UCC5519PWPR

Overview

The UCC5519PWPR is a multimode SCSI terminator manufactured by Texas Instruments, designed for small computer system interface applications. It operates within a supply voltage range of 2.7 V to 5.25 V and supports SCSI-2, Ultra2 (SPI-2), Ultra3/Ultra160 (SPI-3), and Ultra320 (SPI-4) standards. The device integrates an SPI-3 mode change delay function ranging from 100 ms to 300 ms. It features a minimum source regulator current of 225 mA in single-ended mode and maintains a channel capacitance of 3 pF. The component is housed in a 28-pin TSSOP package with the PWP suffix.

Feature Summary

• Integrates automatic mode detection for SCSI-2, Ultra2, Ultra3, and Ultra320 standards via the DIFFSENSE line
• Includes built-in SPI-3 compliant delay logic to prevent bus contention during mode transitions
• Provides high-impedance state isolation when High-Voltage Differential (HVD) SCSI devices are detected on the bus

Applications

• Termination circuits for SCSI-2 and Ultra2 parallel SCSI buses
• High-speed data termination for Ultra3/Ultra160 and Ultra320 storage systems
• Multimode termination modules requiring automatic protocol adaptation

Procurement Notes

Verify that the ordering suffix 'R' confirms the taped and reeled packaging format containing 2,500 devices per reel. Confirm the specific package variant matches the required thermal pad configuration for the target PCB layout. Ensure the operating temperature range aligns with the commercial specification limits defined in the datasheet.

Selection Notes

Select this component for designs requiring compliance with multiple SCSI generations without manual switching. Verify that the board layout accommodates the 28-pin PowerPAD TSSOP package dimensions. Ensure the power supply circuitry can support the peak sink currents required during Single-Ended operation modes.

Part Context

This part belongs to the UCC5519 family of SCSI terminators produced by Texas Instruments. The PWPR designation specifically indicates the plastic TSSOP-28 package variant supplied in a tape-and-reel format. This series addresses the need for automated termination management in evolving SCSI environments.

Replacement Considerations

The datasheet notes pin compatibility with the SS-AR7519. Designers should verify electrical parameter alignment before substituting this component with other multimode SCSI terminators or legacy equivalents.

FAQ

How does the UCC5519 handle High-Voltage Differential (HVD) SCSI signals?

When HVD SCSI drivers are detected on the bus, the device disconnects all terminating resistors and enters a high-impedance state to prevent signal interference.

What is the purpose of the digital filter on the DIFFB input?

The digital filter provides a mode change delay between 100 ms and 300 ms, ensuring stable mode transitions and preventing false triggering due to noise on the bus.

Can this device operate in both Low-Voltage Differential and Single-Ended modes?

Yes, the device automatically detects the bus type via the DIFFSENSE line and configures itself for either LVD or SE operation based on the voltage levels present.