LX5249CDB数据手册Microchip中文资料规格书

描述 Description

Key Features:2.5pF Typical Disabled OutputCapacitanceFast Response, No External CapacitorsRequired5µA Supply Current In Disconnect Mode20mA Supply Current During NormalOperationLogic Command Disconnects AllTermination LinesDiffsense Line DriverCurrent Limit And Thermal ProtectionCompatible With The Pending SPI-2 LVDSpecificationPin Compatible With Industry StandardMulti-Mode TerminatorsFor UCC5240 Pin Compatible LVD ONLYTerminator (See LX5245/5246)DescriptionThe LX5248/49 IC is a Low Voltage Dif-ferential (LVD) Terminator designed to comply with the LVD termination specification in the SPI-2 document. The LX5248/49 is designed specifically for LVD applications. Because the LX5248/49 supports only LVD, it has lower output capacitance than multimode terminators such as the LX5240. The LX5248/49 Utilizes Linfinity’s UltraMAX Technology which delivers the ultimate in SCSI bus performance while saving component cost and board area. Elimination of the external capacitors also mitigates the need for a lengthy capacitor selection process. The individual high bandwidth drivers also maximize channel separation and reduces channel-to-channel noise and cross talk. The high-bandwidth UltraMAX architecture insures ULTRA-2 performance, while providing a clear migration path to ULTRA-3 and beyond. When The LX5248/49 Is Enabled, The Differential Sense (DIFFSENSE) Pin Supplies A Voltage Between 1.2V And 1.4V. In application, the terminator DIFFSENSE output is connected to the system DIFFSENSE line. If there are no single ended or HVD devices attached to the system the LVD output will be enabled. If the DIFFSENSE line is LOW, indicating a single ended device, the LX5248/49 output will be HiZ. If the DIFFSENSE line is HIGH, indicating a high voltage differential device the LX5248/49 output will be HiZ.The LX5248/49 IC Has A TTL Compatible DISCONNECT Pin. The LX5248/49 is active LOW. During sleep mode, power dissipation is reduced to a meager 5µA, while also placing all outputs in a HI Z state. Also during sleep mode, the DIFFSENSE function is disabled and is placed in a HI Z state.