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US 4,904,889 AGranted
Circuit for driving electronic devices with a low supply voltage
AssigneeSGS-Thomson Microelectronics S.A.
InventorDavide Chieli
Life of this patent
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AssigneeSGS-Thomson Microelectronics S.A.
InventorDavide Chieli
Estimating the term…
A driving circuit comprising a low-voltage power supply line, a MOS transistor having a gate terminal and a drain terminal connected to a load and a control stage connected to the power supply line and to the gate terminal of the MOS transistor. In order to allow the MOS transistor to be switched on even when the voltage of the power supply line is lower than the threshold voltage of the MOS transistor, the driving circuit comprises a bipolar transistor connected in parallel to the MOS transistor and a voltage multiplier circuit connected between a common terminal of the MOS and bipolar transistors and the control stage. The control stage comprises comparators adapted to initially switch on the bipolar transistor so as to feed the multiplier circuit, which is thus capable of generating a voltage higher than the available supply voltage, and to subsequently switch off the bipolar transistor and switch on the MOS transistor when the voltage generated by the voltage multiplier has reached at least the threshold voltage of the MOS transistor.
A circuit for driving electronic devices with a low supply voltage, comprising a first and a second reference potential lines, a first and a second electronic devices, said first and second electronic devices having first terminals connected together and to said first reference potential line, second terminals connected together and to said second reference potential line and own control terminals, a control stage connected between said first and second reference potential lines and having a first and a second control outputs connected respectively to said control terminals of said first and second electronic devices, a voltage multiplier circuit connected between said first terminals of said first and second electronic devices and said first reference potential line, said voltage multiplier circuit having a high voltage output generating an output voltage and being connected to said control stage, said control stage including means for generating a first drive signal fed to said control terminal of said second electronic device when said output voltage of said voltage multiplier circuit is lower than a threshold voltage and for generating a second drive signal fed to said control terminal of said first electronic device when said output voltage is higher than said threshold voltage.
A circuit for driving electronic devices with a low supply voltage, comprising a first reference potential line set at a first potential, a second reference potential line set at a second potential, lower than said first potential, a first electronic device having a first switching on threshold higher than said first potential, said first electronic device defining a first terminal connected to said first reference potential line, a second terminal connected to said second reference potential line and a first control terminal, a second electronic device having a second switching on threshold lower than said first potential and higher than said second potential, said second electronic device defining a third terminal connected to said first reference potential line and to said first terminal, a fourth terminal connected to said second reference potential line and said second terminal and a second control terminal, a control stage connected between said first and second reference potential lines and having a first and a second drive outputs connected respectively to said first and second control terminals of said first and second electronic devices, a voltage multiplier circuit connected between said first and second reference potential lines in series with said first and second electronic devices, said voltage multiplier circuit having a high voltage output connected to said control stage and generating an output voltage, said control stage including means for detecting said output voltage and generating a first drive signal fed to said second control terminal of said second electronic device when said output voltage is lower than said first switching on threshold and for generating a switch off signal fed to said control terminal of said second electronic device and a second drive signal fed to said first control terminal of said first electronic device when said output voltage is higher than said first switching on threshold.
A circuit for driving electronic devices with a low supply voltage, comprising a first reference potential line set at a first potential, a second reference potential line set at a second potential, lower than said first potential, a first electronic device having a first switching on threshold higher than said first potential, said first electronic device defining a first terminal connected to said first reference potential line, a second terminal connected to said second reference potential line and a first control terminal, a second electronic device having a second switching on threshold lower than said first potential and higher than said second potential, said second electronic device defining a third terminal connected to said first reference potential line and to said first terminal, a fourth terminal connected to said second reference potential line and said second terminal and a second control terminal, a control stage connected between said first and second reference potential lines and having a first and a second drive outputs connected respectively to said first and second control terminals of said first and second electronic devices, a voltage multiplier circuit having a portion connected between said first and third terminals of said first and second electronic devices and said first reference potential line, said portion having a voltage drop applied thereto, said voltage multiplier circuit having a high voltage output connected to said control stage and generating an output voltage higher than said voltage drop, said control stage including means for detecting said output voltage and generating a first drive signal fed to said second control terminal of said second electronic device when said output voltage is lower than said first switching on threshold and for generating a switch off signal fed to said second control terminal of said second electronic device and a second drive signal fed to said first control terminal of said first electronic device when said output voltage is higher than said first switching on threshold.
Dependencies are inferred from the claim text.