Using monolithic multilevel analog detectors
J. Spenser · OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 1980
The detectors now available for use in industrial control systems and other applications combine comparators, a high-impedance input buffer amplifier, a voltage regulator, a scaling resistor network, and output driver transistors on a single monolithic chip for a fraction of the individual cost. One such device is Texas Instruments Inc.'s TL489 five-step linear level detector, each of which can supply a sink current of 80 ma and directly drive either light emitting diodes, filament lamps, or high-level digital logic. Its single power supply produces 10-18 v. The TL489 considerably reduces reference variations and inaccuracies in resistor values, and eliminates output oscillations. The applications of this and similar detectors from National Semiconductor, Siemens Corp., and Exar, in the automotive and other industries, including simple analog-to-digital converters; and calculation of values in designing a circuit that will give a visual indication of how close an oven temperature is to the desired set point are discussed.