Patent ID: 6414516
Filing Date: 2002-07-02
Classification: H03K,H03L

Abstract:
A circuit having an operating rate that varies as a function of temperature, supply voltage and intrinsic quality of the transistors of the circuit, characterized in that it is associated to a compensation circuit comprising:a constant current source (26) supplying a substantially constant current that is independent of temperature, supply voltage, and intrinsic quality of the transistors of the circuit, a variable current source (28) supplying a current that increases with the inverse of temperature, supply voltage and intrinsic quality of the circuit transistors and means for decreasing the circuit operating rate when the difference of the currents supplied by the first and second sources increases, characterized in that said means (22, 24) are provided for decreasing the rate of variation of control signals of circuit transistors when said current difference increases, characterized in that it comprises: a first MOS transistor (14, 18) of a first conductivity type connected between a first supply terminal and an output terminal, and an inverter (16, 20) whose output terminal is connected to the gate of the first transistor, the means for reducing the rate comprising an adjustable current source connected between a second supply voltage and a supply terminal of the inverter, a second supply terminal of the inverter being connected to the first supply voltage, further characterized in that said current difference is a digital signal transported over various control lines (Idif1, . . . , Idif6), a decreasing number of which is activated for discrete increasing values of the difference, and the adjustable current source includes a group of MOS transistors (T3) of the second conductivity type connected in parallel, each of which is controlled by one of the control lines.