Fujitsu MCM3064SS, MCP3064SS, MCP3130SS, MCM3130SS manual Electrical Requirements, Scsi interface

7.4 Electrical Requirements

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

VOL = 0.0 to 0.50 VDC (@ IOL = 48 mA)

VOH = 2.5 to 5.25 VDC

Input characteristics

VIL = 0.0 to 0.80 VDC

IIL = –0.4 to 0.0 mA (@ VI = 0.5 VDC)

VIH = 2.0 to 5.25 VDC

IIH = 0.0 to 0.1 mA (@ VI = 2.7 VDC)

Input hysteresis = 0.2 VDC min.

Input capacitance = 25 PF max.

Note:	The SCSI device under the power-off state should satisfy the
	characteristics of IIL and IIH.

Recommended circuit

Driver: MB463 (Fujitsu) or SN7438 (TI) (Open-collector NAND gate)

Receiver: SN74LS240 or SN74LS19 (TI) (Schmitt trigger input inverter)

C156-E228-02EN 7-11