Overview: MOTOROLA
SEMICONDUCTOR TECHNICAL DATA 18ĆBit Switchable Active
SCSIĆ2 Bus Terminator (110Ω)
With Voltage Regulator and
Inverted Disconnect MCCS142238 The MCCS142238™ is a precision 18-bit switchable active SCSI-2 bus terminator with an on-board 2.85V regulator. When the Disconnect pin is HIGH according to the truth table below, the MCCS142238 provides 110Ω ±5% precision resistor pull-ups to a 2.85V reference for termination of 18-bits in a SCSI-2 standard bus system interface.
When the Disconnect pin is LOW, the device outputs are in the high impedance state on all 18 bits. The regulator is also turned off, greatly reducing standby power. Even with no Termpwr applied, the outputs remain in the high impedance state. 18-BIT SWITCHABLE ACTIVE SCSI-2
BUS TERMINATOR • Complies With SCSI and SCSI-2 Standards • Pin Compatible With UC5609 • For Opposite Disconnect Polarity See Motorola’s MCCS142236 • 18 Switchable 110Ω Terminating Resistors • 4pF Channel Capacitance During Disconnect • Fully Supports Active Negation (Sinks Minimum of 220mA) • Built-In 2.85V Regulator With Low Dropout Voltage • Very Low Supply Current When Resistors Are Disabled (150µA Max) • –650mA Source Current • Thermal Shutdown Protection • Thin Profile Surface Mount Package: 28-Lead SOIC DW SUFFIX 28–LEAD WIDE SOIC PACKAGE
CASE 751F-04 The regulator has a guaranteed dropout voltage of less than 900mV, allowing regulation of supply voltages less than 4.0V. The MCCS142238 is protected by thermal shutdown.
