UCC561TD

Overview

The UCC561 is a low-voltage differential (LVD) regulator set designed for SCSI SPI-2, SPI-3, and SPI-4 applications. It provides integrated reference voltages and bias currents for LVD termination resistor networks, including 475Ω, 121Ω, and 475Ω configurations. The device features three regulated outputs: a 1.75-V source/sink regulator, a 0.75-V source/sink regulator, and a 1.3-V buffered output for diff sense signaling. Operating from a supply voltage of 2.7 V to 5.25 V, it incorporates thermal shutdown and active current-limiting circuitry. The component is housed in a 16-pin SOIC (DP) package.

Feature Summary

• Integrated dual sink/source regulators providing precise 1.75-V and 0.75-V references for LVD termination impedance matching.
• Dedicated 1.3-V buffered output pin specifically configured for differential sense signaling requirements.
• Built-in protection mechanisms including thermal shutdown and active current limiting to prevent damage during fault conditions.

Applications

• Servers
• Workstations
• RAID Boxes

Procurement Notes

Verify the specific ordering suffix against the manufacturer's documentation to confirm the temperature range and transport media. Ensure the selected variant matches the required operating environment specifications before procurement. Cross-reference the package designator with the intended PCB layout constraints to guarantee physical compatibility.

Selection Notes

Select this component when designing systems requiring compliant LVD termination for Ultra2, Ultra3, or Ultra320 interfaces. Verify that the application operates within the specified 2.7 V to 5.25 V supply range. Confirm that the 16-pin SOIC package fits the available board space and thermal dissipation requirements.

Part Context

This device belongs to Texas Instruments' portfolio of interface controllers and drivers. It serves as a specialized power management solution for high-speed serial data transmission standards. The component addresses the specific power delivery needs of legacy SCSI architectures requiring precise differential voltage regulation.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Evaluate alternative LVD terminator ICs based on functional equivalence of the 1.75-V, 0.75-V, and 1.3-V outputs and compatible packaging.

FAQ

Is the UCC561 suitable for SPI-5 applications?

No, the datasheet explicitly states that the UCC561 is not intended for SPI-5 applications.

What is the recommended decoupling capacitor value for the TERMPWR pin?

A minimum of 2.2 µF low-ESR capacitor is required, with a 4.7 µF low-ESR capacitor recommended for best performance.

How does the device protect against overcurrent conditions?

The UCC561 incorporates active current-limiting circuitry for both sourcing and sinking current on its regulator outputs to prevent damage.