| 摘要 |
A voltage selector circuit determines the highest of at least two available input voltages, and connects the highest voltage to an output terminal. The circuit includes a comparator having first and second FETs having their sources connected to first and second input voltages (V1 and V2), and which are biased with first and second bias currents. The first FET is driven on regeneratively when V1>V2, and the second FET is driven on regeneratively when V2>V1. A first switch connects V1 to an output terminal when the first FET is driven on, and a second switch connects V2 to the output terminal when the second FET is driven on. First and second diode-connected FETs are connected below the first and second FETs and carry their respective bias currents, thereby limiting the voltage swings on the FETs' gates and providing control over hysteresis.
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