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US 5,514,948 AGranted
Reference voltage generating circuit
AssigneeHitachi, Ltd.
InventorTakao Okazaki
Life of this patent
Estimating the term…
Abstract
A constant current is produced by a first MOSFET of depletion type whose source and gate are interconnected and then is passed through a current mirror circuit made up of MOSFETs of the opposite conduction type with respect to the first MOSFET and to a second MOSFET which has the same conduction type as the first MOSFET and whose gate and drain are interconnected. The voltage between the gate and the source of the second MOSFET is taken as an output constant voltage, which is temperature-compensated by the current ratio of the current mirror circuit.
Claims10
A reference voltage generating circuit comprising:
- a first MOSFET whose source and gate are interconnected to produce a constant current;
- a current mirror circuit made up of MOSFETs of an opposite conduction type with respect to the first MOSFET, the current mirror circuit receiving the constant current produced by the first MOSFET;
- and
- a second MOSFET having the same conduction type as the first MOSFET and having the gate and drain thereof interconnected, the second MOSFET receiving an output current from the current mirror circuit;
- wherein a voltage between the gate and the source of the second MOSFET is an output constant voltage;
- whereby the current mirror circuit temperature-compensates the output constant voltage.
3 more elements
Dependencies are inferred from the claim text.