Abstract: A voltage regulating device includes a comparison circuit for comparing a voltage proportional to an output voltage to a fixed reference voltage. The fixed reference voltage is received on a first input and the voltage proportional to an output voltage is received on a second input. The voltage regulating device further includes a variable resistance-forming circuit controlled by the output of the comparison circuit and disposed so that the output voltage remains substantially constant. The voltage regulating device may be supplied with a variable input voltage. The voltage regulating device further includes a second comparison circuit so that the output voltage remains substantially constant if the input voltage is greater than a threshold, and substantially equal to the input voltage if the input voltage is less than the threshold.

Abstract: A voltage regulator includes a regulation MOS transistor and an amplifier providing an output for driving a gate of the regulation MOS transistor. The amplifier drives the gate based upon a difference between a reference voltage and a feedback voltage. The voltage regulator may further include a circuit for making the amplifier switch to a standby mode with low current consumption when the difference between the supply voltage and the output voltage of the regulator is below a first threshold. This is done while maintaining, at the gate of the regulation transistor, a voltage that keeps the regulation transistor on. The present invention is particularly applicable to the management of power supplies in portable telephones.

Abstract: A linear regulator of the type including a power MOS transistor of a first channel type, controlled by an amplifier having an output stage including, between two supply terminals, a resistor and a first MOS control transistor of a second channel type. The regulator further includes a start-up circuit having a switchable resistor in parallel on said first resistor.

Abstract: A voltage regulating device includes a comparison circuit for comparing a voltage proportional to an output voltage to a fixed reference voltage. The fixed reference voltage is received on a first input and the voltage proportional to an output voltage is received on a second input. The voltage regulating device further includes a variable resistance-forming circuit controlled by the output of the comparison circuit and disposed so that the output voltage remains substantially constant. The voltage regulating device may be supplied with a variable input voltage. The voltage regulating device further includes a second comparison circuit so that the output voltage remains substantially constant if the input voltage is greater than a threshold, and substantially equal to the input voltage if the input voltage is less than the threshold.

Abstract: A voltage regulator includes a regulation MOS transistor with low serial resistance having a first terminal connected to a voltage source and a second terminal connected to the output of the voltage regulator and an amplifier having an output driving a gate of the transistor. The gate is driven based upon a difference between a reference voltage and a feedback voltage. The regulator may also include an anti-overshoot switch with a first terminal connected to the gate of the regulation MOS transistor and a second terminal is taken to a potential for turning the regulation MOS transistor off. A switch controller closes the switch when the output voltage of the regulator is higher than a first threshold. The first threshold may be higher than the nominal value of the output voltage.

Abstract: A voltage regulator includes a regulation MOS transistor with low serial resistance having a first terminal connected to a voltage source and a second terminal connected to the output of the voltage regulator and an amplifier having an output driving a gate of the transistor. The gate is driven based upon a difference between a reference voltage and a feedback voltage. The regulator may also include an anti-overshoot switch with a first terminal connected to the gate of the regulation MOS transistor and a second terminal is taken to a potential for turning the regulation MOS transistor off. A switch controller closes the switch when the output voltage of the regulator is higher than a first threshold. The first threshold may be higher than the nominal value of the output voltage.

Abstract: A voltage regulator includes a regulation MOS transistor and an amplifier providing an output for driving a gate of the regulation MOS transistor. The amplifier drives the gate based upon a difference between a reference voltage and a feedback voltage. The voltage regulator may further include a circuit for making the amplifier switch to a standby mode with low current consumption when the difference between the supply voltage and the output voltage of the regulator is below a first threshold. This is done while maintaining, at the gate of the regulation transistor, a voltage that keeps the regulation transistor on. The present invention is particularly applicable to the management of power supplies in portable telephones.