Comparator capable of preventing large noise voltage
First Claim
1. A comparator having first and second voltage input terminals and a voltage output terminal, for comparing a first input voltage from said first voltage input terminal and a second input voltage from said second voltage input terminal to produce and supply an output voltage to said voltage output terminal, said comparator comprising:
- a first current mirror circuit having a first current input terminal and a first current output terminal;
a first field-effect transistor having a first drain electrode connected to said first current input terminal, a first source electrode connected to a first power terminal, and a first gate electrode connected to said first voltage input terminal, said first power terminal supplied with a low voltage having a low level;
a second field-effect transistor having a second drain electrode connected to said first current output terminal, a second source electrode connected to said first power terminal, and a second gate electrode connected to said second voltage input terminal; and
a second current mirror circuit having a second current input terminal connected to said first current output terminal and a second current output terminal connected to a second power terminal through a resistor and to said voltage output terminal, said second power terminal supplied with a high voltage having a high level which is higher than said low level.
1 Assignment
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Accused Products
Abstract
A first field effect transistor has a drain electrode connected to a first current input terminal of a first current mirror circuit and a gate electrode connected to a first voltage input terminal which is supplied with a first voltage input terminal. A second field effect transistor has a drain electrode connected to a first current output terminal of the first current mirror circuit and a gate electrode connected to a second voltage input terminal which is supplied with a second input voltage. A second current mirror circuit has a second current input terminal connected to the first current output terminal and a second current output terminal connected to a power terminal through a resistor and to a voltage output terminal which is supplied with an output voltage. A comparator may include third and fourth current mirror circuits instead of the first and the second field effect transistors. In this event, the third current mirror circuit has a third current input terminal supplied with a first input current and a third current output terminal connected to the first current input terminal. The fourth current mirror circuit has a fourth current input terminal supplied with a second input current and a fourth current output terminal connected to the first current output terminal.
42 Citations
18 Claims
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1. A comparator having first and second voltage input terminals and a voltage output terminal, for comparing a first input voltage from said first voltage input terminal and a second input voltage from said second voltage input terminal to produce and supply an output voltage to said voltage output terminal, said comparator comprising:
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a first current mirror circuit having a first current input terminal and a first current output terminal; a first field-effect transistor having a first drain electrode connected to said first current input terminal, a first source electrode connected to a first power terminal, and a first gate electrode connected to said first voltage input terminal, said first power terminal supplied with a low voltage having a low level; a second field-effect transistor having a second drain electrode connected to said first current output terminal, a second source electrode connected to said first power terminal, and a second gate electrode connected to said second voltage input terminal; and a second current mirror circuit having a second current input terminal connected to said first current output terminal and a second current output terminal connected to a second power terminal through a resistor and to said voltage output terminal, said second power terminal supplied with a high voltage having a high level which is higher than said low level. - View Dependent Claims (3, 4, 5, 6, 7, 8)
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2. A comparator having first and second current input terminals and a voltage output terminal, for comparing a first input current from said first current input terminal and a second input current from said second current input terminal to produce and supply an output voltage to said voltage output terminal, said comparator comprising:
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a first current mirror circuit having a first current output terminal and said first current input terminal; a second current mirror circuit having a second current output terminal and said second current input terminal; a third current mirror circuit having a third current input terminal connected to said first current output terminal and a third current output terminal connected to said second current output terminal; and a fourth current mirror circuit having a fourth current input terminal connected to said third current output terminal and to said second current output terminal and a fourth current output terminal connected to a power terminal through a resistor and to said voltage output terminal, said power terminal supplied with a power voltage. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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Specification