High speed clocked, latched, and bootstrapped buffer

摘要

From an input signal, a buffer circuit derives an output signal which changes in logic state in synchronism with the rising edges of a first clock and whose value follows the input signal but in opposite logic state. The first clock directly drives the buffer output through a first transistor whose gate is controlled by the output of a NOR-gate. The buffer output is connected to ground through two FET's whose gates are controlled respectively by the first clock and the input signal as sampled by a second clock. The buffer output after being delayed and the input signal as sampled by the second clock are applied to the inputs of the NOR-gate. By adding an FET between the gate of the first transistor and the output of the NOR-gate the bootstrap action caused by the gate-drain parasitic capacitance of the first transistor reduces the delay between the rise of the buffer output and the rising edge of the first clock. A holding circuit may be used to hold the value of the buffer output despite changes in the states of the clocks.