Stmicroelectronics (rousset) Sas

Stmicroelectronics (grenoble 2) Sas

Laurent Truphemus

Bruno Gailhard

Sebastien Ortet

Christophe Eva

Michel Cuenca

An integrated circuit includes: a primary supply stage including a primary supply node, the primary supply stage being configured to deliver a primary supply voltage to the primary supply node; a secondary supply stage including a secondary supply node, the secondary supply stage being configured to deliver a secondary supply voltage to the secondary supply node; a supply-switching circuit; a pre-charging circuit controllably coupled to the secondary supply node via the supply-switching circuit; and a volatile memory circuit controllably coupled to the primary supply node and the secondary supply node via the supply-switching circuit, wherein the switching circuit is configured to connect a supply of the volatile memory circuit either to the primary supply node in a primary supply mode, or to the secondary supply node in a secondary supply mode.

Method for precharging an integrated-circuit supply, and corresponding integrated circuit

A start-up phase of a phase lock loop (PLL) circuit includes supplying, by a phase comparator, of control pulses during which an output signal frequency of an oscillator increases. The increase includes an application of a pre-charge current at the oscillator input. A determination is made of a time variation of the output signal frequency. At least one adjustment is made of the intensity of the pre-charge current depending on the at least one determined time variation so as to approach a reference time variation.

Process for managing the start-up of a phase-locked loop, and corresponding integrated circuit

The operation of the phase-locked loop includes a startup phase where a reference signal having a duty cycle of 50% is applied to a phase comparator of the loop. A first divider of an output signal of the voltage-controlled oscillator of the loop is reset at each first type signal edge of the reference signal. The phase comparator receives the reference signal and a feedback signal from the first divider and generates a control pulse at each second type signal edge of the reference signal that causes a control voltage of the oscillator to increase.

Method for managing the startup of a phase-locked loop and corresponding integrated circuit

An operational amplifier may include a differential stage comprising two transistors whose gates are respectively linked to the two inputs of the operational amplifier. The sources of the two transistors may be linked to a first current source whose delivered current depends negatively on temperature variations and to a second current source whose delivered current is proportional to absolute temperature. The sum of these two currents may be less dependent on temperature, in that this link of the sources of the two transistors with the two current sources is effected respectively by way of two resistors, and in that the current which passes through the two transistors is imposed of proportional with temperature type, so as to allow substantially temperature-independent elimination of the offset voltage of the operational amplifier while obtaining a temperature-independent constant gain-bandwidth product.

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Pourrieres, France

Laurent Truphemus