Advanced Micro Devices, Inc.
SYMMETRICAL BALANCED C-ELEMENT

Abstract:

A C-element circuit for use in an oscillator or the like includes a first input terminal for receiving a first input signal, a second input terminal for receiving a second input signal, and an output latch for providing an output signal based on a relationship between the two input signals. A stack of input transistors is included with an outer pair of input transistors with gates connected to the first input terminal and an inner pair of input transistors with gates connected to a second input terminal. A balancing circuit operates to equalize a first delay of a change in the first input signal affecting the output signal with a second delay of a change in the second input signal affecting the output signal. Bypass control techniques are provided for using the C-element circuit with a single input.