1. Description

LT8611SX integrates 1-to-1 DP Repeater & HD-DVI/DVI Level Shifter to simplify system level design and reduce system level cost for applications requiring single DP or HD-DVI/DVI input and single output device in personal computing system and other emerging digital appliances.

LT8611SX can be configured either as a DP source repeater or as a HD-DVI/DVI source level shifter by MODE pin. When used as a DP repeater, it repeats four lanes of low-swing AC-coupled differential input signals to a DP receiver, without level shifting, to increase transmission distance. When used as a HD-DVI/DVI level shifter (default setting), it converts four lanes of low-swing AC-coupled differential input signals to DVI and HD-DVI compliant open-drain current-mode differential output signals, up to 3 Gbit/s per lane. Each of these lanes provides a level-shifting differential buffer to translate from low-swing AC-coupled differential signaling on the source side, to TMDS-type DC-coupled differential current-mode signaling terminated into 50Ω to 3.3V on the sink side.

Equipped with receiver side equalization of up to 10dB at data rate of 3 Gb/s, LT8611SX can either extends the Displayport signal or level-shifting the dual mode Displayport signal for long distance on both sides.

The LT8611SX provides a single-ended active inverting buffer for voltage translation of the HPD signal from 5V on the sink side to 3.3V on the source side.  And, it provides a channel for level shifting of the DDC channel between 3.3V source-side and 5V sink-side. The chip also integrates a DDC buffer, defined by VESA DisplayPort Interoperability Guideline, for correct operation when connected to a dual mode DisplayPort source device.

The level shifting signal sources typically are from a display source with multi-mode I/O, which supports multiple display standards, e.g., DisplayPort, HD-DVI and DVI. These I/Os are either too far away from the connector on the board or they do not match with the display devices’ electrical specifications, for e.g. DVI V1.0 or HD-DVI V1.4b. With LT8611SX, chip set vendors are able to implement such reconfigurable I/Os on multi-mode display source devices, allowing the support of multiple display standards while keeping the number of chip set I/O pins low, or simply repeat the high-speed HD-DVI, DVI signal on the board or off the board, and give the board designers more freedom on chip placement, and signal propagation distance. Figure 3.1 is a typical application system diagram.

LT8611SX is powered from a single 3.3V power supply consuming a small amount of power and is offered in 4 types of package.

2. Features

• DisplayPort Repeating
• HD-DVI V1.4/DVI V1.0 Level Shifting
• Support HD-DVI 2.0 4:2:0 format
• DDC Level Shifting
• DDC Buffer Support
• HPD Level Shifting
• Power supply 3.3 V±10 %
• ESD protection up to 3 kV
• Power-saving modes by source-side disablement (using output enable) as well as sink-side detection (using Hot Plug Detect)
 •Transparent operation: no re-timing or software configuration required

3. Applications

• PC Motherboard / Graphics Card
• DP to HD-DVI/DVI Cable Adaptor
• Digital Set-Top-Box1-to-1
• DP Repeater