NXP IP4772 4772 NXP4772The IP4770CZ16, IP4771CZ16, IP4772CZ16 is connected between the VGA/DVI interface and the video graphics controller and includes level shifting for the DDC signals, buffering for the SYNC lines as well as high-level ESD protection diodes for the RGB signal lines.The level shifting functions are required when the DDC controller operates at a lower supply voltage than the monitor. To use this level shifting function the gates of the two N-channel MOSFETs have to be connected to the supply rail of the DDC transceivers.Buffering for the SYNC signals is provided by two non-inverting buffers, which accept TTL input levels and convert these to CMOS compliant output levels between pins VCC(SYNC) and GND.The IP4770CZ16 and IP4771CZ16 contain the formerly external termination resistors, which are typically required for the HSYNC and VSYNC lines of the video interface:• IP4770CZ16: Rsync = 55 Ω• IP4771CZ16: Rsync = 65 Ω• IP4772CZ16: Rsync = 10 Ω to allow termination of the SYNC linesAll RGB I/Os are protected by a special diode configuration offering a low line capacitance of 4 pF (maximum) only to provide protection to downstream components for ESD voltages as high as ±8 kV contact discharge according to IEC 61000-4-2, level 4 standard.
