CM2009数据手册电路保护的TVS-混合技术规格书PDF

描述 Description

The CM2009 connects between a video graphics controller embedded in a PC, graphics adapter card or set top box and the VGA or DVI-I port connector. The CM2009 incorporates ESD protection for all signals, level shifting for the DDC signals and buffering for the SYNC signals. ESD protection for the video, DDC and SYNC lines is implemented with low-capacitance current steering diodes. All ESD diodes are designed to safely handle the high current spikes specified by IEC-61000-4-2 Level 4 (±8KV contact discharge if CBYP is present, ±4KV if not). The ESD protection for the DDC signal pins are designed to prevent ''back current'' when the device is powered down while connected to a monitor that is powered up. Separate positive supply rails are provided for the VIDEO, DDC and SYNC channels to facilitate interfacing with low voltage video controller ICs to provide design flexibility in multi-supply-voltage environments. Two non-inverting drivers provide buffering for the HSYNC and VSYNC signals from the video controller IC (SYNC1,SYNC2). These buffers accept TTL input levels and convert them to CMOS output levels that swing between Ground and VCC_SYNC, which is typically 5V. Additionally, each driver has a series termination resistor (RT) connected to the SYNC_OUT pin, eliminating the external termination resistors typically required for the HSYNC and VSYNC lines of the video cable. There are three versions with different values of RT to allow termination at typically 65Ω (CM2009-00) or 15Ω (CM2009-02). The 15Ω(CM2009-02) version will typically require two external resistors which can be chosen to exactly match the characteristic impedance of the SYNC lines of the video cable. Two N-channel MOSFETs provide the level shifting function required when the DDC controller is operated at a lower supply voltage than the monitor. The gate terminals for these MOSFETS (VCC_DDC) should be connected to the supply rail

特性 Features

Includes ESD protection, level-shifting, buffering and sync impedance matching
7 channels of ESD protection for all VGA port connector pins meeting IEC-61000-4-2 Level 4 ESD requirements (±8kV contact discharge)
Very low loading capacitance from ESD protection diodes on VIDEO lines, 4pF maximum
Bi-directional level shifting N-channel FETs provided for DDC_CLK & DDC_DATA channels
5V drivers for HSYNC and VSYNC lines

应用 Application

VGA and DVI-I ports
Digital TV, Set Top Box, PC/Notebook, Gaming

简介

CM2009属于电路保护的TVS-混合技术。由制造生产的CM2009TVS - 混合技术混合技术 TVS（瞬态电压抑制器）产品族中的产品属于过压保护产品，其中结合了基于多种技术的保护机制，例如串联连接的 MOV（金属氧化物压敏电阻）和 GDT（气体放电管），旨在同时获得低漏电流和自恢复箝位工作特性。