| 摘要 |
A basic switching circuit combines CMOS and bipolar technique on SiGe basis and operates at a low operating voltage of only slightly more than 2V. To achieve this low operating voltage, switching operation of the circuit is effected by switching a constant current source of the switching circuit on or off using MOS transistors. In addition, the constant current source is implemented using a MOS transistor rather than a bipolar transistor, which basically acts as a controllable resistor. Moreover, the logic levels in the output signal are accurately controlled using a constant current source that is controlled by an operational amplifier and a resistor voltage divider at the output to pull the voltage level down by an amount that corresponds to the logical levels.
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