Invented by Frederick E. Warren, Harvey B. Crisler, Robert G. Jacobson, Chang H. Kim, Edward C. Llewellyn, Zehntel Inc

In-circuit testing (ICT) is a critical process in the electronics manufacturing industry. It involves testing the electrical connections and components of a printed circuit board (PCB) while it is still in production. This process helps to identify any faults or defects in the PCB before it is assembled into a final product. The market for in-circuit testing systems has been growing steadily over the years, driven by the increasing demand for high-quality electronics products. The global market for in-circuit testing systems is expected to grow at a CAGR of 4.5% from 2020 to 2025, according to a report by MarketsandMarkets. The report also states that the market size is expected to reach USD 1.3 billion by 2025, up from USD 1.0 billion in 2020. The growth in the market can be attributed to several factors, including the increasing demand for consumer electronics products, the growing complexity of PCBs, and the need for high-speed testing. One of the key drivers of the market is the increasing demand for consumer electronics products. With the rise of the Internet of Things (IoT) and smart devices, the demand for electronics products has been growing rapidly. This has led to an increase in the production of PCBs, which in turn has driven the demand for in-circuit testing systems. These systems help to ensure that the PCBs are of high quality and free from defects, which is essential for the reliability and performance of the final product. Another factor driving the market is the growing complexity of PCBs. As electronics products become more advanced, the PCBs that power them become more complex. This complexity makes it harder to detect faults and defects in the PCBs, which is where in-circuit testing systems come in. These systems are designed to test the PCBs at a very high speed and with a high degree of accuracy, making it easier to detect any issues. Finally, the need for high-speed testing is also driving the market for in-circuit testing systems. With the increasing demand for electronics products, manufacturers need to produce PCBs at a faster rate than ever before. This means that testing needs to be done quickly and efficiently, without compromising on quality. In-circuit testing systems are designed to test PCBs at a very high speed, making them an essential tool for electronics manufacturers. In conclusion, the market for in-circuit testing systems is growing steadily, driven by the increasing demand for high-quality electronics products, the growing complexity of PCBs, and the need for high-speed testing. As the electronics industry continues to evolve, the demand for these systems is only set to increase, making it an exciting time for the in-circuit testing market.

The Zehntel Inc invention works as follows

An incircuit testing system that can stimulate the device-under test at any desired electric node. It also records the device’s response waveform at each node. The response waveform can be edited and used to reset the device during a subsequent incircuit test.

Background for In-circuit testing system

1. “1.

This invention is related to digital incircuit testers. This invention is a user-interactive system that generates testing waveforms and measures the outputs of devices to whom those waveforms are applied. In-circuit refers to a device or circuit that is not required to be isolated from surrounding circuits to apply test signals or monitor its output.

2. “2.

U.S. Pat. No. No. 4,216,539 is incorporated by reference and assigned to the applicant of the present application. It discloses an incircuit digital tester. This patent describes a digital tester signal generator that can generate a variety of digital signals to test components of the circuit under test. U.S. Pat. No. No. 4,339 819 is incorporated by reference and assigned to the applicant of the present application. It discloses a programmable sequencing generator for in-circuit electronic testing. This patent describes a circuit that generates data bus signals and control input test signals for testing bus-oriented electrical components such as microprocessors in a circuit under examination.

Some companies make in-circuit testers that can display CRT waveforms generated by a device under-test (DUT). Genrad’s Genrad 2270 series, manufactured in Concord, Mass. is an example of such a device. The device can’t record or edit the DUT’s output waveforms, however. Some companies make logic analyzer workstations that can be used to debug microprocessors. These workstations use personal computers. Northwest Instrument Systems, Inc., Beaverton, Ore, produces one such workstation.

The current workstations are plagued by numerous deficiencies. Existing workstations are unable to provide stimuli at the circuit board’s middle. These workstations are also unable to “incircuit back drive”. These workstations cannot edit DUT output waveforms or use edited waveforms in subsequent tests. A user interface is not provided for personal computers that are used by workstations.

There is a need for a computer workstation that can not only view measured waveforms but also record and edit those waveforms. Then, those edited waveforms can be used as stimuli to retesting the DUT.

The invention addresses the drawbacks of prior art by providing an apparatus and method for in-circuit test that can edit the measured waveforms from the DUT, and which can stimulate the DUT using the edited measured waves. The undesirable feature common to existing devices wherein the user is not able to program a test from the DUT measured waveforms is eliminated by the invention, and it is believed to be the first personal-computer-based test system which can achieve using edited DUT-measured waveforms as stimuli to the same DUT.

Under another aspect of the invention, a DUT’s microprocessor is able to “free run”, executing onboard programs (the board self test in ROM), for example. The present invention measures DUT signals using an external clock or a clock within the test system. A qualifying signal is also used to create a measurement clock valid for the bus cycles of particular microprocessors.

When viewed in conjunction with the drawings, the detailed description of preferred embodiments will make the above-mentioned and other aspects more obvious.

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