The UCC5638 is a multimode SCSI terminator that provides a smooth transition into LVD SCSI and automatically detects the bus type and switches termination modes.
The UCC5638 Multimode SCSI Terminator automatically selects between Single‑Ended (SE) and Low‑Voltage Differential (LVD) termination based on the DIFFB sense line, supporting SCSI‑1, SCSI‑2, Ultra2, Ultra3, Ultra160 and Ultra320 standards. It includes fail‑safe biasing, thermal packaging for low junction temperature, and a high‑impedance state for HVD devices.
The document details absolute maximum ratings, recommended operating conditions, electrical characteristics, pin functions, typical application circuits, mechanical dimensions, and packaging options. It also contains important legal notices and ordering information for the 48‑pin LQFP package.
| Operating Voltage (TRMPWR) | 2.7 V to 5.25 V |
|---|---|
| Storage Temperature | -55 °C to +150 °C |
| Package Type | 48‑pin LQFP |
| Differential Impedance | 100 Ω typical |
| Single‑Ended Impedance | 102 Ω typical |
| Supply Current (LVD SCSI Mode) | 20 mA typical |
| Differential Bias Voltage | 100 mV typical |
The device operates from 2.7 V up to 5.25 V on the TRMPWR supply pin.
It monitors the DIFFB diff‑sense line: below 0.5 V selects Single‑Ended mode, 0.7‑1.9 V selects LVD mode, and above 2.2 V indicates an HVD device, causing the terminator to shut down.
The part is supplied in an active 48‑pin LQFP (plastic quad flat‑pack) package.
The device can be stored up to +150 °C.