UCC5680,pdf(9-Line LVD-Only SC

The UCC5680 is an LVD-only Small Computer System Interface (SCSI) terminator that integrates the mode change delay function required by the SPI-3 specification. The device senses what types of SCSI drivers are present on the bus via the voltage on the DIFFSENS SCSI control line. Single-ended (SE) and high-voltage differential (HVD) SCSI drivers (EIA485) are not supported. If the chip detects the presence of an SE or HVD SCSI driver, it disconnects itself by switching all terminating resistors off the bus and enters a high-impedance state. The terminator can also be commanded to disconnect the terminating resistors with the DISCNCT input. Impedance is trimmed for accuracy and maximum effectiveness. Bus lines are biased to a failsafe state to ensure signal integrity.