CCVGA7C5中文资料VGA PORT COMPANION CIRCUIT数据手册UTC规格书

描述 Description

The UTC  CCVGA7C5 is an ESD solution for the VGA port connector. This device integrates ESD protection for all signals, Two non-inverting drivers provide buffering for the HSYNC and VSYNC signals from the video controller IC. These buffers accept TTL input levels and convert them to CMOS output levels that swing between Ground and VCC。 These drivers have a nominal 60Ω output impedance to match the characteristicimpedance of the HSYNC and VSYNC lines of the video cablestypically used. The inputs of  these drivers also have high impedance pull−ups (50kΩ nom.) pulling up to the VAUX rail.   In addition, the DDC_CLOCK and DDC_DATA channels have 1.8kΩ resistors pulling these inputs up to the main 5V (VCC) rail. The upper ESD diodes for the R, G and B channels are connected to a separate supply rail (VRGB) to facilitate interfacing to graphics controller ICs with low voltage supplies. The remaining channels are connected to the main 5 V rail (VCC). The lower diodes for the R, G and B channels are also connected to a dedicated ground pin (GNDA) to minimize crosstalk due to common ground impedance. ESD protection is implemented with current steering diodes designed to safely handle the high peak surge currents associated with the IEC−1000−4−2 Level−4 ESD Protection Standard (±8kV contact discharge). When the channels are subjected to an electrostatic discharge, the ESD current pulse is diverted via the protection diodes into the positive supply rails or ground where they may be safely dissipated.

特性 Features

7 Channels of ESD Protection Designed to Meet IEC−1000−4−2 Level−4 ESD Requirements (±8kV Contact Discharge) Three Independent Supply Pins (VCC, VRGB and VAUX) to Facilitate Operation with Sub−Micron Graphics Controller ICs Very Low Loading Capacitance from ESD Protection Diodes at Less than 5pF Typical   TTL to CMOS Level−Translating Buffers for the HSYNC and VSYNC Lines High impedance Pull−Ups (50kΩ Nominal to VAUX) for HSYNC and VSYNC Inputs Pull−Up Resistors (1.8kΩ Nominal to VCC) for DDC_CLK and DDC_DATA Lines