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US 6,150,844 AGranted
High voltage tolerance output stage
AssigneeSGS-Thomson Microelectronics S.A.
InventorsGiovanni Campardo, Stefano Zanardi, Carla Golla
Life of this patent
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Abstract
An output stage for electronic circuits with high voltage tolerance and of the type comprising an output buffer made up of a complementary transistor pair comprising a P-channel MOS pull-up transistor and an N-channel MOS pull-down transistor. The transistors are connected together to make up an output terminal of the stage which comprises in addition a switch having an input connected to the output terminal of the stage and an output connected to the control terminal of the pull-up transistor to drive said control terminal in a state of extinction of the output buffer.
Claims14
An output stage for an electronic circuit with a high voltage tolerance, the output stage comprising:
- an output buffer including a complementary transistor pair having a pull-up P-channel MOS transistor and a pull-down N-channel MOS transistor with the transistors being connected together to form an output stage output terminal, the pull-up P-channel MOS transistor having a control terminal;
- and
- a switch having a switch input coupled to the output stage output terminal, and a switch output coupled to the control terminal of the pull-up P-channel MOS transistor to drive the output stage into a tristate condition wherein the switch has a switching threshold voltage, Vs, such that Vcc<Vs<(Vcc+min), wherein Vcc is a supply voltage, wherein Vtp is a threshold voltage of a P-channel transistor, and wherein V.gamma. is a threshold voltage of a drain-bulk junction.
An output stage for an electronic circuit with a high voltage tolerance, the output stage comprising:
- an output buffer including a complementary transistor pair having a pull-up P-channel MOS transistor and a pull-down N-channel MOS transistor with the transistors being connected together to form an output stage output terminal, the pull-up P-channel MOS transistor having a control terminal;
- and
- a switch having a switch input coupled to the output stage output terminal, and a switch output coupled to the control terminal of the pull-up P-channel MOS transistor to drive the output stage into a tristate condition further comprising:
- an inverter;
- and
- a first P-channel MOS transistor having a control terminal connected downstream of the inverter, a source terminal connected to a reference supply voltage, and a drain terminal and a body terminal that are coupled to the control terminal of the pull-up P-channel transistor through a second P-channel MOS transistor.
3 more elements
An output stage for an electronic circuit with a high voltage tolerance, the output stage comprising:
- an output buffer including a complementary transistor pair having a pull-up P-channel MOS transistor and a pull-down N-channel MOS transistor with the transistors being connected together to form an output stage output terminal, the pull-up P-channel MOS transistor having a control terminal;
- and
- a switch having a switch input coupled to the output stage output terminal, and a switch output coupled to the control terminal of the pull-up P-channel MOS transistor to drive the output stage into a tristate condition wherein the switch includes:
- a first P-channel MOS transistor disposed between a reference supply voltage and the switch output, the first P-channel MOS transistor having a control terminal connected to the switch input;
- a second P-channel MOS transistor connected between the reference supply voltage and the switch output, the second P-channel MOS transistor having a control terminal;
- a diode configured transistor biased toward the control terminal of the second P-channel MOS transistor, the second P-channel MOS transistor being connected to the switch input through the diode configured transistor;
- and
- a pair of transistors in diode configuration and in series, the pair of transistors being connected in parallel with the diode configured transistor and biased in a direction that is opposite to that of the diode configured transistor.
5 more elements
An output stage for an electronic circuit, the output stage comprising:
- an output terminal;
- an output buffer having a pull-up transistor disposed between a first voltage supply terminal and the output terminal, and a pull-down transistor disposed between the output terminal and a second voltage supply terminal, wherein the pull-up transistor includes a control terminal;
- and
- a switch having a switch input coupled to the output terminal, and a switch output coupled to the control terminal of the pull-up transistor to control the pull-up transistor;
- wherein the first voltage supply terminal is arranged to receive a supply voltage;
- wherein the switch input is arranged to receive a switch input voltage;
- and wherein the switch is arranged to provide selectively one of the supply voltage and the switch input voltage on the switch output;
- wherein the switch is arranged to provide, on the switch output, the supply voltage when the switch input voltage is less than the supply voltage;
- and
- wherein the switch is arranged to provide, on the switch output, the switch input voltage when the switch input voltage substantially exceeds the supply voltage.
7 more elements
An output stage for an electronic circuit, the output stage comprising:
- an output terminal;
- an output buffer having a pull-up transistor disposed between a first voltage supply terminal and the output terminal, and a pull-down transistor disposed between the output terminal and a second voltage supply terminal, wherein the pull-up transistor includes a control terminal, and wherein the first voltage supply terminal is arranged to receive a supply voltage;
- and
- control means, responsive to an input voltage, for providing selectively one of the supply wherein the control means includes means for providing to the control terminal of the pull-up transistor the supply voltage when the input voltage is less than the supply voltage;
- wherein the control means includes means for providing to the control terminal of the pull-up transistor the input voltage when the input voltage substantially exceeds the supply voltage.
2 more elements
A high voltage tolerant circuit, comprising:
- a first stage having a first output and a second output;
- and
- an output stage that is driven by the first stage, the output stage including:
- an output terminal,
- an output buffer having a pull-up transistor disposed between a first voltage supply terminal and the output terminal, and a pull-down transistor disposed between the output terminal and a second voltage supply terminal, wherein the pull-up transistor includes a control terminal coupled to the first output of the first stage, and wherein the pull-down transistor includes a control terminal coupled to the second output of the first stage, and
- a switch having a switch input coupled to the output terminal, and a switch output coupled to the control terminal of the pull-up transistor to control the pull-up transistor wherein the switch has a switching threshold voltage, Vs, such that Vcc<Vs<(Vcc+min[.vertline.Vtp.vertline.,V.gamma.]), wherein Vcc is a supply voltage, wherein Vtp is a threshold voltage of a P-channel transistor, and wherein V.gamma. is a threshold voltage of a drain-bulk junction.
3 more elements
A high voltage tolerant circuit, comprising:
- a first stage having a first output and a second output;
- and
- an output stage that is driven by the first stage, the output stage including:
- an output terminal;
- an output buffer having a pull-up transistor disposed between a first voltage supply terminal and the output terminal, and a pull-down transistor disposed between the output terminal and a second voltage supply terminal, wherein the pull-up transistor includes a control terminal coupled to the first output of the first stage, wherein the pull-down transistor includes a control terminal coupled to the second output of the first stage, and wherein the first voltage supply terminal is arranged to receive a supply voltage;
- and
- control means, responsive to an input voltage, for providing selectively one of the supply voltage and the input voltage to the control terminal of the pull-up transistor;
- wherein tile control means includes means for providing to the control terminal of the pull-up transistor the supply voltage when the input voltage is less than the supply voltage;
- and
- wherein the control means includes means for providing to the control terminal of the pull-up transistor the input voltage when the input voltage substantially exceeds the supply voltage.
7 more elements
Dependencies are inferred from the claim text.