Hitachi HUS103036FL3800 Low voltage differential LVD mode, Drawing No. Sheet No. Revision, 19/43

5.2 Low voltage differential (LVD) mode

The NW and NC drives have two different transceivers to allow customer to use it in traditional systems which may use single-ended drivers and receivers, or to use it in low voltage differential (LVD) systems which use LVD drivers and receivers.

Their I/O circuits are selectable using the I/O "DIFFSENS" line. When the I/O "DIFFSENS" line is between -0.35V and +0.5V, the drive interface circuits operate single-ended. When "DIFFSENS" is between +0.7V and +1.9V, the drive interface circuits operate LVD.

Customer can configure the drive to switch between single-ended and LVD modes using the I/O "DIFFSENS" line, or force it to operate in single-ended mode only as described later in this document.

Note 1: To operate at LVD mode, all devices on the same bus must be running in LVD mode. If you add any single-ended device to a bus that is operating in LVD mode, all devices drop back to operating in single-ended mode. This eliminates the possibility of reaching Ultra-2 SCSI transfer rates.

Note 2: Do not mix LVD drives on the same daisy chain with devices having high voltage differential (HVD) interface circuits.

Drawing No. Sheet No. Revision ６
K6610091	19/43	2005/2/23