LX5243CPW数据手册Microchip中文资料规格书

描述 Description

Key Features:
• Auto-Selectable LVD or Single-EndedTermination
• 3.0pF Maximum Disabled OutputCapacitance
• Fast Response, No ExternalCapacitors Required
• Compatible with Active NegationDrivers
• 15µA Supply Current inDisconnect Mode
• Logic Command Disconnects AllTermination Lines
• Diffsense Line Driver
• Ground Driver Integrated forSingle-Ended Operation
• Current Limit and ThermalProtection
• Hot-Swap Compatible (Single-Ended)
• Ultra160 compliant
• See LX5245/5246 for LVDTermination Only
• Pin Compatible With DS2119and UCC5630The LX5241/42/43 is a multimode SCSI terminator that is compatible with to the SCSI SPI02 (Ultra2 SCSI), SCSI SPI-3 (Ultra3 SCSI or Ultra160 SCSI), and pending SCSI SPI-4 (Ultra320) specifications developed by the T10 standards committee for low voltage differential (LVD) termination, while providing backwards compatibility to the SCSI, SCSI-2, and SPI single-ended specifications. Multimode compatibility permits the use of legacy devices on the bus without hardware alterations. Automatic mode selection is achieved through voltage detection on the Diffsense line. The LX5241/42/43 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 reduce channel to channel noise and cross talk. The high bandwidth architecture insures ULTRA2 performance while providing a clear migration path to ULTRA3 and beyond. When the LX5241/42/43 is enabled, the differential sense (DIFFSENSE) pin supplies a voltage between 1.2V and 1.4V. In application this pin is tied to the DIFFSENSE input of the corresponding LVD transceivers. This action enables the LVD transceiver function. DIFFSENSE is capable of supplying a maximum of 15mA. Tying the DIFFSENSE pin high places the LX5241/42/43 in a HI Z state indicating the presence of an HVD device. Tying the pin low places the part in a single-ended mode while also signaling the multimode transceiver to operate in a single-ended mode.Recognizing the needs of portable and configurable peripherals, the LX5241/42/43 have a TTL compatible sleep/disable mode. During this sleep/disable mode, power dissipation reduced to a meager 15uA while also placing all outputs in a HI Z state. Also during sleep/disable mode, the DIFFSENSE function is disabled and placed in a HI Z state.Another key feature of the LX5241/42/43 is the master / slave function. Driving this pin high or floating the pin enables the 1.3V DIFFSENSE reference. Driving the pin low disables the on board DIFFSENSE reference and enables use of an external master reference device.  ROHS