UCC5680PW24

Overview

The UCC5680PW24 is a low-voltage differential (LVD) Small Computer System Interface (SCSI) terminator manufactured by Texas Instruments. It operates within a supply voltage range of 2.7 V to 5.25 V and supports an operating temperature range of 0°C to 70°C. The device is housed in a 24-pin Thin Shrink Small-Outline Package (TSSOP). In LVD mode, it provides a differential impedance of 105 Ω and a common-mode impedance of 150 Ω. The component includes built-in SPI-3 mode change delay functionality ranging from 100 ms to 300 ms.

Feature Summary

• Integrates mode change delay function required by the SPI-3 specification
• Senses SCSI driver types via DIFFSENS line and disconnects if SE or HVD drivers are detected
• Provides differential failsafe bias to ensure signal integrity on bus lines
• Includes thermal shutdown protection with hysteresis

Applications

• Terminating Low-Voltage Differential (LVD) SCSI buses
• SPI-3 compliant system implementations
• Ultra2, Ultra3/Ultra160, and Ultra320 SCSI interface termination

Procurement Notes

Verify the specific package variant against design requirements, as the UCC5680 family includes both 24-pin and 28-pin options. Confirm that the application environment strictly utilizes LVD drivers, as the device does not support Single-Ended or High-Voltage Differential modes. Ensure proper decoupling capacitors are placed near the TRMPWR and REG pins to maintain stability.

Selection Notes

Select this component for designs requiring automatic detection and termination of LVD SCSI buses. Note that three ICs are required at each end of the bus to terminate all 27 lines. Verify that the board layout adheres to strict capacitance balancing rules for differential pairs, as the device performance relies on precise trace impedance matching.

Part Context

This part belongs to the UCC5680 series of SCSI terminators. The 'PW' suffix indicates the TSSOP package type, while '24' specifies the 24-pin configuration. A 28-pin version (UCC5680PW28) is also available, which includes an additional LVD status output pin not present in the 24-pin variant.

Replacement Considerations

The UCC5680PW24G4 is a lead-free and RoHS-compliant equivalent of the standard UCC5680PW24. Designers should verify pin compatibility and electrical specifications when substituting between these variants.