Understanding Smart Sensors - Nomads.usp

386 Understanding Smart SensorsSensing arrays (continued)integrated system, 265multiple devices, 261–64multiple sensor types, 264–65photodiode, 263Sensing systemsbatteries, 266extending, to the network, 293–95field emission displays, 266–67future requirements of, 315–16illustrated, 2integrated, 265mechatronics and, 249–70next phase of, 311–30voltage, 267Sensitivity, 55comparison, 55improvement analysis, 67–68temperature effect on, 56Sensor interfacesFPAAs as, 94FPGAs as, 94MCUs for, 96–104monolithic design, 95Sensor output, 5, 5–6, 49–69characteristics, 49–57digital, 62–66impedance, 67introduction to, 49low-level, 61low-power, low-voltage, 66–67sensitivity improvement, 67–68signal conditioning, 72summary, 68–69Wheatstone bridge, 50–52Sensorsangular rate, 322artificial intelligence impact on, 168–69bus, 121–22calibrated pressure, 110capacitive, 58characteristics, improving, 61–62chemical, 60–61data sheets, 55dedicated interface circuitry, 11–12defined, 2definitions, 54–57diamond, 41digital output, 62–65EOB, 65gas, 263general model, 5hydrocarbon, 61integration, 38, 113–16manufacturers, 5mechanical crash, 315mechanical measurements, 3media compatibility for, 242microangular rate, 321micromachined, 18microwave, 185monolithic, 235–39multichannel microprobe, 262multiple types of, 264–65nature of, 5–11nonlinearity, 108piezoelectric, 59–60piezoresistive, 6, 39, 65–66, 83, 85plug-and-play, 297–300self-generating, 5semiconductor, 49–69smart. See Smart sensorsstrain-gauge pressure, 50technology choices, 8technology migration path, 10variable-reluctance, 4See also Sensing; Sensor interfaces;Sensor outputSerial communications interface (SCI), 97Serial peripheral interface (SPI), 97, 256defined, 143frequency operation, 256illustrated, 143queued, 143Serial real-time communication system(SERCOS), 132Shear stress strain gauge, 53Shot noise, 65–66Signal conditioning, 72–82circuits, 72, 75integrated, 82–86sensor output, 72separate, 82–86Silicon, 40bulk, 19diaphragms, thin, 67