SS7519 Datasheet | Silicon Standard

SS7519 Multi-mode SCSI Terminator Features !" Meets SCSI-1, SCSI-2, Ultra3 and Ultra320 Standards. !" Auto-selectable Multimode single-ended or Low Voltage Differential termination. !" Current limit and thermal shutdown protection. !" Ground driver integrated for single-ended operation !" patible with active-negation drivers. Single-Ended resistor will maintain 110Ω ± 5 % . For LVD termination, the SS7519 integrates two current sources with nine accuracy resistor strings. This architecture yields a 105Ω ±5% differential and 226Ω ±10% mon mode impedance. A fail-safe bias of 110m V is sustained when no drivers are connected to the SCSI bus. If the SS7519 detects a HVD SCSI device on the bus, all the signals will be set to a high impedance state. DESCRIPTION The SS7519 multimode SCSI terminator is both a single-ended and a low voltage differential terminator that meets the specifications of SCSI Parallel Interface (SPI-4). The SS7519 also provides backward patibility to the SCSI-1, SCSI-2 and Single-Ended specifications. The Multimode terminator contains all the functions required to terminate and auto detect for SCSI devices without hardware fluctuation. Auto-Selectable is achieved by using voltage detection on the DIFFSENSE signal. The SS7519 senses the DIFFSENSE line while sourcing the DIFFSENSE signal with LVD levels. The DIFFSENSE line being grounded indicates that one or more SE devices are attached on the bus. The SS7519 switches to the termination mode that is appropriate for the bus based on the value of the DIFFSENSE input voltage. For the Single-Ended termination, the active terminator will pull RXN to 2.85V and RXP to a hard ground. The SS7519 can sink 22m A per line as required by the SCSI specification. The Rev.2.01 6/06/2003 VRFF .Data Sheet.net/ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 TPWR TPWR R9N R9P R8N R8P HS GND R7N R7P R6N R6P DIFF_CAP DIFFSENSE M/S RIN R2P R2N HS GND R3P R3N R4P R4N R5P R5N...