S93011A Enhanced Time Domain Analysis with TDR

Comprehensive signal integrity measurement solution for next generation high-speed digital standards

As bit rates of digital systems increase, signal integrity of interconnects drastically affects system performance. Fast and accurate analysis of interconnect performance in both time and frequency domains becomes critical to ensure reliable system performance. As managing multiple test systems becomes difficult, a single test system that can fully characterize differential high-speed digital devices is a very powerful tool.

The S93011A provides a one-box solution for high-speed interconnect analysis, including impedance, S-parameters, and eye diagrams. The S93011A is an enhancement of the S93010A time domain analysis software. The software, running on the PNA-X / PNA / PNA-L Series B-model vector network analyzers, brings three breakthroughs for signal integrity design and verification: simple and intuitive operation, fast and accurate measurements, and high ESD robustness.

Eye/Mask Mode

The S93011A provides simulated eye diagram analysis capability, eliminating the need for a pulse pattern generator. The virtual bit pattern generator is used to define a virtual bit pattern. The defined bit pattern is then convolved with the test device impulse response to create an extremely accurate measurement based eye diagram.

Simulate real-world signals through jitter insertion

One challenge with parametric characterization of interconnects, such as loss and reflections, is how to translate the results into what the eye diagram will look like at the end of a link. A more direct approach would be to measure the eye diagram. If the interconnect can correctly transmit a stressed signal, composed of the worst case compliant signal generated by the transmitter, with eye characteristics equal to or better than what is specified at the receiver, then it should operate with any combination of compliant transmitters and receivers. This precision stressed signal input can be realized with the jitter insertion feature. Impairments such as random and periodic (sinusoidal) jitter can be configured.

Determine optimal emphasis and equalization settings for your link

As data rates increase, the channel distorts the signal and can cause a partially or completely closed eye diagram that makes it impossible for the receiver to extract the data. To recover the data from the eye diagram, it must be re-opened. This is where emphasis and equalization can help. Emphasis and equalization are commonly used signal conditioning techniques when transmitting signals at gigabit data rates. The term emphasis is used to describe signal conditioning on the transmitter, while the term equalization is used on the receiver side.

Advanced Waveform Analysis Features continued

Hot TDR: impedance analysis of active devices under actual operating conditions

As bit rates of digital systems increase, impedance mismatch between components becomes a significant factor in system performance. A typical high-speed digital system consists of a transmitter, interconnect, and receiver. As the transmitter signal reaches the receiver, any impedance mismatch at the receiver will cause some of the signal to be reflected back to the transmitter. Once the reflected signal reaches the transmitter, any impedance mismatch at the transmitter will cause re-reflections. Once this re-reflected signal reaches the receiver, it will cause eye closure.

Hot TDR is the TDR and return loss measurement of active devices in the power-on state.

For Hot TDR measurements of transmitters (Tx), the Tx is powered on and outputting a data signal. The data signal from the Tx can cause measurement errors. A vector network analyzer (VNA) implements a narrowband receiver architecture, which minimizes the effect from the Tx signal. But as the VNA sweeps across the desired frequency range, there still may be frequencies where the spurious response from the Tx data signal overlaps the measurement frequency, causing measurement error. The avoid spurious feature determines the spurious frequencies from the data rate (user input) and sets the optimum frequency sweep to minimize measurement error.