UCC5628FQPTR

Overview

The UCC5628FQPTR is a multimode SCSI terminator manufactured by Texas Instruments, designed for single-ended (SE) and low-voltage differential (LVD) parallel interfaces. It operates within a supply voltage range of 2.7 V to 5.25 V and supports temperatures from 0°C to 70°C. The device provides 14 termination lines with an LVD differential impedance of 100 Ω to 110 Ω and an SE impedance of 102.3 Ω to 117.7 Ω. In LVD mode, the typical supply current is 25 mA, while SE mode draws up to 10 mA. It features integrated regulators providing 1.25 V, 1.3 V, and 2.7 V outputs. Packaged in a 48-pin LQFP (PT), this specific suffix indicates a tape-and-reel quantity of 1000 units.

Feature Summary

• Automatically detects bus type via DIFFB pin and switches between single-ended and LVD modes
• Provides differential failsafe biasing to ensure signal integrity during mode transitions
• Includes thermal packaging with heatsink ground pins to reduce junction temperature
• Outputs status bits indicating active termination mode

Applications

• SCSI-1, SCSI-2, and SCSI-3 bus architectures
• Ultra (Fast-20) and Ultra2 (SPI-2 LVD) parallel interface systems
• Ultra3 (SPI-3) and Ultra320 (SPI-4) high-speed data transfer environments

Procurement Notes

Verify that the component matches the UCC5628FQPTR designation to confirm the 48-pin LQFP package and 1000-unit reel quantity. Ensure the operating environment remains within the specified 0°C to 70°C temperature range. Confirm that the system power supply adheres to the 2.7 V to 5.25 V limits to maintain proper regulator functionality and termination accuracy.

Selection Notes

Select this device for applications requiring automatic transition between SE and LVD terminations without manual configuration. It is suitable for mixed-mode buses where different device types may be connected. Ensure the PCB layout accommodates the 48-pin LQFP footprint and utilizes the heatsink ground pins for effective thermal management. Verify compatibility with the required SPI standards supported by the internal diff sense logic.

Part Context

This part belongs to the UCC5628 family of multimode SCSI terminators. The FQP suffix denotes the standard 48-pin LQFP package for commercial temperature ranges, while the TR suffix specifies the tape-and-reel packaging format. This variant is functionally identical to the tube-packaged UCC5628FQP but optimized for automated surface-mount assembly processes.

Replacement Considerations

UCC5628FQPG4 and UCC5628FQPTRG4 are lead-free versions of this component. These variants offer identical electrical characteristics and pinouts, differing only in compliance with RoHS directives regarding lead content.

FAQ

How does the UCC5628 handle High Voltage Differential (HVD) devices?

If the device detects an HVD SCSI device on the bus, it automatically switches to a high-impedance state to prevent interference.

What is the purpose of the DISCNCT pin?

The DISCNCT pin shuts down the terminator when it is not located at the end of the bus. A low signal on this pin enables the terminator operation.

How is the bus mode detected?

Mode detection is performed via the DIFFSENS line. A voltage below 0.5 V indicates Single Ended mode, between 0.7 V and 1.9 V indicates LVD mode, and above 2.4 V indicates HVD mode.