DVI level shifter with voltage regulator

The PTN3380B is a high-speed level shifter device which converts four lanes of low-swing AC-coupled differential input signals to DVI v1.0 and HDMI v1.3a compliant open-drain current-steering differential output signals, up to 1.65 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 50 Ω to 3.3 V on the sink side. Additionally, the PTN3380B provides a single-ended active buffer for voltage translation of the HPD signal from 5 V on the sink side to 3.3 V on the source side and provides a channel for level shifting of the DDC channel (consisting of a clock and a data line) between 3.3 V source-side and 5 V sink-side. The DDC channel is implemented using pass-gate technology providing level shifting as well as disablement (isolation between source and sink) of the clock and data lines.

To provide the highest level of integration in external adapter (or: dongle) applications, PTN3380B includes an on-board 5 V DC regulator. Its output is designed to provide the required 5 V power supply to the DVI connector, thereby eliminating the need for a separate external regulator. The on-board regulator needs only two external capacitors to operate, and its output is active whenever a valid 3.3 V is applied to the PTN3380B V_DD pins.

The low-swing AC-coupled differential input signals to the PTN3380B typically come from a display source with multi-mode I/O, which supports multiple display standards, e.g., DisplayPort, HDMI and DVI. While the input differential signals are configured to carry DVI or HDMI coded data, they do not comply with the electrical requirements of the DVI v1.0 or HDMI v1.3a specification. By using PTN3380B, 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. See Figure 1.

The PTN3380B main high-speed differential lanes feature low-swing self-biasing differential inputs which are compliant to the electrical specifications of DisplayPort Standard v1.1and/or PCI Express Standard v1.1, and open-drain current-steering differential outputs compliant to DVI v1.0 and HDMI v1.3a electrical specifications. The I²C-bus channel level-translates the DDC signals between 3.3 V (source) and 5.0 V (sink).

The PTN3380B is a fully featured DVI level shifter. It is functionally comparable to PTN3360B but provides an onboard 5 V regulator.

PTN3380B is powered from a single 3.3 V power supply consuming a small amount of power (100 mW typical with no load at 5 V regulator) and is offered in a 48-terminal HVQFN48 package.