| 摘要 |
Differential buffers are used in a voltage-controlled oscillator to provide pairs of complementary phase signals. The preferred arrangement includes a ring of the differential buffers. Each differential buffer has a current control input, and the current control inputs of the buffers are all connected to a control voltage input to simultaneously adjust the propagation delay of each of the buffers. In contrast to a conventional ring oscillator, which has an odd number of stages, a ring oscillator made of differential buffers can have an even number of buffers to provide a number of phases that is a multiple of four. The differential buffer preferably includes a pair of CMOS inverters sharing a common PMOS current sourcing transistor and a common NMOS current sinking transistor.
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