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Maxim > Design Support > Technical Documents > Application Notes > Amplifier and Comparator Circuits > APP 942
Maxim > Design Support > Technical Documents > Application Notes > Miscellaneous Circuits > APP 942
Keywords: load switcher, current, low power
APPLICATION NOTE 942
Load Switcher Draws Only 6µA
Jul 04, 1996
Abstract: Taking advantage of the IC's very low quiescent current, this circuit enables a small signal of
±1mV or more to switch relatively large load currents.
Figure 1's circuit draws only 6µA, but it enables a small signal of ±1mV or more to switch relatively large
load currents. It takes advantage of the IC's very low quiescent current—1.2µA (max) per amplifier (less
than a typical battery's self-discharge)—which is able to flow through R1 without turning on Q1. When
operated with a sensing coil (as shown) and stimulated by a magnet, the circuit performs the function of
a reed switch, but with greater sensitivity. Other applications include alarm systems, bipolar threshold
sensing, and audio volume switching.
Figure 1. This load switcher enables a small signal to turn on a much larger load current.
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