UCC5680PW24TR

Overview

The UCC5680PW24TR 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 provides 105 Ω differential impedance and 150 Ω common-mode impedance in LVD mode, with a typical differential bias voltage of 125 mV. It features a built-in SPI-3 mode change delay filter ranging from 100 ms to 300 ms. The component detects bus driver types via the DIFFSENS line and disconnects if single-ended or high-voltage differential drivers are present. It is housed in a 24-pin TSSOP package.

Feature Summary

• Integrates automatic SCSI bus termination with support for multiple standards including SPI-2, SPI-3, SPI-4, Ultra2, Ultra3/Ultra160, and Ultra320.
• Detects connected driver types via the DIFFSENS control line and automatically disconnects terminating resistors upon detecting incompatible single-ended or high-voltage differential drivers.
• Includes a built-in mode change delay and filter function compliant with SPI-3 specifications to prevent false mode transitions due to noise.
• Maintains bus lines in a failsafe state through impedance trimming and biasing when disconnected or in standby modes.

Applications

• Termination networks for Low-Voltage Differential (LVD) SCSI buses
• SPI-3 compliant system implementations requiring mode change delays
• Multi-standard SCSI environments supporting Ultra2, Ultra3, and Ultra320 protocols

Procurement Notes

Verify the specific ordering suffix 'TR' indicates tape and reel packaging containing 2,000 units per reel. Confirm the '24' designation corresponds to the 24-pin TSSOP package variant rather than the 28-pin version. Ensure the component status is listed as Active for new designs. Check for RoHS compliance and lead finish specifications such as CU NIPDAU in the latest manufacturer documentation before finalizing orders.

Selection Notes

Select this component specifically for LVD-only SCSI applications where automatic detection of incompatible SE or HVD drivers is required. Ensure the design accommodates the 100 ms to 300 ms mode change delay inherent to the device. Verify that the board layout adheres to strict capacitance limits defined for Ultra320 speeds. Consider using three devices per bus end to terminate all data and control lines effectively.

Part Context

The UCC5680 series serves as a specialized terminator for SCSI interfaces, addressing the transition from High-Voltage Differential (HVD) to Low-Voltage Differential (LVD) signaling. The PW24 variant specifically offers a 24-pin form factor suitable for compact PCB layouts. It complements other SCSI interface components by handling the complex termination requirements mandated by evolving SCSI standards like SPI-3.

Replacement Considerations

The UCC5680PW24G4 is a lead-free equivalent of the standard UCC5680PW24. Designers should verify pin compatibility and electrical characteristics remain identical between the G4 and non-G4 variants before substitution.