Abstract: A test system measures parameters of a device under test (DUT), including a transistor. The test system includes a first voltage source unit for supplying a gate voltage; a second voltage source unit for supplying one of a drain voltage or a source voltage, the second voltage source having a current measurement device for detecting one of a drain current or a source current flowing through the transistor, respectively; a feedback unit for outputting a feedback current, based on the one of the drain or source currents; and an error amplifier for outputting a feedback control signal, based on comparison of the feedback current and a target current value. The first voltage source unit adjusts the gate voltage based on the feedback control signal so that the one of the drain or source currents converges to match the target current value.

Abstract: The apparatus includes a frame to accommodate more than two instrumentation modules; a multiplexed bus associated with the frame and including more than two connectors; and a sense instrumentation module and a source instrumentation module mounted in the frame, electrically connected to respective ones of the connectors, and collectively including a communication link, and a circuit path that includes, in series between a sense input and a source output, a sense circuit to generate a sense output signal representing a sensed parameter dependent on a source signal; a feedback controller to generate a control signal in response to the sense output signal; and a source circuit to generate the source signal in response to the control signal. The communication link is in the circuit path, and includes a bus transmitter and a bus receiver each configured to select a channel of the multiplexed bus via which to communicate.

Abstract: A test system measures parameters of a device under test (DUT), including a transistor. The test system includes a first voltage source unit for supplying a gate voltage; a second voltage source unit for supplying one of a drain voltage or a source voltage, the second voltage source having a current measurement device for detecting one of a drain current or a source current flowing through the transistor, respectively; a feedback unit for outputting a feedback current, based on the one of the drain or source currents; and an error amplifier for outputting a feedback control signal, based on comparison of the feedback current and a target current value. The first voltage source unit adjusts the gate voltage based on the feedback control signal so that the one of the drain or source currents converges to match the target current value.

Abstract: The apparatus includes a frame to accommodate more than two instrumentation modules; a multiplexed bus associated with the frame and including more than two connectors; and a sense instrumentation module and a source instrumentation module mounted in the frame, electrically connected to respective ones of the connectors, and collectively including a communication link, and a circuit path that includes, in series between a sense input and a source output, a sense circuit to generate a sense output signal representing a sensed parameter dependent on a source signal; a feedback controller to generate a control signal in response to the sense output signal; and a source circuit to generate the source signal in response to the control signal. The communication link is in the circuit path, and includes a bus transmitter and a bus receiver each configured to select a channel of the multiplexed bus via which to communicate.

Abstract: A phase controlling apparatus is disclosed. The phase controlling apparatus controls phases of signals which are output from a plurality of signal sources corresponding to first phase information which indicates a phase of a predetermined signal. The phase controlling apparatus includes a phase information storing section and a phase controlling section. The phase information storing section stores second phase information which indicates a phase of a signal which is output from each of the plurality of signal sources. The phase controlling section changes a phase of a signal which is output from at least one of the plurality of signal sources corresponding to the second phase information stored in the phase information storing means to control the difference of phases of signals which are output from the plurality of signal sources.

Abstract: A phase controlling apparatus is disclosed. The phase controlling apparatus controls phases of signals which are output from a plurality of signal sources corresponding to first phase information which indicates a phase of a predetermined signal. The phase controlling apparatus includes a phase information storing section and a phase controlling section. The phase information storing section stores second phase information which indicates a phase of a signal which is output from each of the plurality of signal sources. The phase controlling section changes a phase of a signal which is output from at least one of the plurality of signal sources corresponding to the second phase information stored in the phase information storing means to control the difference of phases of signals which are output from the plurality of signal sources.

Abstract: The switching matrix apparatus is provided with a plurality of relay switches for opening and closing the electrical connections between a plurality of input terminals and a plurality of output terminals, and a display unit in which a plurality of light-emitting portions are arranged in a matrix in correspondence with the respective relay switches and in which indicators indicating the positions of the light-emitting portions in at least multiple columns and rows are displayed along at least two sides of the light-emitting portions arranged in a matrix. In order to facilitate confirmation of the position of a light-emitting portion that is about to be selected or has been selected with a light pen on the display unit, light is emitted by at least one other light-emitting portion relating to the light-emitting portion that is about to be selected or has been selected.

Abstract: As an anti-slip mechanism for a light pen whose tip is pressed against a light-emitting portion of the LED display unit to detect the position, a plurality of anti-slip members are arranged, above the light-emitting portions, at a surface panel of the LED display unit. The mechanism facilitates the positioning of the light pen to an intended light-emitting portion.