NXP Introduces Transmission Line ESD Protection for HDMI Transmitters
NXP Semiconductors N.V. (NASDAQ: NXPI) today announced the IP4786CZ32, a highly integrated HDMI signal-conditioning IC which provides the industry’s highest levels of protection for HDMI 1.4 transmitter applications. Featuring a unique Transmission Line Clamping architecture that provides lower peak clamping voltages during an ESD strike, the IP4786 delivers strong ESD protection, the best signal integrity and the highest level of integration available in the industry today.
Designed for home entertainment systems, such as set-top boxes, standard-definition (SD) and high-definition (HD) DVD players, Blu-ray players and A/V switches, the IP4786 also features extremely low power consumption in standby mode, making it ideal for mobile applications such as portable media players, notebooks and tablets, game consoles, mobile phones, and digital camcorders and cameras.
Facts / Highlights
Highest Levels of Protection. The HDMI TMDS signals are protected by a new Transmission Line Clamping architecture that provides lower peak clamping voltages during electrostatic discharge. “Zero-clamping” buffers on the control lines completely isolate these signals from an ESD strike. All 13 signal lines are rated for ±8 kV in accordance with the IEC 61000-4-2, level 4 standard, as well as the 5-V power source pin. In addition, the IP4786CZ32 is the only solution to incorporate an overcurrent limiting 5-V LDO, conforming to the HDMI 1.4 requirement for overcurrent protection.
Best Signal Integrity. The TLC protection architecture integrates impedance-matching inductors along with the ESD protection device, providing matched 100 ohm differential impedance through the device. Unlike traditional shunt ESD devices which require board-specific external compensation, the IP4786CZ38 does not require any additional adjustment to the PCB layout, and impedance is independent of the PCB board stackup. The buffers on the control lines are the industry’s first solution that provides voltage level translation on both high and low logic levels. The buffers also enable long-cable support by overcoming the slow signal rise times associated with long cable lengths.
Clean Interface. The IP4786CZ32 was designed to provide the fewest components and smallest board footprint of any HDMI signal conditioning and protection solution. Eliminating up to 29 discrete components, the IP4786CZ32 also reduces the required footprint by 60 percent, compared with alternative integrated solutions.
The NXP IP4786CZ32 signal-conditioning IC is compatible with HDMI 1.3a and 1.4, 340-MHz pixel clock, deep color, and HDMI Ethernet and Audio return Channel (HEAC), and includes the following features:
(1)Transmission Line Clamping: impedance-matched 100-Ω differential transmission line and ESD protection for TMDS lines, with no PCB pre-compensation required
(2)Zero-clamping buffers preventing ESD pulses from passing on to the system chip’s HDMI control lines
(3)±8 kV of ESD protection for all HDMI signals, per IEC61000-4-2, level 4
(4)Current limiting LDO regulator provides 5-V output from an input voltage up to 6.5 V
(5)High and low logic level voltage translation on DDC, CEC, Hot Plug and HEAC lines compensates for high resistance in external switches in HDMI sinks
(6)Long cable support (> 700 pF/25m) through DDC buffer capacitive decoupling between system side and HDMI connector side
(7)Compact 32-pin HVQFN package (5 mm x 5 mm x 0.85 mm) with optimized routing
(8)“Clean interface” concept requiring only a single external capacitor