DS2119M

Overview

The DS2119M is an Ultra3 LVD/SE SCSI terminator designed for multimode Low-Voltage Differential and Single-Ended termination of nine signal line pairs. It operates at a supply voltage of 5V within a temperature range of 0°C to +70°C, housed in a 28-pin TSSOP package. The device provides SE termination resistance of 110Ω (typical) with a reference voltage of 2.85V, and LVD termination with differential impedance of 110Ω and common-mode impedance of 190Ω. It features low power-down capacitance of 3pF and includes on-board thermal shutdown circuitry.

Feature Summary

• Autoselection between LVD and SE termination modes based on bus voltage sensing
• Supports actively negated SE SCSI signals with dedicated power amplifier capability
• Integrated digital filtering on the DIFFSENS line to prevent erroneous mode switching
• HVD isolation mode that disconnects termination pins when high-voltage devices are detected

Applications

• Implementation of Ultra320 and Ultra160 SCSI parallel interface systems
• Backward-compatible termination for legacy Single-Ended SCSI devices
• Multimode SCSI bus configurations requiring automatic LVD/SE adaptation

Procurement Notes

Verify component authenticity through authorized Analog Devices or Maxim Integrated distributors. Confirm RoHS compliance status via official documentation as lead-free variants carry specific ordering suffixes. Check datasheet revisions for any updates to electrical characteristics or pin definitions prior to integration.

Selection Notes

Select this component for designs requiring simultaneous support for LVD and SE SCSI protocols without external logic control. Ensure adequate decoupling capacitors are placed near TPWR and VREF pins to maintain regulation stability. Verify that the system board layout allows placement close to the SCSI connector to minimize trace length and signal reflections.

Part Context

The DS2119M belongs to the Maxim Integrated SCSI interface family, specifically engineered for high-speed data transfer standards. It serves as a critical interface element for maintaining signal integrity in complex storage area networks. The device integrates precision laser-trimmed resistor strings and current sources to ensure accurate termination across varying operating conditions.

Replacement Considerations

DS2119ME+ is the lead-free/RoHS-compliant variant of the same functional component. Both share identical electrical specifications and pinouts. Verify package availability preferences when substituting, as tape and reel options exist for automated assembly processes.