JPH11352196A - Sampling digitizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sampling digitizer in which the number of the sampler for a high frequency signal is increased for a digitizer assembled to a system. SOLUTION: A system in which an assembled digitizer 3 exists and a sampling digitizer for a high frequency signal is extended is provided with an existent digitizer 3; and a sampling option 10 comprising a sampling head 2 inputting a high frequency signal to be measured from an input terminal and converting it to a low frequency signal, a switch 11 switching the low frequency signal from the sampling head 2 and a directly inputted low frequency signal to be measured and giving any one of the signals to the digitizer 3 and a clock generator 4 feeding a sampling clock to the sampling head 2 and an external clock signal input terminal of the existent digitizer 3. The high frequency signal and the low frequency signal can be optionally measured by providing the sampling option 10 in the former step of the existent digitizer 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sampling digitizer of one to several channels which can be added to a digitizer already incorporated in a system as a front-end option without using a dedicated sampling digitizer.

[0002]

2. Description of the Related Art For example, in an analog semiconductor test apparatus, a DU of an analog IC or an analog / digital mixed IC is used.
Digital (DUT) to test
An analog converter (hereinafter, referred to as "DAC") and a digitizer (hereinafter, referred to as "DGT") are mounted. Then, an analog signal is generated by the DAC, applied to the DUT, and the response signal is digitized by the DGT to test the analog characteristics of the DUT. Here, the DGT is an analog-to-digital converter that operates with a sampling clock.

The DGT mounted on these systems is:
There are various models depending on the purpose and application. For example, 1Ms
ps (samples / sec), but a high-precision DGT with 18-bit resolution, a high-speed DGT of 20 Msps,
There are an ultra-high-speed DGT of 00 Msps and a sampling DGT capable of measuring up to several GHz. FIG. 6 shows a block diagram of a sampling DGT or DGT mounted on a conventional system. Channels CH1, CH2 and CH3
Each is mounted as a dedicated unit. Therefore, it is necessary to add a unit according to the required number of channels.

In FIG. 6, CH1 and CH2 are sampling DGTs for high-frequency signal processing, and CH3 is a high-precision DGT. Analog measured signal is outputted from the output terminal of the DUT is input to the input terminal ₁ 1, CH2 input terminal 1 _2, CH3 input terminal 1 ₃ of the CH1. In CH1 and CH2, the sampling head 2i converts the signal into a low-frequency signal with the sampling clock from the clock generator 4i, and digitizes and processes the digitized signal with each digitizer 3i. CH3 is digitized and processed by the digitizer 3 with high precision.

[0005]

It is a very effective means to test a DUT by mounting a DGT for each application in this analog semiconductor test apparatus. However, DU
The development of analog ICs and mixed analog / digital ICs, which are T, is remarkable, the degree of integration is higher, the frequency range to be handled is wider from high frequency to low frequency, and the number of input / output pins is increasing, so it is very sophisticated Have been doing. For example, for communication LSIs and TV LSIs, LSIs having high frequencies of several hundred MHz to low frequencies of about 1 KHz for audio have been developed, and the number of input / output pins has increased and the number of pins to be tested has also increased.

Every time the DUT diversifies in this way,
Adding and installing a dedicated unit DGT or sampling DGT for testing is expensive and leads to an increase in test cost. According to the present invention, the most necessary type of DGT is mounted on the DGT, and when a high-frequency signal test is required, a sampler option can be added as a front end to perform the test, thereby reducing the test cost. The purpose is to:

[0007]

According to a first aspect of the present invention, a sampling option is provided in front of a digitizer based on a digitizer already incorporated in a system so that a signal to be measured can be reduced. When the signal to be measured is a high-frequency signal, the signal to be measured is transmitted to the digitizer through a sampling option, and the signal is measured.

The second invention is for a system which needs to test a plurality of high frequency signals. In this case, a plurality of input terminals and sampling heads are provided in parallel, and the output signals of each sampling head are converted to analog signals.
The signal was selected by the multiplexer, transmitted to the built-in digitizer, and measured. If there is a low frequency input signal, of course, the input terminal is connected directly to the analog multiplexer. Next, the configuration will be described.

The first invention is as follows. A system that has a built-in digitizer and adds a sampling digitizer for high-frequency signals.The system includes an existing digitizer, a sampling head that inputs a high-frequency signal to be measured from an input terminal and converts the signal into a low-frequency signal, and a sampling device.・ Sampling clock is supplied to the switch that switches between the low-frequency signal from the head and the low-frequency signal to be directly input and supplies one of the signals to the digitizer, and the sampling clock to the sampling head and the external clock signal input terminal of the existing digitizer. And a sampling option comprising a clock generating section, and a sampling option provided before the existing digitizer so that both high-frequency signals and low-frequency signals can be arbitrarily measured.

A second invention is as follows. This is a system in which a built-in digitizer exists and a plurality of sampling digitizers for high-frequency signals are added.The existing digitizer and a plurality of high-frequency signals to be measured are input from respective input terminals and converted into low-frequency signals. A plurality of sampling heads that output to the analog multiplexer, an analog multiplexer that selects any one of the plurality of input signals and supplies the output signal to the digitizer, a plurality of sampling heads, an analog multiplexer and an existing digitizer. A multi-sampling option consisting of a clock generator that generates and supplies each signal to an external clock signal input terminal, and a multi-sampling option in front of the existing digitizer to measure multiple high-frequency signals arbitrarily It is a sampling digitizer that can be used.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments with reference to the drawings. FIG. 1 is a block diagram of one embodiment of the present invention, FIG. 2 is a timing chart of FIG. 1, FIG. 3 is a block diagram of another embodiment of the present invention, and FIG. 4 is a timing chart of FIG. 6 are given the same reference numerals. First, FIG. 1 will be described.

The configuration shown in FIG. 1 is a system in which a digitizer 3
An option 10 is provided, and by switching the switch 11,
The high-frequency signal to be measured or the low-frequency signal to be measured before can be measured. Sampling option 10 consists of sampling head 2 and clock generator 4
And a switch 11. Measured RF signal is inputted from the input terminal 1 _2, is converted to a low frequency by the sampling head 2, is input to the digitizer 3 via the switch 11. The clock generator 4 generates and generates a sampling head clock and a digitizer clock.

FIG. 2 shows a timing chart of FIG. FIG. 2A shows an input waveform to the sampling head 2 and an output waveform a after sampling. FIG. 2 (B)
When the sampling pulse shown in (1) is given, sampling is performed at that timing. FIG. 2C shows an output waveform of the sampling head 2 converted into a low frequency, which is an input waveform of the digitizer 3. At the timing of the clock signal in FIG. 2D, the signal in FIG. 2C is digitized.

In the configuration shown in FIG. 3, a multiple sampling option 20 is provided in front of the existing digitizer 3 in order to test a plurality of high frequency signals. Multiple sampling option 20 is for multiple sampling heads 2
i (i = 1 to n) are arranged side by side, and a plurality of high frequency signals to be measured are input from a plurality of input terminals 1i. Each sampling head 2i samples each input signal with a sampling clock, converts it into a low frequency signal, and outputs it to the analog multiplexer 21. The analog multiplexer 21 selects one of the signals according to the switching signal. The selected signal under measurement is sent to the digitizer 3 and digitized. Although not shown, when a low-frequency signal to be measured exists, it can be directly supplied to the analog multiplexer 21 for selection.

The clock generator 4 has a plurality of sampling circuits.
Clock for head 2i and analog multiplexer 2
The switching signal for 1 and the timing clock for the digitizer 3 are generated and generated in synchronization with the respective timings, and supplied to the respective sections.

FIG. 4 shows a timing chart of FIG.
FIGS. 4A to 4C show a waveform of a high-frequency signal input to the plurality of sampling heads 2i and output waveforms a, b, and c which are sampled and converted to a low frequency. Sampling is performed at the timing of the sampling clock shown in FIG. Sampling head 2i
Output waveforms a, b, and c of the analog multiplexer 2
1 is selected by the switching signal shown in FIG. 4F, and the analog signal shown in FIG.
Is transmitted to The digitizer 3 digitizes with the clock signal shown in FIG. 4 (H), and the analog signals a, b,..., N which are the low frequency signals shown in FIG. 4 (G) are converted into digital data, respectively. The data is recorded in the order shown in FIG. 5 and then processed.

[0017]

As described above in detail, the present invention has a built-in digitizer 3 suitable for the system, and when a sampling digitizer is required, a sampling digitizer of a dedicated unit is added. It is possible to provide a front-end sampling option 10 that can be measured using the built-in digitizer 3 without installation. Therefore, the conventional digitizer can be measured, and the sampling digitizer can be measured for a high-frequency signal.

Further, a multiple sampling option 20 using a plurality of sampling heads 2i and an analog multiplexer 21 could be provided. Sampling head 2i for simultaneously converting a plurality of high-frequency signals to be measured into low-frequency signals using one built-in digitizer 3
It is effective that a plurality of signals to be measured can be digitized by one digitizer 3 by using.

According to the present invention, for example, in an analog semiconductor test apparatus, a special unit is additionally installed by using a sampling option 10 or a plurality of sampling options 20 even if various kinds of DUTs appear with a high speed of technological progress of a device under test. There is no need to perform this, leading to a reduction in test cost, and the effect is significant.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a timing chart illustrating the operation of FIG. FIG. 2A shows the input high-frequency signal and the output low-frequency signal a of the sampling head 2 shown in FIG.
It is a sampling clock of (A). FIG. 2C shows an input waveform of the digitizer 3, and FIG.
This is a clock signal for digitizing the waveform of (C).

FIG. 3 is a configuration diagram of another embodiment of the present invention.

FIG. 4 is a timing chart illustrating the operation of FIG. 4A to 4C show the respective high-frequency input waveforms and sample waveforms a, b, and c, and FIG. 4D shows the sampling clock. FIG. 4E shows the output waveform of the analog multiplexer, and FIG. 4F shows the switching signal of the multiplexer. FIG. 4G shows an input signal of the digitizer, and FIG. 4H shows a clock signal of the digitizer.

FIG. 5 is a digitizer for storing data measured in FIG.
FIG. 3 is a diagram of a configuration example of a memory.

FIG. 6 is a block diagram of a configuration example of each channel by a dedicated unit mounted on a conventional system.

[Explanation of symbols]

 1i (i = 1 to n) Input terminal 2, 2i (i = 1 to n) Sampling head 3 Digitizer 4, 4i Clock generator 10 Sampling option 11 Switch 20 Multiple sampling option 21 Analog multiplexer

Claims (2)

[Claims] Claims: 1. An integrated digitizer (3) is present,
In a system for adding a sampling digitizer for a high-frequency signal, an existing digitizer (3), a sampling head (2) for inputting a high-frequency signal to be measured from an input terminal and converting it to a low-frequency signal,
A switch (11) for switching between a low-frequency signal from the head (2) and a directly input low-frequency signal to be measured and supplying one of the signals to the digitizer (3); a sampling head (2) and an existing digitizer (3); And a clock generation unit (4) for supplying a sampling clock to an external clock signal input terminal of (1), and a sampling option (10) provided in front of the existing digitizer (3). A sampling digitizer characterized by being able to arbitrarily measure both high frequency signals and low frequency signals. 2. A built-in digitizer (3) is present,
In a system for adding a plurality of sampling digitizers for high-frequency signals, an existing digitizer (3) and a plurality of high-frequency signals to be measured are input to respective input terminals (1i).
A plurality of sampling heads (2) that input from the
i), an analog multiplexer (21) for selecting any one of the plurality of input signals and providing an output signal to the digitizer (3), and a plurality of sampling heads (2).
a multi-sampling option (20) comprising: i) an analog multiplexer (21); and a clock generator (4) for generating and supplying respective signals to an external clock signal input terminal of the existing digitizer (3). A sampling digitizer characterized in that a plurality of sampling options (20) are provided in front of an existing digitizer (3) so that a plurality of high-frequency signals can be arbitrarily measured.