Abstract: An analog finite impulse response (“FIR”) filter generates a continuous time output using a chain of tunable delay elements. The tunable delay elements generate a time delay in an input signal. A calibration circuit, consisting of a control loop, tunes the delay elements to provide precision in the time delay response of the delay elements. The control loop generates a delay adjustment, based on the period of reference signals, and the phase adjustment is used to tune the parameters of the delay elements. The tunable delay elements may comprise any combination of transmission lines, lumped elements and semi-lumped elements.
Abstract: A logic circuit employs a shunt peaked technique to enhance the switching speed of the circuit without an increase in power dissipation. A differential logic gate implements a digital circuit function. The shunt peaked logic circuit includes two resistive and two inductive elements. For each differential output line, a resistive element is coupled in series to an inductive element so as to couple the circuit power supply voltage to a differential output line. Under this configuration, the bandwidth of the logic circuit is increased without an increase in power consumption. The logic circuit may be implemented using CML or ECL logic. Techniques for improving large signal performance for active shunt-peaked circuits are also disclosed.
Abstract: A synchronous circuit implements a bypass mode for use in conjunction with an inductive-capacitive (“LC”) buffer. The LC buffer receives differential conventional clock signals, and generates buffered differential conventional clock signals. A synchronous circuit, such as a latch, includes at least two clock receivers. The conventional clock signal is input to the first clock receiver, such as a transistor, and an auxiliary clock is input to a second clock receiver. The conventional clock signal provides timing for the synchronous circuit under a normal mode of operation, and the auxiliary clock signal provides timing for the synchronous circuit under a test mode of operation at a frequency lower than the conventional clock signal.
Abstract: A logic circuit employs a shunt peaked technique to enhance the switching speed of the circuit without an increase in power dissipation. A differential logic gate implements a digital circuit function. The shunt peaked logic circuit includes two resistive and two inductive elements. For each differential output line, a resistive element is coupled in series to an inductive element so as to couple the circuit power supply voltage to a differential output line. Under this configuration, the bandwidth of the logic circuit is increased without an increase in power consumption. The logic circuit may be implemented using CML or ECL logic.