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.

Automotive Ethernet Compliance: Test Equipment Requirements

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.

Automotive Ethernet Compliance: Tests in Detail (Part IV)

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.

Automotive Ethernet Compliance: Tests in Detail (Part III)

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).

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.

Automotive Ethernet Compliance: Tests in Detail (Part I)

Figure 1: Maximum transmitter output droop should not
exceed the specified maximum of 45%

We've looked in past posts at the basics of Automotive Ethernet compliance test, the five test modes, and an overview of the test setup. Now it's time to begin examining the physical-layer electrical tests in detail. As we've mentioned, there are a total of seven of these tests (six for BroadR-Reach and 100Base-T1 and one for the latter only).

Automotive Ethernet Compliance: Test Setup Overview

Figure 1: Typical test setup for Automotive Ethernet
PMA compliance test

Our last post, an overview of the five test modes for Automotive Ethernet electrical compliance testing, prepared us for a deeper look at the compliance tests themselves. But before diving into details on the differential electrical compliance tests for Automotive Ethernet, be it BroadR-Reach or 100Base-T1, it might be helpful to take a look at the setup for this endeavor.