Constant current circuit and reference voltage circuit
AssigneeSeiko Instruments Inc.
InventorsYuji Kobayashi, Takashi Imura, Masakazu Sugiura, Atsushi Igarashi
Life of this patent
Estimating the term…
Abstract
Provided is a constant current circuit and a reference voltage circuit with improved line regulation without needing a start-up circuit. The constant current circuit includes: a constant current generation circuit including NMOS transistors and a resistor; a current mirror circuit including a pair of depletion mode NMOS transistors, for allowing a current of the constant current generation circuit to flow; and a feedback circuit for maintaining constant voltages of source terminals of the pair of depletion mode NMOS transistors.
Claims6
A constant current circuit, comprising:
- a constant current generation circuit comprising NMOS transistors and a resistor;
- a current mirror circuit comprising a pair of depletion mode NMOS transistors including gate terminals connected to each other, for allowing a current of the constant current generation circuit to flow;
- and
- a feedback circuit for maintaining constant voltages of source terminals of the pair of depletion mode NMOS transistors.
Dependencies are inferred from the claim text.