| 摘要 |
There is disclosed a current source for producing an output current the magnitude of which is controlled in a predetermined manner which comprises first and second constant current sources for supplying first and second currents, a current mirror circuit including first and second resistors through which the first and second current respectively flow, the current mirror circuit having an output to which a current amplifier is coupled and which provides the output current when rendered operative, the output current also flowing through the second resistor and switch means coupled to the first resistor which is responsive to an applied control signal for sourcing a current of predetermined magnitude to said first resistor to thereby cause excess current from said first constant current source to flow to said current amplifier to render the same operative.
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