| 摘要 |
<p>To avoid forward biasing the diodes within an N-channel transistor, the body (36) and source (38) of the N-channel transistor (34) are switchably connected via a high-voltage FET (42). The gates (46, 50) of the N-channel transistor (34) and high-voltage transistor (42) are connected together so that both transistors are on or off simultaneously. When both transistors are on, the high-voltage transistor (42) shorts the body (36) and source (38) of the N-channel transistor (34). When both transistors are off, the body (36) and source (38) of the N-channel transistor (34) are disconnected and a third transistor (56) couples the body to a reference potential. The N-channel transistor (34) and high voltage transistor (42) share a common body in a semiconductor substrate. The source (38) of the N-channel transistor (34) provides an output terminal for the circuit. A number of these devices, each connected to a different supply voltage, can be connected to the same output terminal and selectively energized to form a voltage multiplexer.</p> |
