Power supply detection device
AssigneeSTMicroelectronics S.r.l.
InventorsSylvain Majcherczak, Guy Mabboux
Life of this patent
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Abstract
In an integrated circuit, a detection device detects a drop in the supply voltage of the core of the integrated circuit or an excessively slow build-up of this voltage with respect to a supply voltage of the input/output interface circuits of the integrated circuit. Outputs of the interface circuits are set to a high impedance state by the detection device to minimize their power consumption.
Claims20
A detection device for an integrated circuit comprising a core and interface circuits connected to the core for providing output signals therefrom, the detection device for detecting a level of a core supply voltage applied to the core with respect to a level of an interface supply voltage applied to the interface circuits, with the interface supply voltage being higher than the core supply voltage, the detection device comprising:
- an input stage connected to the core supply voltage and to the interface supply voltage for providing a detection signal to the interface circuits for setting outputs thereof to a high impedance state when a level of the core supply voltage is too low to enable operation of the core, said input stage comprising an inverter controlled by the core supply voltage;
- and
- a power supply stage comprising at least one diode and a capacitor connected thereto, said power supply stage being connected between the interface supply voltage and said input stage for providing the interface supply voltage thereto.
An integrated circuit comprising
- a core connected to a core supply voltage;
- at least one input/output interface circuit connected to said core, and to an interface supply voltage that is greater than the core supply voltage, said at least one input/output interface circuit comprising
- at least one level translator connected to the interface supply voltage for changing a level of a logic signal provided by said core;
- and
- a translator output stage connected to said at least one level translator;
- and
- a detection device connected to the core supply voltage and to the interface supply voltage for detecting a level of the core supply voltage with respect to a level of the interface supply voltage, said detection device for providing a detection signal to said at least one input/output interface circuit for setting outputs thereof in a high impedance state when the level of the core supply voltage is too low to enable operation of said core.
A method for operating an integrated circuit core connected to a core supply voltage, the integrated circuit also comprising at least one interface circuit connected to the core and to an interface supply voltage higher than the core supply voltage, the method comprising:
- detecting a level of the core supply voltage;
- setting an output of the at least one interface circuit to a high impedance state when the level of the core supply voltage is too low to enable operation of the core;
- the detecting and setting being performed using a detection circuit connected to the core and to the interface supply voltage, the detection circuit for providing a detection signal to the at least one interface circuit for setting the output of the at least one interface circuit to the high impedance state, the detection circuit comprising an input stage connected to the core supply voltage and to the interface supply voltage for providing the detection signal, the input stage comprising an inverter controlled by the core supply voltage, and a power supply stage comprising at least one diode and a capacitor connected thereto, the power supply stage being connected between the interface supply voltage and the input stage for providing the interface supply voltage thereto.
Dependencies are inferred from the claim text.