Patent ID: 6046644
Filing Date: 2000-04-04
Classification: H03L

Abstract:
A phase-locked loop oscillator comprising:an oscillator circuit comprising two programmable-delay transition propagation circuits, based on cascades of logic gates with intermediate connectors and on multiplexers, with one data input, one setting input and one data output, looped by means of two D type logic flip-flop circuits with a data input D set at the logic level 1, a clock input CK, a zero-setting R input, a one-setting S input and a data output Q, each programmable-delay transition propagation circuit controlling, by its data output, the clock input CK of one of the D type logic flip-flop circuits and the zero-setting R input of the other D type logic flip-flop circuit, and each D type logic gate controlling, by its data output Q, the data input of the programmable-delay transition propagation circuit controlling its zero-setting R input and a two-input ""AND"" type logic gate interposed between the data output Q of one of the D type flip-flop circuits and the input of the programmable-delay circuit that is connected to it so as to constitute an inhibition command and oscillation activation input,two up/down counters based on combinations of logic circuits providing for the control of the setting inputs of the two programmable-delay transition propagation circuits,a divider circuit based on combinations of logic circuits connected, at the output of the oscillator circuit, to the data output Q of one of the D type logic flip-flop circuits,a phase comparator circuit based on combinations of logic circuits that receives, at input, the oscillator signal after division by the divider circuit and a phase reference signal, and detects the phase shift between these two signals, anda decision circuit, based on combinations of logic circuits, that is controlled by the phase comparator circuit and prepares the commands of the up/down counter circuits providing for the control of the setting inputs of the programmable-delay transition propagation circuits as a function of the state of phase shift detected by the phase comparator circuit.