IMP offers three Multimode SCSI Terminators designed to support the Ultra2 Low Voltage Differential (LVD) data transmission mode developed by the T-10 standards group. Multimode devices provide backward compatibility to SCSI-1, 2, 3 and Ultra peripherals.

Click here for Single Ended SCSI Terminators

  The IMP5241/5242 differ only in their LOW/HIGH disconnect polarity. The IMP5241CDB is pin compatible to the Dallas Semiconductor DS2118ME and the Unitrode UCC5630MWP.

Package options include the 24-pin TSSOP (CPW) and 36-pin SSOP (CDB).
Part No.
28 TSSOP 9-Line ULTRA3 LVD/SE SCSI Terminator
9-Line Multimode LVD/SE SCSI Terminator
9-Line Multimode LVD/SE SCSI Terminator
28 TSSOP 9-Line Multimode LVD/SE SCSI Terminator
24 TSSOP LVD SCSI Terminator
24 TSSOP LVD SCSI Terminator
Application Note AN-3: Multimode SCSI Terminators and LVD Signaling
  All IMP multimode devices feature auto-selectable LVD or SE (single-ended) termination, high-speed response without external capacitors and a high bandwidth driver that reduces channel-to-channel noise and crosstalk.
    External Capacitors Eliminated  
  External components are minimized. In the LVD mode, a fast buffer instead of regulators that require external capacitors supplies the common mode voltage. In SE mode, the nonlinear adaptive terminator eliminates external capacitors and more closely matches the loaded SCSI bus impedance. No external capacitors are required for references or regulators on the IMP multimode devices. Only a termpower bypass capacitor is required.

In addition, other IC terminators require an external RC delay network to accommodate the100mS delay it takes between changes on the DIFFSENSE line and changes on their outputs. The IMP multimode parts include an internal digital counter that eliminates the external RC network.
    Master/Slave Operation  
  Driving the Master/Slave pin LOW disables the on-board DIFFSENS reference, allowing the use of an external master reference. If the Master/Slave pin is allowed to float or is driven HIGH, the internal DIFFSENSE reference is active.
    Automatic Mode Selection  
  Proper mode selection is automatic. If DIFFSENSE is below 0.5V single-ended operation is selected and if between 0.7V and 1.9V LVD operation is selected. Outputs are placed in a high-impedance state when DIFFSENSE is above 2.4V.

A sleep or disable mode reduces supply current to 10 microamperes maximum and puts the DIFFSENSE and outputs in a high impedance state.