| 摘要 |
PROBLEM TO BE SOLVED: To provide a voltage-applied current measuring apparatus realizable by a cheaper circuit arrangement and a semiconductor tester using the same. SOLUTION: The current-measuring apparatus has a floating type current measuring unit 300, having a floating form insulated from a circuit ground GND. The unit 300 is mainly composed of a floating power source, a current detecting resistance, a gain-regulating resistance, an operational amplifier(OPAMP), an DC converter, a series output unit and a photocoupler. The floating power source intended to feed circuits used for the measuring unit 300 with DC powers is an insulated DC power source floating from the circuit ground and is composed of, e.g., light-emitting elements and solar cells.
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