Understanding Smart Sensors - Nomads.usp

250 Understanding Smart Sensors11.1.1 Integration and MechatronicsThe need for increased control capability in electronic systems is drivingincreased levels of integration in semiconductor electronics, including sensors.A fully integrated silicon system is frequently cited as a goal for the ultimate system.Silicon integration is certainly progressing toward that capability, especiallyfor selected portions of systems. However, the cost and performancecapabilities of higher levels of integration must compete against the componentsthat they would displace. Also, design flexibility and use in several applicationsmust be considered, including such diverse requirements as satisfyingboth domestic and international requirements, simultaneously meeting costsensitive,low-end specifications, and providing feature-sensitive high-endproducts. Furthermore, safety and reliability concerns, such as the potentialfailure modes from a system failure-mode-and-effect analysis (FMEA) can leadto more distributed intelligence when single-point failures cannot be tolerated.In some cases, the system constraints make it desirable to have sensing andpower control elements remote—or at least separated—from the MCU that iscontrolling the system. That allows improved power dissipation, fault detection,and protection from system voltage extremes [2].System partitioning and the determination of how much integrationshould occur within each component are decisions that should be made by aninteractive design team, composed of both system and silicon designers. Integrationfor the output section of the control system is frequently called asmart-power IC. Those integrated solutions have been in volume productionby several manufacturers since the mid-1980s. Understanding their contributionto the control system and how they take advantage of embedded sensing inboth normal operation and fault modes is essential to achieve the systemsapproach and implement mechatronics methodology. This chapter examinessmart-power ICs, more complex sensing in arrays, and systems aspects ofmechatronics.11.2 Smart-Power ICsSmart-power ICs and power ICs (PICs) typically combine bipolar and MOScircuitry with power MOSFET technology to provide direct interface betweenthe MCU and system loads, such as solenoids, lamps, and motors. SmartpowerICs are defined by the Joint Electron Devices Engineering Council(JEDEC) as “hybrid or monolithic devices that are capable of being conductioncooled, perform signal conditioning, and include a power control functionsuch as fault management and/or diagnostics. The scope [of this definition]