Tektronix DTG5000 Series User Manual

Page 8

HDMI Compliance & Sink Characterization Using DTG5000 Series Data Timing Generator

Application Note

www.tektronix.com/signal_sources

Jitter tolerance tests require a variable amount of jitter

to be imposed on signals being sent to the device

under test. The DTG5000 Series instruments are fully

compatible with either of two recommended jitter

solutions. One solution pairs the DTG5000 Series with

an arbitrary waveform generator for either compliance

or characterization work; the other, lower-cost solution

involves a jitter generator module plugged into the

DTG5000 Series mainframe and driven by an external

function generator. Both approaches provide the

necessary modulated jitter profiles for the generated

clock signal as follows:

–

Arbitrary Waveform Generator (AWG) Method:

This solution taps the full power of the DSO and

its TDSHT3 application software, the DTG5000

Series instrument, and the AWG.

The TDSHT3 software generates the specific jitter

modulation waveform and sends it to the AWG710B,

which in turn acts as the clock source for the jitter

tolerance test. The jitter is steadily increased by the

software until the device fails. The data lines are

then verified by the oscilloscope for compliance.

The AWG has two digital “Marker” outputs that can

be used for synchronization, among other purposes.

In HDMI sink testing, one marker connects to the

DTG5000 Series external clock input while the second

marker connects to the DTG5000 Series trigger

input, both providing synchronization. Data signals

for the device under test are sourced by the

DTG5000 Series. Bias Tees are required to bring the

AWG710B out put's clock signals up to the required

TMDS levels. Conveniently, these Bias Tees can be

Series. The AWG method is able to stress the

device beyond the compliance specification levels,

making it suitable for characterization work. Figure 5

illustrates the layout of a test configuration using the

AWG method.

Figure 5.

Sink jitter tolerance test setup using an AWG as the jitter source.