signals. Our concern in this paper is the latter one - susceptibility of pressure sensors with integrated signal conditioning including amplification. Electrical performance of these sensors in an environment that is more and more contaminated with EM energy is very crucial for a number of automotive applications. The Integrated Pressure Sensors (IPS) will be used as an example for EMC testing. The EMC test setups and characterization results of the IPS will be discussed.