
Maxim Integrated
GENERAL DESCRIPTION
The DS2120 Ultra3 LVD SCSI terminator is a low-voltage differential (LVD) terminator. If the device is connected in an LVD-only bus, the DS2120 uses LVD termination. If any single-ended (SE) or highvoltage differential (HVD) devices are connected to the bus, the DS2120 disconnects from the bus. This is accomplished inside the part automatically by sensing the voltage on the SCSI bus DIFFSENS line.
For the LVD termination, the DS2120 integrates two current sources with nine precision resistor strings. Three DS2120 terminators are needed for a wide SCSI bus.
FEATURES
■ Fully Compliant with Ultra3, Ultra160, Ultra320, and Ultra2 (LVD only) SCSI
■ Provides Low-Voltage Differential (LVD) Termination for Nine Signal Line Pairs
■ Zero Temperature Coefficient Termination Resistors
■ Autoselection of LVD Termination
■ 5% Tolerance on LVD Termination Resistance
■ Low Power-Down Capacitance of 3pF
■ Built-In Mode Change Filter/Delay
■ On-Board Thermal Shutdown Circuitry
■ SCSI Bus Hot Plug Compatible
APPLICATIONS
Raid Systems
SCSI Host Bus Adapter Cards (HBA)
Servers
SCSI Cables
Network Attached Storage (NAS)
Storage Area Networks (SANs)