UC5601N

Overview

The UC5601N is an active terminator for SCSI and SCSI-2 bus cables, providing precision resistive pull-up to a 2.9V reference across all 18 lines. It operates within a Termpwr voltage range of 4.0V to 5.25V and supports signal line voltages from 0V to +3V. The device features a typical termination impedance of 110 Ohms with ±3% accuracy due to internal trimming. In disconnect mode, supply current drops to 100–150 μA, while active operation draws 17–25 mA per open line or up to 430 mA when terminated low. The output high voltage is typically 2.9V, with a maximum sink current of -22.4 mA at 0.5V line voltage. Thermal shutdown activates at 170°C, and the component is housed in a 24-pin PDIP package.

Feature Summary

• Active termination for 18 SCSI bus lines with logic-controlled disconnect capability
• Trimmed regulator ensures accurate termination current and precise 110 Ohm impedance
• Integrated thermal shutdown and current limiting protection mechanisms

Applications

• SCSI-2 compliant bus cable segments requiring active termination
• Systems supporting hot plugging operations on SCSI interfaces
• High-speed data transmission environments utilizing single-ended drivers

Procurement Notes

Verify the specific ordering suffix against the manufacturer's latest packaging addendum to confirm pin count and physical dimensions. Ensure the selected variant matches the required thermal resistance specifications for your PCB layout. Cross-reference the RoHS status and moisture sensitivity level before finalizing procurement orders to guarantee compliance with assembly standards.

Selection Notes

Select the UC5601N when designing for standard SCSI-2 architectures requiring robust active termination. Consider the 24-pin DIP package constraints regarding board space and thermal dissipation capabilities. Evaluate the power consumption differences between active and disconnect modes to optimize system standby efficiency and heat management requirements effectively.

Part Context

This component belongs to the UC5601 family of SCSI active terminators manufactured by Texas Instruments. It succeeds earlier Unitrode designs and integrates multiple termination functions into a single monolithic IC. The N suffix specifically denotes the plastic dual-in-line package configuration, distinguishing it from SOIC or PLCC variants within the same functional family.

Replacement Considerations

UC5601DWP

FAQ

How does the UC5601 handle bus disconnection?

Upon receiving a logic command, the device disconnects all terminating resistors and turns off the internal regulator, significantly reducing standby power consumption.

What is the typical termination impedance value?

The termination impedance is internally trimmed to a typical value of 110 Ohms, ensuring compliance with SCSI cable characteristic impedance requirements.

Does the device support hot plugging?

Yes, the UC5601 meets SCSI hot plugging standards through its controlled disconnect feature and negative clamping on signal lines.