Barrier height voltage reference
AssigneeHewlett-Packard Company
InventorsMorley C. Tobey, Jr., David J. Giuliani, Peter B. Ashkin
Life of this patent
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Abstract
A barrier height voltage reference includes two field-effect transistors which are substantially identical except for their gate-to-channel potential barrier characteristics and which are biased to carry equal drain currents at equal drain voltages. The resulting difference in potential between the gate contacts of the two field effect transistors produces a voltage reference which is substantially independent of operating point, supply potential, and temperature.
Claims51
A voltage reference comprising:
- first and second field effect devices, each having a source, a drain and a gate, and each device having a different gate-to-channel potential barrier characteristic from the other;
- means coupled to the first and second field-effect devices for producing substantially identical current flow to the drains of the first and second field-effect devices;
- means coupled to the first and second field-effect devices for sensing the voltage difference between the gate-to-source voltage of the first field-effect device and the gate-to-source voltage of the second field-effect device;
- and
- means coupled to each of said field-effect devices for producing substantially identical drain-to-source voltages for said first and second field-effect devices.
A voltage reference comprising:
- first and second field-effect devices, each having a source contact, a drain contact and a gate contact and each device having a different gate-to-channel potential barrier characteristic from the other;
- means connected to the drain contacts of the first and second field-effect devices for supplying current thereto;
- means for coupling the source contacts of the first and second field-effect devices to the gate contact of the first field-effect device;
- an amplifier having a non-inverting input coupled to the source contact of the first field-effect device, an inverting input coupled to the source contact of the second field-effect device and an output coupled to the gate contact of the second field-effect device;
- and
- means for coupling to the gates of the first and second field-effect devices.
A voltage reference comprising:
- first and second voltage variable capacitors, each having a gate and a substrate and each capacitor having a different gate-to-substrate potential barrier characteristic from the other;
- means coupled to the first and second voltage variable capacitors for producing substantially the same depletion layer width in the first and second voltage variable capacitors;
- and
- means for sensing the voltage difference between the gate-to-substrate voltages produced by the first and second voltage variable capacitors.
A method for producing a reference voltage comprising the steps of:
- producing different gate-to-channel potential barrier characteristics in a plurality of field-effect devices, each field-effect device having a gate, a source and a drain;
- biasing the plurality of field-effect devices to carry substantially identical drain current flow;
- maintaining substantially similar drain to substrate potentials for said plurality of field-effect devices;
- and
- sensing the voltage difference between the gate-to-source voltages produced by a plurality of said plurality of field-effect devices.
Dependencies are inferred from the claim text.