| 摘要 |
PURPOSE:To simplify a test, by providing the first and second current sources, which respectively supply a bias current and a pulse current, to the first and second conductors connected to the first and second terminals of a digital component and detecting the voltage of the first conductor. CONSTITUTION:At the time of operation, the bias current given by a current source 48 is set to the min. one for biasing a parasitic diode 38 in a forward direction and a large current pulse for applying forward bias to a protective diode 30 is sent out from a current source 50 and, when a conductor 62 is connected to an input 26 in a conductive state, a large current flows to an inherent resistor 52 at any time. Since a large current is sent out from the current source as mentioned above, it can be detected that the voltage between both terminals of the resistor drops at a node 64, because the resistor 52 is connected to the input 26 and an output 36 in series. Therefore, when the conductor 62 is connected to the input 26 in a conductive state and a conductor 60 is connected to the output 36 in a conductive state, voltage drop is generated in the node 64 and a simple and easy transmitting test can be performed to a semiconductor component.
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