Semiconductor integrated circuit using junction field effect transistor as current control element
First Claim
1. A semiconductor integrated circuit comprising:
- DC input terminal means for receiving DC power;
common input/output terminal means for receiving DC power and for supplying power to a load;
output terminal means for supplying power to said load;
a junction field effect transistor having a first main electrode connected to said DC input terminal means and a second means electrode connected to said output terminal means;
output voltage sensing means for sensing at least a portion of a voltage between said output terminal means and said common input/output terminal means to provide a sensed output voltage;
reference voltage generating means for generating a reference voltage; and
error amplifying means for comparing said sensed output voltage and said reference voltage and for generating a control signal controlling ON/OFF operation of said junction field effect transistor on the basis of the comparison.
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Accused Products
Abstract
A semiconductor integrated circuit for obtaining constant voltage characteristics or a current switching function by controlling an output current using a current control element has a DC input terminal, a common input/output terminal, and an output terminal. A junction field effect transistor (JFET) is used as a current control element. The first main electrode (drain) and second main electrode (source) of the JFET are connected to the DC current input terminal and the output terminal, respectively. A DC power is input between the DC input terminal and the common input/output terminal. A power between the output terminal and the common input/output terminal is applied to a load. A maximum current of the JFET is limited to a drain maximum saturation current and a current having a value larger that of the maximum saturation current is not basically supplied to the JFET.
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Citations
14 Claims
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1. A semiconductor integrated circuit comprising:
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DC input terminal means for receiving DC power; common input/output terminal means for receiving DC power and for supplying power to a load; output terminal means for supplying power to said load; a junction field effect transistor having a first main electrode connected to said DC input terminal means and a second means electrode connected to said output terminal means; output voltage sensing means for sensing at least a portion of a voltage between said output terminal means and said common input/output terminal means to provide a sensed output voltage; reference voltage generating means for generating a reference voltage; and error amplifying means for comparing said sensed output voltage and said reference voltage and for generating a control signal controlling ON/OFF operation of said junction field effect transistor on the basis of the comparison. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A semiconductor integrated circuit comprising:
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DC input terminal means for receiving DC power; first output terminal means for supplying power to a first load; second output terminal means for supplying power to a second load; common input/output terminal means for receiving DC power and for supplying power to said first and second loads; a semiconductor current control element having a first electrode and a second electrode, said first electrode being connected to said DC input terminal means; a first junction field effect transistor having a first electrode connected to said second electrode of said semiconductor current control element and a second electrode connected to said first output terminal means; a second junction field effect transistor having a first electrode connected to said second electrode of said semiconductor current control element and a second electrode connected to said second output terminal means; first output voltage sensing means for sensing at least a portion of a voltage between said first output terminal means and said common input/output terminal means to provide a first sensed output voltage; second output voltage sensing means for sensing at least a portion of a voltage between said second output terminal means and said common input/output terminal means to provide a second sensed output voltage; reference voltage generating means for generating a reference voltage; first error amplifying means for comparing said first sensed output voltage to said reference voltage and for generating a first control signal controlling ON/OFF operation of said first junction field effect transistor on the basis of the comparison of said first sensed output voltage and said reference voltage; second error amplifying means for comparing said second sensed output voltage to said reference voltage and for generating a second control signal controlling ON/OFF operation of said second junction field effect transistor on the basis of the comparison of said second sensed output voltage and said reference voltage; and third error amplifying means for comparing said first and second control signals and for generating a third control signal controlling ON/OFF operation of said semiconductor current control element on the basis of said comparison of said first and second control signals. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
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Specification