Current Detecting Circuit
AssigneeRohm Co., Ltd.
InventorNorio Fujii
Life of this patent
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Abstract
Indirect detection of current using a current mirror circuit is performed with good accuracy, with a small sized circuit. In a current detection circuit, a current detection current mirror circuit includes an output current transistor which supplies an output current, and a current detection transistor which supplies a detection current proportional to the output current. A compensation current mirror circuit is connected to a current supply side of the current detection current mirror circuit, so as to make a collector voltage of the output current transistor and a collector voltage of the current detection transistor equal. A current detector detects the detection current, to indirectly detect the output current.
Claims18
A current detection circuit comprising:
- a current detection current mirror circuit comprising an output current transistor which supplies an output current, and a current detection transistor which supplies a detection current proportional to the output current;
- a compensation current mirror circuit which is connected to a current supply side of the current detection current mirror circuit, so that a terminal voltage of the output current transistor and a terminal voltage of the current detection transistor have a predetermined relationship;
- and
- a current detector which indirectly detects the output current, by detecting the detection current.
Dependencies are inferred from the claim text.