Agilent Technologies Inc. has introduced a de-emphasis signal converter. The Agilent N4916A enables design and test engineers to accurately and conveniently characterize gigabit speed ports and channels that operate with de-emphasized signals, which will result in more robust receiver designs with reliable operation in real PC-board environments.
The next generations of multi-gigabit devices are emerging throughout the computer, storage and communication industries. De-emphasis is a commonly used technique for transmitting electrical signals at gigabit data rates to compensate for losses caused by PC board and backplane traces.
The popular high-speed electrical standards require transmitter de-emphasis, such as PCI Express, Serial Advanced Technology Attachment (SATA) for 3 Gb/s, fully buffered DIMM, Hypertransport, Common Electrical Interface (CEI) and electrical 10 Gb Ethernet. Design and validation teams require new test tools that allow efficient and accurate characterisation and conformance testing for high-speed interfaces using de-emphasis.
When a gigabit electrical signal is transmitted over a PC board or backplane, the signal is degraded due to the electrical properties of the PC board trace. The higher the data rate, the higher the degradation. Therefore, many gigabit transmitters use a boosted pulse shape (de-emphasized signal) to compensate for the losses of the channel. Agilent's new de-emphasis signal converter allows injection of such signals when used as a front-end for Agilent's J-BERT N4903A high-performance serial BERT and the 81141/2A Serial Pulse Pattern Generator.
De-emphasis signal injection is especially needed during the design and test of high-speed devices by emulating a transmitter to analyse the channel effects under various de-emphasis and signal conditions. It is also needed for accurate characterization of receivers in a PC board environment. Here, the de-emphasis injection is needed to test the sensitivity and jitter tolerance of the receiver under ideal and worst-case signal conditions.
According to Agilent, the new Agilent N4916A de-emphasis signal converter permits devices to be tested under real-world conditions, including the channel effects caused by gigabit signal transmission over PC board traces. Custom test set-ups require more handling and tuning, which occupies engineering resources and is hard to re-produce. By providing an innovative solution for testing high-speed devices with signal de-emphasis, Agilent continues to demonstrate its leadership role in physical layer test.
The new N4916A de-emphasis signal converter offers the following benefits:
- Accurate characterisation and stress test by injecting a de-emphasized signal with variable post-cursor in 0.5 dB steps;
- Coverage of all popular and proprietary data rates up to 13.5 Gb/s;
- Convenient operation via the user interfaces of the Agilent J-BERT N4903A and 81141/2A Serial Pulse Data Generator;
- Reduced setup time as no manual adjustments are needed; and
- Worst-case testing of a device by injecting combinations of de-emphasis signals and jitter.