5 volt driver in a 3 volt CMOS process
AssigneeSymbios Logic Inc.
InventorMichael J. McManus
Life of this patent
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Abstract
A CMOS voltage level shifter that is comprised of a pull-up device coupled between a first voltage supply and an node to pull up that node to the voltage of the first voltage supply. The pull-up device is responsive to a first voltage signal. A pull-down device is also included that is coupled between the node and a reference voltage supply to pull down that node to a voltage of the reference voltage. The pull-down device is responsive to second and third voltage signals. A feedback circuit is included that provides the second voltage signal to the pull-down device. A level shifted output voltage signal is provided at the node.
Claims25
A voltage level shifter comprising:
- a pull-up device coupled between a voltage supply and an node, and being responsive to a first voltage signal;
- a pull-down device coupled between the node and a reference voltage supply, and being responsive to a second voltage signal;
- and
- a feedback circuit coupled to the pull-down device and the node, wherein a level shifted voltage is provided at the node.
A CMOS voltage level shifter comprising:
- a first switch coupled between a first voltage supply and a first node;
- a second switch coupled between the first voltage supply and a second node, the first switch being responsive to a voltage at the second node and the second switch being responsive to a voltage at the first node;
- a first series of switches coupled between the first node and a reference voltage, one of the first series of switches responsive to a voltage signal;
- a second series of switches coupled between the second node and the reference voltage, one of the second series of switches being responsive to a complement of the voltage signal;
- a first pair of switches coupled to the first series of switches and coupled to receive the complement of the voltage signal;
- and
- a second pair of switches coupled to the second series of switches and coupled to receive the voltage signal,
- wherein a level shifted voltage is output from the second node.
A voltage level shifter circuit comprising:
- a first device to pull up a voltage at a first node;
- a second device to pull down a voltage at a second node;
- and
- a third device coupled to the nodes to prevent the voltage at the first node from dropping below a predetermined voltage and to prevent the voltage at the second node from exceeding a predetermined voltage.
A method of providing a level shifted voltage comprising the steps of:
- pulling up a node voltage in response to a first voltage of a voltage signal;
- pulling down the node voltage in response to a second voltage of the voltage signal;
- utilizing a body effect to prevent damaging voltage drops;
- receiving feedback voltages that correspond to the first and second voltages of the voltage signal;
- and
- generating a level shifted voltage.
A method manufacturing a level shifter comprising the steps of:
- fabricating a pull-up device couplable between a voltage supply and an node, and couplable to a first voltage signal;
- fabricating a pull-down device couplable between the node and a reference voltage supply, and couplable to a second voltage signal;
- and
- fabricating a feedback circuit couplable to the pull-down device and the node, wherein a level shifted voltage is providable at the node.
Dependencies are inferred from the claim text.