Adv Antest Corporation

Tokyo Institute of Technology

Yasuhide Kuramochi

Akira Matsuzawa

Masayuki Kawabata

Kouichiro Uekusa

Masahiro Ishida

Takahiro Yamaguchi

Kiyotaka Ichiyama

A measurement apparatus is provided that measures a current signal Ithat flows through a device under test. A transimpedance amplifier converts the current signal Iinto a voltage signal V. A digitizer converts the voltage signal Vinto digital data D. A digital signal processing unit performs signal processing on the digital data D, and controls the measurement apparatus. The measurement apparatus has a configuration comprising two separate modules, i.e., a probe module which is located in the vicinity of the device under test during a measurement, and a backend module connected to the probe module via at least one cable. The transimpedance amplifier is built into the probe module. The digitizer and the digital signal processing unit are built into the backend module.

Measurement apparatus

A measurement apparatus is provided that measures a current signal Ithat flows through a device under test. A transimpedance amplifier converts the current signal Iinto a voltage signal V. A digitizer converts the voltage signal Vinto first digital data. A digital signal processing unit performs signal processing on the first digital data, and controls the measurement apparatus. The measurement apparatus has a configuration comprising two separate modules, i.e., a probe module which is located in the vicinity of the device under test during a measurement, and a backend module connected to the probe module via at least one cable. The transimpedance amplifier is built into the probe module.

A current measurement circuit converts a current signal Iinto a voltage signal V. The current signal Iis transmitted via a signal line. A shield line is arranged in the vicinity of at least a part of the signal line. A non-inverting amplifier includes an operational amplifier, and the current signal Iis input to its non-inverting input terminal. The output signal of the non-inverting amplifier is input to its inverting input terminal as a feedback signal. An inverting amplifier amplifies the output signal of the non-inverting amplifier with inversion so as to generate a voltage signal V. An impedance circuit includes a feedback resistor Rbetween the output terminal of the inverting amplifier and the non-inverting input terminal of the operational amplifier. A guard amplifier receives the electric potential at the inverting input terminal of the operational amplifier, and applies the electric potential to the shield line.

Current measurement circuit

To decrease the burden of digital processing, provided is an AD conversion apparatus comprising a pattern generating section that, for each target bit specified one bit at a time moving downward in the output data, generates a pattern signal having a pulse width or number of pulses corresponding to a weighting of the target bit; an integrating section that integrates the pattern signals according to a judgment value for judging a value of the target bit each time a pattern signal is generated, and outputs a reference signal obtained by accumulating the integrated value of each pattern signal; a comparing section that, each time generation of a pattern signal is finished, compares the input signal to the reference signal; and an output section that outputs the output data to have values corresponding to the comparison results obtained after each generation of a pattern signal corresponding to a bit is finished.

Analog to digital converter and digital to analog converter

Provided is an output apparatus comprising a plurality of current sources; a plurality of holding sections that correspond respectively to the current sources and that each hold a designated voltage that designates a current flowing through the corresponding current source; a setting DAC that sequentially generates the designated voltage to be held by each holding section; and a supply section that sequentially switches a supply of the designated voltage generated by the setting DAC among corresponding holding sections.

Output apparatus and test apparatus

Provided is a test apparatus that tests a device under test. The device under test includes: a circuit under test; and a switching section that that connects an internal terminal being tested, from among one or more internal terminals of the circuit under test, to external terminals connected to the test apparatus. The test apparatus includes: a measuring section that controls a relay section, which provides a connection or a disconnect between two of the external terminals such that a transmission characteristic of the relay section in a connected state serves as a basis for calculating the transmission characteristic between each external terminal and each internal terminal of the circuit under test, to be in a connected state and measures the transmission characteristic of the relay section via the two external terminals; and a compensating section that compensates a signal to be supplied to the circuit under test via an external terminal and the switching section and/or a signal acquired from the circuit under test via the switching section and an external terminal, based on the measured transmission characteristic of the relay section.

Device, test apparatus and test method

Provided is a signal generating apparatus comprising a DA converter that outputs an output signal corresponding to input data supplied thereto; a sample/hold unit that is provided between the DA converter and an output end of the signal generating apparatus, and that samples an output voltage of the DA converter and holds the sampled output voltage; a comparing section that compares (i) a level of a signal output from an analog circuit that propagates the output signal to output a signal corresponding to the input data to (ii) a level of the signal output by the DA converter; and a control section that, during a holding period, (iii) provides the DA converter with comparison data instead of the input data to cause the DA converter to output a comparison voltage corresponding to the comparison data, (iv) causes the comparing section to compare a voltage of the signal output by the analog circuit to the comparison voltage, and (v) adjusts the output voltage of the DA converter based on a comparison result of the comparing section.

Signal generating apparatus and test apparatus

Provided is a signal generating apparatus comprising a DA converter that outputs an output signal corresponding to input data supplied thereto; a sample/hold unit that is provided between the DA converter and an output end of the signal generating apparatus, and that samples an output voltage of the DA converter and holds the sampled output voltage; a comparing section that compares (i) a level of a signal output from an analog circuit that propagates the output signal to output a signal corresponding to the input data to (ii) a level of the signal output by the DA converter; and a control section that, during a holding period, (iii) provides the DA converter with comparison data instead of the input data to cause the DA converter to output a comparison voltage corresponding to the comparison data, (iv) causes the comparing section to compare a voltage of the signal output by the analog circuit to the comparison voltage, and (v) adjusts the output voltage of the DA converter according to the input data based on a comparison result of the comparing section.

Provided is an AD conversion apparatus including: a differential amplifier that generates a differential input voltage according to an analog input signal; a differential DA converter of a charge redistribution type, which outputs a differential output voltage resulting from subtracting the differential input voltage from a differential comparison voltage that is in accordance with comparison data; a comparator that compares a positive output voltage and a negative output voltage in the differential output voltage; a control section that identifies the comparison data at which the differential output voltage becomes substantially 0 based on a comparison result of the comparator, and outputs the identified comparison data as output data; and a setting section that sets at least one of a common potential of the differential amplifier and a common potential of the differential DA converter, according to a targeted value of a common potential of the comparator

A-D convert apparatus and control method

There is provided a jitter measuring apparatus for measuring jitter in a signal-under-measurement, having a pulse generator for outputting a pulse signal having a pulse width set in advance corresponding to edges-under-measurement from which the timing jitter is to be measured in the signal-under-measurement, a filter for removing carrier frequency components of the signal-under-measurement from the pulse signal and a jitter calculator for calculating the jitter in the signal-under-measurement based on the signal outputted out of the filter.

Jitter measuring apparatus, jitter measuring method and test apparatus

Provided is a DA conversion apparatus comprising a capacitor array DA converter that outputs to an output line an output voltage corresponding to a digital value input thereto; and a load changing section that changes a size of a load capacitance connected to the output line. The load changing section may set gain of the DA conversion apparatus with the size of the load capacitance connected to the output line being a constant capacitance unaffected by the digital value. The load changing section may include a load capacitor connected between the output line and a standard potential; a load-side switch connected in series with the load capacitor between the output line and the standard potential; and a load capacitance control section that controls the load-side switch.

Digital-analog converting apparatus and test apparatus

Provided is a signal generating apparatus that outputs from an output end thereof an output voltage corresponding to input data supplied thereto, comprising: a DA converter that outputs a voltage corresponding to data supplied thereto; a capacitor section that is provided between the output end and a standard potential; a transmission switch that provides a connection or a disconnect between a voltage generating end of the DA converter and the output end; and a control section that causes the DA converter to charge the capacitor section with a voltage corresponding to the input data by repeatedly connecting and disconnecting the transmission switch, thereby causing the voltage of the capacitor section to gradually approach the output voltage corresponding to the input data.

Provided is an output apparatus for outputting a current from an output end, including: a plurality of current sources; a plurality of switches provided in association with the plurality of current sources respectively, and switching whether to supply a current of a corresponding current source to the output end; a time changing section that changes a propagation time of each of a plurality of control signals for controlling switching states of the plurality of switches respectively; and an adjusting section that adjusts the propagation time of each of the plurality of control signals to reduce glitch noise contained in a current supplied to the output end.

There is provided a jitter measuring apparatus for measuring jitter in a signal-under-measurement having a first pulse generator for detecting edges of the data-signal-under-measurement to output a first pulse signal having a pulse width set in advance corresponding to the edge, a second pulse generator for detecting boundaries of data sections where data values do not change in the data-signal-under-measurement to output a second pulse signal having a pulse width set in advance corresponding to timing of the detected boundaries of the data sections, a filter for removing carrier frequency components of said data-signal-under-measurement from first and second pulse signals and a jitter calculating section for calculating timing jitter in the data-signal-under-measurement based on the first and second pulse signals.

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Tokyo, Japan

Yasuhide Kuramochi