You need to test, we're here to help.

You need to test, we're here to help.

20 November 2017

Probing Techniques and Tradeoffs (Part II)

A snapshot of available probes from Teledyne LeCroy
Figure 1: A snapshot of available probes from
Teledyne LeCroy
Our first post in this series concentrated on connectivity and various means by which one might apply an oscilloscope probe to a circuit or device under test. Now, we'll look at an "ideal" probe vs. a real-world probe, and then begin a discussion of probe specifications.

15 November 2017

Probing Techniques and Tradeoffs (Part I)

Probes are the signal's gateway to the oscilloscope
Figure 1: Probes are the signal's gateway to the oscilloscope
As any oscilloscope user (hopefully) knows, probing is perhaps the most critical element of getting good measurement results (Figure 1). We must understand our probes' specifications to ensure that we obtain the best possible signal fidelity, and thereby accurately characterize our signal under test. In this series of posts, we'll take you through probing tradeoffs and techniques and help you choose the right probe for the task at hand.

30 October 2017

The Power Integrity Measurement Mindset

Figure 1:  The holistic view
of power integrity
In kicking off a series of posts on power integrity measurements, it might be helpful to start with some thoughts on the mindset, or approach, that one should take in the endeavor. Power integrity is best approached holistically, with an eye toward each of the paths energy may take throughout a system.

24 October 2017

Automotive Ethernet Compliance: Test Equipment Requirements

The TF-ENET-B Ethernet test fixture offers all necessary interconnects for compliance test
Figure 1: The TF-ENET-B Ethernet
test fixture offers all necessary
interconnects for compliance test
Having completed an exhaustive tour of the Automotive Ethernet compliance tests, we would be remiss if we didn't offer our take on the test equipment required for the job. Let's look at what the needs would be in terms of the oscilloscope itself as well as the necessary ancillary equipment, test fixture, probes, and cables. We'll conclude with a short discussion of automated compliance software.

17 October 2017

Automotive Ethernet Compliance: Tests in Detail (Part IV)

The specified pass/fail mask for the  transmitter power spectral density test
Figure 1: The specified pass/fail mask for the
transmitter power spectral density test
We've been making our way through a detailed accounting of the compliance tests for Automotive Ethernet, and in our last post, we covered the distortion test. Now we'll wrap up the tour of the compliance test suite with the test of transmitter power spectral density.

12 October 2017

Automotive Ethernet Compliance: Tests in Detail (Part III)

This depicts the setup for the Automotive Ethernet transmitter distortion test
Figure 1: This depicts the setup for the Automotive
Ethernet transmitter distortion test
Among the compliance tests specified for Automotive Ethernet in the 100Base-T1 spec, none is more complex to set up than the test for transmitter distortion. As with the transmitter timing slave jitter test described in an earlier post, it requires access to the DUT's transmit clock (TX_TCLK).

19 September 2017

Automotive Ethernet Compliance: Tests in Detail (Part II)

Figure 1: Testing transmitter timing master jitter
entails creating a track of TIE measurements
We've begun our deep dive into the subject of Automotive Ethernet compliance testing. In our last post, we covered the first two of seven tests: maximum transmitter output droop and transmitter clock frequency. Let's now look at transmitter timing jitter in master and slave modes.