High voltage PMOS level shifter
First Claim
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1. A high voltage level shifter for receiving an input voltage signal having a predetermined magnitude of voltage and for generating an output voltage signal having a different magnitude of voltage, comprising:
- a first pair of first and second field effect transistors of a first conductivity type connecting together in series between a voltage source line and a first node and having respective gate electrodes connected to a second node and respective substrates connected to said voltage source line;
a second pair of third and fourth field effect transistors of said first conductivity type connecting together in series between said voltage source line and said second node and having respective gate electrodes connected to said first node and respective substrates connected to said voltage source line;
a fifth field effect transistor of a second conductivity type connecting between said first node and a voltage reference line and having a gate electrode connected to an input terminal and a substrate connected to said voltage reference line;
an inverter having an input connected to said input terminal and an output;
a sixth field effect transistor of said second conductivity type connecting between said second node and said voltage reference line and having a gate electrode connected to said output of said inverter and a substrate connected to said voltage reference line;
an output terminal;
a third pair of seventh and eighth field effect transistors of said first conductivity type connecting together in series between said voltage source line and said output terminal and having respective gate electrodes connected to said first node and respective substrates connected to said voltage source line; and
a ninth field effect transistor of said second conductivity type connecting between said output terminal and said voltage reference line and having a gate electrode connected to said first node and a substrate connected to said voltage reference line.
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Abstract
A high voltage level shifter includes one or more complementary pairs of transistors connected together in series separate the output terminal from the input terminal so as to prevent junction breakdowns, oxide breakdowns, and punch-through breakdowns.
76 Citations
43 Claims
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1. A high voltage level shifter for receiving an input voltage signal having a predetermined magnitude of voltage and for generating an output voltage signal having a different magnitude of voltage, comprising:
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a first pair of first and second field effect transistors of a first conductivity type connecting together in series between a voltage source line and a first node and having respective gate electrodes connected to a second node and respective substrates connected to said voltage source line;
a second pair of third and fourth field effect transistors of said first conductivity type connecting together in series between said voltage source line and said second node and having respective gate electrodes connected to said first node and respective substrates connected to said voltage source line;
a fifth field effect transistor of a second conductivity type connecting between said first node and a voltage reference line and having a gate electrode connected to an input terminal and a substrate connected to said voltage reference line;
an inverter having an input connected to said input terminal and an output;
a sixth field effect transistor of said second conductivity type connecting between said second node and said voltage reference line and having a gate electrode connected to said output of said inverter and a substrate connected to said voltage reference line;
an output terminal;
a third pair of seventh and eighth field effect transistors of said first conductivity type connecting together in series between said voltage source line and said output terminal and having respective gate electrodes connected to said first node and respective substrates connected to said voltage source line; and
a ninth field effect transistor of said second conductivity type connecting between said output terminal and said voltage reference line and having a gate electrode connected to said first node and a substrate connected to said voltage reference line. - View Dependent Claims (3, 4, 5, 10, 13, 14)
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2. A high voltage level shifter for receiving an input voltage signal having a predetermined magnitude of voltage and for generating an output voltage signal having a different magnitude of voltage, comprising:
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a first pair of first and second field effect transistors of a first conductivity type connecting together in series between a voltage source line and a first node and having respective gate electrodes connected to a second node and respective substrates connected to said voltage source line;
a second pair of third and fourth field effect transistors of said first conductivity type connecting together in series between said voltage source line and said second node and having respective gate electrodes connected to said first node and respective substrates connected to said voltage source line;
a fifth field effect transistor of a second conductivity type connecting between said first node and a voltage reference line and having a gate electrode connected to an input terminal and a substrate connected to said voltage reference line;
an inverter having an input connected to said input terminal and an output;
a sixth field effect transistor of said second conductivity type connecting between said second node and said voltage reference line and having a gate electrode connected to said output of said inverter and a substrate connected to said voltage reference line;
an output terminal;
a third pair of seventh and eighth field effect transistors of said first conductivity type connecting together in series between said voltage source line and said output terminal and having respective gate electrodes connected to said second node and respective substrates connected to said voltage source line; and
a ninth field effect transistor of said second conductivity type connecting between said output terminal and said voltage reference line and having a gate electrode connected to said second node and a substrate connected to said voltage reference line. - View Dependent Claims (6, 7, 8)
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9. A high voltage level shifter for receiving an input voltage signal having a predetermined magnitude of voltage and for generating an output voltage signal having a different magnitude of voltage, comprising:
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a first pair of first and second field effect transistors of a first conductivity type connecting together in series between a voltage source line and a first node and having respective gate electrodes connected to a second node and respective substrates connected to said voltage source line;
a second pair of third and fourth field effect transistors of said first conductivity type connecting together in series between said voltage source line and said second node and having respective gate electrodes connected to said first node and respective substrates connected to said voltage source line;
a fifth field effect transistor of a second conductivity type connecting between said first node and a voltage reference line and having a gate electrode connected to an input terminal and a substrate connected to said voltage reference line;
an inverter having an input connected to said input terminal and an output;
a sixth field effect transistor of said second conductivity type connecting between said second node and said voltage reference line and having a gate electrode connected to said output of said inverter and a substrate connected to said voltage reference line; and
an output terminal, wherein said first and third transistors are depletion PMOS transistors, wherein said second and fourth transistors are enhancement PMOS transistors, and wherein said fifth and sixth transistors are intrinsic NMOS transistors. - View Dependent Claims (11, 12, 15, 36, 37, 38, 39, 40, 41, 42, 43)
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16. A high voltage PMOS level shifter for receiving an input voltage signal having a predetermined magnitude of voltage and for generating an output voltage signal having a different magnitude of voltage, comprising:
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at least two pairs of transistors for high voltage level shifting in response to said input voltage signal, wherein each of said at least two pairs has an enhancement PMOS transistor and a depletion PMOS transistor that are connected together in series; and
at least two transistors and at least one inverter for providing said input voltage signal to gates of said at least two pairs of transistors. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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31. A circuit comprising:
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a constant first voltage source approximately 16 and 20 volts, a second voltage source varying approximately between 0 volt and approximately 16 and 20 volts, a third voltage source varying approximately between 0 volt and approximately 16 and 20 volts when said second voltage source is approximately 16 and 20 volts and when said second voltage source is approximately 0 volt respectively, an enhancement PMOS transistor having a breakdown characteristic of less than approximately 17 volts; and
a depletion PMOS transistor having a breakdown characteristic of greater than approximately 17 volts, wherein said enhancement PMOS transistor and said depletion PMOS transistor are connected together in series and in between said first voltage source and said third voltage source and include respective substrates connected to said first voltage source. - View Dependent Claims (32, 33, 34)
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35. A method of protecting an enhancement PMOS transistor from high voltage breakdowns, which comprises:
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applying a first voltage selectively approximately 0 volt or approximately between 16 and 20 volts to gate electrodes of an enhancement PMOS transistor and a depletion PMOS transistor and thereby turning on both said transistors to conduct and turning off both said transistors respectively, wherein said transistors are connected together in series and in between a second voltage and a third voltage, applying said second constant voltage approximately between 16 and 20 volts, to substrates of said enhancement PMOS transistor and said depletion PMOS transistor when both said transistors are on and off and to a source of said enhancement PMOS transistor when said enhancement PMOS transistor is on and off, and applying said third voltage selectively approximately 0 volt and approximately between 16 and 20 volts when said transistors are off and on respectively, to a drain of said depletion PMOS transistor.
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Specification