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AMM-1570/1572 User’s Guide
AMM-1570/1572 User’s Guide
Stock Number:510526-00, Rev. B Page:A-4
Print Spec Number: 492379-00
Current Date: 3/7/94 ECN Date: 3/8/94
SCSI Interface

Electrical Interface

These are the specifications listed in ANSI X3.131-1986 forsingle-
ended operation.

Output Signals

All signals use open-collector or three-state drivers. Each signal
driven by a SCSI device has the following output characteristics
when measured at the SCSI device's connector:

Input Signals

SCSI inputs meet the following electrical characteristics on each sig-
nal, including both receivers and passive driv ers:
Signal Definition Characteristics
VOL Low-level output voltage 0.0 to 0.5 volts DC at 48 mA sinking
(signal assert ion)
VOH High-level output voltage 2.5 to 5.25 volts DC (signalnegation)
Signal Definition Characteristics
VIL Low-level input voltage 0.0 to 0.8 volts DC (signal true)
VIH High-level input voltage 2.0 to 5.25 volts DC (signal false)
IIL Low-level input current -0.4 to 0.0 mA at V1=0.5 volts DC
IIH High-level input current 0.0 to 0.1 mA at V1=2.7 volts DC
Minimum input hysteresis = 0.2 volts DC.
Maximum input capacitance = 25 pF (measured at the device connector closest
to the stub, if any, within the device).