Patent Description:
In research and development applications, a measurement device such as an oscilloscope is used to perform measurements on an electric signal of a device under test, in particular for displaying electric signals such as voltages of the device under test and analyzing these signals with respect to certain properties.

The measurement device, for instance the oscilloscope, has a measuring unit that may apply at least one measurement parameter for the measurements wherein the at least one measurement parameter corresponds to a setting of the measurement unit for performing the dedicated measurement.

During the measurements, the device under test needs to be powered wherein a separately formed power source is typically used. Moreover, measurement devices are known in the state of the art that have an integrated power source, for instance a direct current source, that is configured to power the device under test during the measurements.

However, the measurement unit and the power source are separately controlled such that the measurements are performed independently of the power source, in particular its state.

Since the measurement unit and the power source are independent from each other, effects with regard to the power source cannot be taken into account during the measurements even though these effects may influence physical values of the device under test that are measured during the measurements.

<CIT> and <CIT> each show an apparatus for testing an integrated circuit wherein the power supply current forwarded to the device under test, namely the integrated circuit, is monitored.

In <CIT>, a method and an apparatus for testing a device under test are described wherein an input signal forwarded to the device under test is compared with an output signal of the device under test for testing purposes. Moreover, a voltage stabilization recognizing device which ensures that the testing of the device under test starts once the stabilization of the voltage supplied has been recognized.

Accordingly, there is a need for a measurement device that is able to provide more data that can be used for analyzing purposes.

The invention provides a measurement device according to claim <NUM>.

Further, the invention provides a method for measuring a device under test according to claim <NUM>.

The invention is based on the finding that at least one monitoring parameter of the direct current source is monitored or taken into account during the measurement wherein the at least one monitoring parameter comprises information gathered from the integrated direct current source. This additional data or information can be used for operating the measurement device during the measurements. In other words, the measurement device is enabled to observe parameters of the direct current source while measuring the device under test. Therefore, the measurement device is also configured to observe and detect events with regard to the direct current source. Generally, the measurement device can compare the measurement results obtained, in particular the physical values measured at the device under test, and the at least one monitoring parameter of the direct current source in order to obtain additional information. Accordingly, changes of the physical values measured can be compared or put in relation with (probably arising) characteristics of the direct current source while monitoring the direct current source, in particular monitoring at least one monitoring parameter. Further, the size and the installation efforts of the measurement system can be reduced as the direct current source for powering the device under test is integrated. Since the measurement unit and the direct current source are housed in a common housing being the one of the measurement device, it is possible to exchange data in an efficient manner without the need of using separate lines. The measuring unit may apply several measurement parameters simultaneously or subsequently, in particular upon selection. In general, the measuring parameters correspond to settings of the measurement device for performing the measurements on the device under test, in particular obtaining the physical values. The at least one measurement parameter may be a trigger point, a vertical deflection, an offset voltage or another suitable parameter. The additional information/data obtained can be used for analyzing errors in the device under test, in particular a printed circuit board of the device under test.

The control unit is configured to control the measurement parameter in response to the monitoring parameter. Hence, the at least one measurement parameter is controlled in response to the monitoring parameter. The measurement device controls the measurement parameter to be applied in response to the at least one monitoring parameter obtained from the direct current source. Thus, important events such as power up and power down behavior of the direct current source can be detected and taken into account for setting the measurement device appropriately, in particular its settings for measuring. Thus, the at least one measurement is controlled appropriately.

According to another aspect, the control unit is further configured to control the output of the direct current source in response to the measurements performed by the measurement unit. Thus, the output of the direct current source is controlled in response to the measurements performed. Accordingly, the measurement device is enabled to control the direct current source with regard to physical values obtained while measuring the device under test. Thus, the measurement device is configured to protect the device under test since the measurement device can shut down the direct current source powering the device under test provided that physical values have been measured that might indicate an unstable operation mode of the device under test.

Furthermore, the measurement device is configured to automatically set the optimal power for measuring the device under test, in particular wherein the power level forwarded to the device under test is controlled appropriately. Thus, the measurements are executed under optimal conditions ensuring physical values obtained/measurement results being accurate and trustworthy.

Moreover, the measurement device may control the direct current source such that a sequence of different powers, for instance <NUM> Volt, <NUM> Volt and so on, is used for powering the device under test, in particular during a (predefined) test scenario. Thus, it is no more necessary that the operator has to change the voltages applied to the device under test manually.

Particularly, the monitoring unit is a hardware circuit. Thus, the monitoring unit is realized by hardware components that may be realized on a printed circuit board.

Another aspect provides that the measurement unit is configured to be initiated to perform a measurement by the monitoring parameter. A measurement is initiated by the at least one monitoring parameter. Thus, a changing behavior of the direct current source may initiate a measurement. In general, the measurement unit is configured to initiate a measurement upon a control signal related to a monitoring parameter monitored. Further, the measurement device may be an oscilloscope such that the measuring unit is triggered by the monitoring parameter accordingly. Hence, the measurement device, namely the oscilloscope, is configured to automatically trigger on a certain monitoring parameter.

Particularly, the measurement unit is configured to be initiated to perform a measuring by monitoring the power off and/or power on of the direct current source. A measurement is initiated by the power off and/or power on of the direct current source. Accordingly, the measurement unit is configured to initiate a measurement upon a control signal related to the power off and/or power on of the direct current source. Provided that the measurement device is an oscilloscope, the measuring unit can be triggered by the power off and/or power on of the direct current source. Thus, the power status of the device under test can be viewed directly by the operator of the measurement device, in particular wherein a possible effect of the changing power status on the physical value(s) measured is shown provided that the measuring device is an oscilloscope that triggers on the monitoring parameter. Particularly, a separate channel of the oscilloscope does not have to be occupied for triggering on the power characteristics of the device under test as this is done internally. Hence, the measurements are simplified appropriately.

According to another aspect, the power consumption is a monitoring parameter. The power consumption of the direct current source is measured as a monitoring parameter wherein a measurement is initiated in response to a change in the power consumption. For instance, the current consumption is used as monitoring parameter. Thus, the power consumption of the device under test is measured within the direct current source. This monitoring parameter can be used to analyze the reason for changes of the physical values measured during the measurement of the device under test. The measurement unit may be triggered by the power consumption monitored, in particular a changing power consumption. Further, it is possible to automatically start a measurement while the power consumption of the device under test is monitored by the monitoring unit.

The control unit may be configured to switch the direct current source on or off in response to physical values measured by the measurement device at the device under test. Hence, the direct current source is switched on or off in response to physical values obtained from the device under test. This ensures that the measurement device is able to protect the device under test connected to the direct current source of the measuring device. The measurement parameters obtained may indicate an unstable operation mode of the device under test such that the measurement device controls the direct current source appropriately in order to switch off the direct current source while protecting the device under test.

The invention will now be described with reference to an exemplary embodiment of the invention which is shown in the enclosed drawings. In the drawings,.

In <FIG>, a measurement device <NUM> is shown that is used for measuring a device under test <NUM>. In the shown embodiment, the measurement device <NUM> is an oscilloscope.

The measurement device <NUM> has a housing <NUM> which encompasses a measurement unit <NUM> being allocated to inputs <NUM>, <NUM>, a monitoring unit <NUM>, a control unit <NUM> and an integrated direct current source <NUM>. The integrated direct current source <NUM> has two outputs <NUM>, <NUM> for powering the device under test <NUM> to be measured.

Further, the measurement device <NUM> has a display <NUM> that is used for displaying data obtained by a processing unit <NUM> of the measurement device <NUM>. In the shown embodiment, the processing unit <NUM> and the control unit <NUM> are formed as a single unit.

The measurement unit <NUM> is configured to perform measurements on an electric signal of the device under test <NUM> wherein the electric signal is fed to the measurement device <NUM> via the inputs <NUM>, <NUM>. For this purpose, the measurement unit <NUM> is configured to apply at least one measurement parameter such as a trigger point, a vertical deflection, an offset voltage or another suitable parameter used by the oscilloscope for analyzing the electric signal. Accordingly, the at least one measurement parameter applied corresponds to a setting of the measurement device <NUM> while performing the measurements on the device under test <NUM>. The measurement unit <NUM> may apply more than one measurement parameter simultaneously.

The monitoring unit <NUM> is configured to monitor at least one monitoring parameter of the direct current source <NUM> during the measurements, for instance a power status of the direct current source <NUM> or the power consumption of the device under test <NUM> being powered by the direct current source <NUM>. As the direct current source <NUM> is configured to power the device under test <NUM>, the at least one monitoring parameter obtained can be used in conjunction with the physical values measured from the device under test <NUM>, for instance for comparison purposes. Thus, the monitoring parameter and the physical values can be analyzed or put in relation with each other for analyzing purposes.

Both, the measurement unit <NUM> as well as the monitoring unit <NUM>, are connected to the control unit <NUM> such that the measurement parameter(s) as well as the monitoring parameter(s) are taken into account during the measurements of the electric signal.

Furthermore, the control unit <NUM> is configured to control the measurement unit <NUM>, in particular the measurement parameter(s) applied, as well as the direct current source <NUM>, in particular the output of the direct current source <NUM> such as the power status.

In addition, the control unit <NUM> is configured to control the measurement unit <NUM>, in particular the measurement parameter(s) applied, in response to the monitoring parameter(s) obtained by the monitoring unit <NUM>. Particularly, the control unit <NUM> is configured to control the output of the direct current source <NUM> in response to the physical values obtained during the measurements performed by the measurement unit <NUM>.

The monitoring unit <NUM> may be established by a hardware circuit being integrated in the measurement device <NUM>.

In general, the measurement device <NUM> and the device under test <NUM> provide a measurement system <NUM>.

The different data obtained while measuring the electric signal of the device under test <NUM> will be described with reference to the flow-chart shown in <FIG> representing a method for measuring the device under test <NUM>.

The measurement device <NUM> performs measurements on the device under test <NUM> that is powered by the integrated direct current source <NUM> during the measurements.

As already mentioned, the monitoring unit <NUM> monitors at least one monitoring parameter of the direct current source <NUM> such as the power consumption of the device under test <NUM>, in particular changes of the power consumption, or the status of the direct current source <NUM>.

Further, the measuring unit <NUM> applies at least one measuring parameter for performing the measurements on the device under test <NUM> such as a trigger point, a vertical deflection, an offset voltage or another suitable parameter. The measurement parameter is applied to the signal(s) fed to the measurement device <NUM> via the inputs <NUM>, <NUM> that is/are processed by the measuring unit <NUM>.

In addition, the measurement device <NUM> is configured to obtain physical values from the device under test <NUM> during the measurements, in particular from the signals fed to the measurement device <NUM> via the inputs <NUM>, <NUM>. These physical values represent the measurement results.

All these variables are forwarded to the control unit <NUM> that is configured to control the measurement unit <NUM> and the direct current source <NUM> appropriately, in particular in response to the monitoring parameters and the physical values obtained, respectively.

For instance, the control unit <NUM> may control the output of the direct current source <NUM> in response to the physical values obtained from the device under test <NUM>. Thus, the powering of the device under test <NUM> can be controlled. This ensures that the measurement device <NUM> can protect the device under test <NUM> during the measurements if the control unit <NUM> detects a critical operation mode of the device under test <NUM>. The control unit <NUM> may detect this critical operation mode by analyzing the physical values obtained during the measurements.

Generally, the control unit <NUM> is configured to control the output of the direct current source <NUM> in response to measurements performed by the measurement unit <NUM>.

Furthermore, the measurement device <NUM>, in particular the control unit <NUM>, automatically sets the optimal power for measuring the device under test <NUM> by setting the integrated direct current source <NUM> appropriately. Hence, the power level of the power forwarded to the device under test <NUM> is controlled appropriately ensuring that the device under test <NUM> is powered in an optimized manner with regard to the measurement performed by the measurement device <NUM>, in particular the measurement unit <NUM>.

Moreover, the measurement device <NUM> can control the direct current source <NUM> such that a sequence of different powers is used for powering the device under test <NUM> during a certain test scenario. For instance, a voltage of <NUM> Volt is applied for a certain time that is raised to <NUM> Volt for a certain time and so on. Thus, it is no longer necessary that the operator of the measurement device <NUM> has to change the voltages applied to the device under test <NUM> manually. A test scenario can be performed in an automatic manner.

Furthermore, the control unit <NUM> is also configured to switch off the direct current source <NUM> in response to the physical values obtained in order to protect the device under test <NUM>. Accordingly, the device under test <NUM> is protected by the measurement device <NUM> as a over-current or any other critical operating state can be prevented.

In addition, the control unit <NUM> controls the measurement unit <NUM> in response to the at least one monitoring parameter that is provided by the monitoring unit <NUM>, in particular adjusting the at least one measurement parameter in response to the monitoring parameter. For instance, the at least one monitoring parameter may be a power-off or power-on status of the direct current source <NUM>.

Thus, the control unit <NUM> may initiate a measurement to be performed by the measurement unit <NUM>. For instance, the control unit <NUM> triggers the measurement unit <NUM> of the measurement device <NUM> being an oscilloscope. Accordingly, a certain measurement on the device under test <NUM> is performed once a changing status of the direct current source <NUM> has been detected. Particularly, the physical values obtained by the device under test <NUM> are output around the trigger event, in particular displayed.

Thus, the control unit <NUM> is configured to trigger the measurement unit <NUM> in order to start measurements on the device under test <NUM> once a changing power consumption has been detected by the control unit <NUM> in cooperation with the monitoring unit <NUM>.

Triggering on the at least one monitoring parameter, in particular a changing power consumption, ensures that the reason for the changing characteristics of the device under test <NUM> can be verified, in particular the changing power consumption. The changing power consumption corresponds to a power up or a power down of the device under test <NUM> during the measurements.

Moreover, a power status of the direct current source <NUM> may be taken into account such as the power off and/or the power on of the direct current source <NUM>. The measurement unit <NUM> may be triggered on that monitoring parameter(s) such that a measurement is initiated. The characteristics of the device under test <NUM> can be directly observed during the power on and/or power off state while triggering on this monitoring parameter.

Claim 1:
A measurement device (<NUM>) comprising:
an integrated direct current source (<NUM>) configured to power a device under test (<NUM>);
a monitoring unit (<NUM>) configured to monitor at least one monitoring parameter of the direct current source (<NUM>); characterized in that
the measurement device (<NUM>) is an oscilloscope, wherein the measurement device (<NUM>) has a housing (<NUM>) which encompasses a measurement unit (<NUM>) being allocated to inputs (<NUM>, <NUM>), the monitoring unit (<NUM>), a control unit (<NUM>), and
the integrated direct current source (<NUM>),
wherein the measurement unit (<NUM>) is configured to perform measurements on an electric signal of the device under test (<NUM>) while applying at least one measurement parameter for performing the measurements, wherein the electric signal is fed to the measurement device (<NUM>) via the inputs (<NUM>, <NUM>), wherein the at least one measurement parameter applied corresponds to a setting of the measurement device (<NUM>) while performing the measurements on the device under test (<NUM>); and wherein
the control unit (<NUM>) is configured to control the at least one measurement parameter in response to the at least one monitoring parameter.