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US 6,147,521 AGranted
Detector of range of supply voltage in an integrated circuit
AssigneeSGS-Thomson Microelectronics S.A.
InventorsHubert Degoirat, Mathieu Lisart
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AssigneeSGS-Thomson Microelectronics S.A.
InventorsHubert Degoirat, Mathieu Lisart
Estimating the term…
The disclosure relates to detectors of the level of supply voltage in an integrated circuit. The disclosed detector is designed to detect the crossing of low levels of supply voltage. It comprises a first arm to define a first reference voltage and a second arm to define a second reference voltage, these two reference voltages varying differently as a function of the supply voltage and their curves of variation intersecting for a value of the supply voltage located close to a desired threshold. A comparator receives the two reference voltages. The first arm has a resistive divider bridge, an intermediate connector of which constitutes the first reference voltage. The second arm comprises a resistor series-connected with a native P type MOS transistor, the point of junction of this resistor and this transistor constituting the second reference voltage. A non-linear element may be parallel-connected to the resistor which constitutes the first reference voltage.
A detector of the level of supply voltage Vcc of an integrated circuit, comprising a first arm to define a first reference voltage and a second arm to define a second reference voltage, these two reference voltages varying differently as a function of a supply voltage and their curves of variation intersecting for a value of the supply voltage close to a desired threshold, and a comparator receiving the two reference voltages, wherein the first arm has a resistive divider bridge, of which an intermediate connector constitutes the first reference voltage and the second arm comprises a resistor series-connected with a native P type MOS transistor, the point of junction of this resistor and this transistor constituting the second reference voltage, the native transistor in the arm that defines the second reference voltage, in combination with the resistive divider bridge in the arm that defines the first reference voltage, provides high stability of the threshold value of supply voltage Vcc that is to be detected, the resistive divider bridge, providing very efficient control, by a simple choice of relative values of resistance, of the zone of intersection of the curves of the first and second reference voltages as a function of a supply voltage Vcc.
A detector of the level of supply voltage Vcc of an integrated circuit, comprising a first arm to define a first reference voltage and a second arm to define a second reference voltage, these two reference voltages varying differently as a function of a supply voltage and their curves of variation intersecting for a value of the supply voltage close to a desired threshold, and a comparator receiving the two reference voltages, wherein the first arm has a resistive divider bridge, of which an intermediate connector constitutes the first reference voltage and the second arm comprises a resistor series-connected with a native P type MOS transistor the point of junction of this resistor and this transistor constituting the second reference voltage, wherein a non-linear element with relatively low conduction threshold voltage, is parallel-connected to a resistor of the divider bridge.
A detector of the level of supply voltage Vcc of an integrated circuit. comprising a first arm to define a first reference voltage and a second arm to define a second reference voltage, these two reference voltages varying differently as a function of a supply voltage and their curves of variation intersecting for a value of the supply voltage close to a desired threshold, and a comparator receiving the two reference voltages, wherein the first arm has a resistive divider bridge, of which an intermediate connector constitutes the first reference voltage and the second arm comprises a resistor series-connected with a native P type MOS transistor, the point of junction of this resistor and this transistor constituting the second reference voltage, wherein the resistive divider bridge comprises a bridge resistor having means to short-circuit the bridge resistor as a function of the output of the comparator, in order to introduce a hysteresis in the level detection threshold.
Dependencies are inferred from the claim text.