HDMI Electrical Compliance Test Adapters

Introduction

Keysight’s D9021HDMC HDMI Tx electrical performance validation and compliance software, together with the N5991HP1A HDMI 2.1 Receiver Compliance Test Software, offers a complete test execution environment for validating and troubleshooting the electrical performance of HDMI 1.4 and HDMI 2.1 source and sink devices.

Wilder Technologies has developed a robust test point adapter (TPA) plug and receptacle product offering to enable the HDMI source/sink device or cable electrical testing.

HDMI 2.1 Application Overview

The new HDMI 2.1 specification includes a dramatically different transport system called ‘Fixed Rate Link’ (FRL). FRL uses the four high speed lanes for data transport using 16b/18b encoding and increases the maximum data rate to 12 Gbs per lane, which nearly triples the video payload. A typical HDMI 2.1 system is illustrated in Figure 1 below.

Transmitter test use case

To test a digital transmitter of any sort, the test equipment must be connected to an interface. Since physical layer test equipment uses coaxial connectors, a test point access adapter (TPA) that breaks out the test signals from the device under test with HDMI connector to the test equipment must employ a coaxial connector. Figure 2 shows a simplified illustration of how HDMI signals are accessed by the measurement system using the SP0612-60001 HDMIA2.1-TPA-P.

When not all HDMI highspeed signals can be connected to the measurement system at the same time, the D9021HDMC software will guide the user through the test process to establish a re-connection of signals when necessary. In these cases, untested lanes should be terminated properly with 3.3 V, where RT=50 ohms, using the SP0614-60001 HDMI-TPA-T.

Receiver test use case

The HDMI Receiver (N5991 Valiframe) testing supports automatic control of Keysight’s M8195A AWG (Arbitrary Waveform Generator). It calibrates the stress conditions and controls all test electronic equipment for automated receiver tolerance tests. A typical calibration setup is shown in Figure 3 whereby the TPA-P and TPA-R are used together.

The N5991 software implements the tests according to the requirements of the Compliance Test Specification for Sink Devices of HDMI version 1.4 and 2.1. It also offers some custom characterization tests to provide more details on DUT behavior beyond the limits. The final setup of a typical HDMI sink test using the N5991, with only the TPA-P connected to the DUT, is illustrated in Figure 4.