Hitachi HUS103036FL3800, HUS103036FL3600, HUS103030FL3800 guide

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