Time Domain Reflectometry (TDR) Analysis

The Tektronix Time Domain Reflectometry (Opt. TDR) measurement solution offers a wide range of features to debug and characterize the impedance of power integrity circuits, PCBs, high-speed applications, cables, and interconnects. TDR is usually applied using specialized sampling equipment in the time domain or VNA’s looking at frequency domain data. Sampling oscilloscopes continue to be a cost-effective solution but are not as ubiquitous as real-time oscilloscopes. Tektronix offers new TDR measurement capability on versatile 4/5/6 Series B MSO real-time oscilloscopes with up to 10 GHz of acquisition bandwidth capabilities and 7.5 GHz of TDR bandwidth capabilities.
Engineers can perform TDR measurements with a simple setup including the Tektronix mixed signal oscilloscope, TDR module, and either SMA cables or TDR probe.

Key features

• Time Domain Reflectometry (Opt. TDR) on real-time 4/5/6 Series B MSOs with up to 10 GHz of acquisition bandwidth capabilities and 7.5 GHz of TDR bandwidth capabilities.
• Automatic impedance profiling using TDR signals in real time.
• Measure either single-ended or differential Z, L, C at the region of interest.
• Save results, data, and reports along with impedance traces. Recall later for offline analysis.
• Automatic one-click Preset function prepares the TDR for measurements and performs calibration for open, short and load impedances together.
• Automatic math channel setup to show impedance traces.

Key application areas for TDR

• Low cost solution for PCB coupon testing
• Verify characteristic impedance of transmission lines like cables and PCB traces
• Measure trace length, cable length, and signal delays
• Measure signal path rise/fall time and overshoot/undershoot
• Support cable and trace loss modelling
• Verify the integrity of cable crimps and connector launches
• Determine cable/PCB dielectric constants
• Measure frequency bandwidth, rise/fall time, and flatness of lab instruments and probes

TDR setup

The TDR setup requires a 4/5/6 Series B mixed signal oscilloscope and the J2154A PerfectPulse® Differential TDR from Picotest. The J2154A is a differential pulse generator. It supports either single-ended or differential TDR measurements. For performing TDR measurements on a printed circuit board, a probe is required to connect the pulse generator to the DUT.