HDMI / DisplayPort Signal Booster (Control Links)
ESD protection, level shifting and drive for the AUX / DDC and HPD lines of a DisplayPort or HDMI source.
What is it?
Besides the high-speed video lanes, every DisplayPort and HDMI link has slow control lines: the DisplayPort AUX channel or the HDMI DDC (I²C) bus, plus hot-plug detect (HPD). The source chip often runs these at low I/O voltages (down to 1.0 V), while the connector side runs at the higher DP or HDMI supply, must survive ESD and, for HDMI, must drive the capacitance of a long cable. A control-link booster sits between the chip and the connector: it protects the lines, shifts the voltage level, blocks backdrive current when the source is off, and adds a dynamic pull-up so DDC edges stay fast on long cables. It does not touch the video lanes.
When do you need it?
- DisplayPort or HDMI source ports on graphics cards, notebooks, game consoles and set-top boxes.
- Dual-mode ports where one DisplayPort connector carries either DP AUX or HDMI DDC, selected through the CONFIG1 pin.
- A GPU or SoC with low-voltage I/O (down to 1.0 V) that cannot connect straight to the connector-side supply.
- HDMI sources that must keep DDC timing compliant with long cables (up to 700 pF of cable capacitance).
How to pick the right one
- Standard and mode
- Check the DisplayPort / HDMI versions it supports and, for a dual-mode port, that it handles both AUX and DDC.
- Voltage levels
- The connector-side supply range and the lowest ASIC I/O voltage it can shift down to.
- DDC drive
- For HDMI, a dynamic (boosted) pull-up keeps the I²C rise time under 1 μs with the full cable plus sink load (up to 750 pF).
- Backdrive protection
- When the source is powered off, a powered sink must not feed current back into it through DDC, HPD or the supply pin.
- ESD rating
- IEC 61000-4-2 level 4 (8 kV contact, 15 kV air) on the connector-side pins.
- Package
- A small QFN placed next to the connector.
What Magnias offers
MIDPHD5-N22: ESD protection and signal booster for the control links of DisplayPort 2.0 and HDMI 2.1 sources. It handles DP AUX (AC coupled) or HDMI DDC (bidirectional, with dynamic pull-up and clock-stretching support), selected by the SELECT pin, and manages HPD. It shifts a 1.62-5.3 V connector-side supply (VREF2) down to ASIC levels as low as 1.0 V (VREF1), blocks backdrive current, and gives 8 kV contact / 15 kV air ESD protection on the connector side. QFN2.0x2.0-12L, -30 to 85 °C. It does not re-drive the video lanes; protect those with Magnias low-capacitance ESD diodes.