Electrical Requirements; Scsi Interface - Fujitsu MCM3064SS Product Manual

7.4 Electrical Requirements

7.4.1 SCSI interface

(1) Driver and receiver
For the interface signal driver, an open-collector or tri-state buffer circuit that
satisfies the following output characteristics is used. All signals are negative logic
(true = "L").
The receiver and non-driver of the SCSI device under the power-on state should
satisfy the following input characteristics on each signal.
Output characteristics
V
OL
V
OH
Input characteristics
V
IL
I
IL
V
IH
I
IH
Input hysteresis = 0.2 VDC min.
Input capacitance = 25
Note:
Recommended circuit
Driver:
Receiver: SN74LS240 or SN74LS19 (TI) (Schmitt trigger input inverter)
C156-E228-02EN
= 0.0 to 0.50 VDC (@ I
= 2.5 to 5.25 VDC
= 0.0 to 0.80 VDC
= –0.4 to 0.0 mA (@ V
= 2.0 to 5.25 VDC
= 0.0 to 0.1 mA (@ V
I
F max.
P
The SCSI device under the power-off state should satisfy the
characteristics of I
MB463 (Fujitsu) or SN7438 (TI) (Open-collector NAND gate)
= 48 mA)
OL
= 0.5 VDC)
I
= 2.7 VDC)
and I .
IL IH
7.4 Electrical Requirements
7-11