Rainbow-electronics DS2127 User Manual download pdf

General Description

The DS2127 Ultra3 LVD/SE SCSI terminator provides

low-voltage differential (LVD)/single-ended (SE) termi-

nations for 14 SCSI lines. Through the voltage on the

DIFF_CAP pin, the device detects the types of drivers

on the bus. If the device is connected in an LVD-only

bus, the DS2127 provides LVD termination. If any sin-

gle-ended devices are connected to the bus, the

DS2127 uses SE termination. If any high-voltage differ-

ential (HVD) devices are connected to the bus, the

DS2127 isolates itself from the SCSI bus. The mode

change has a built-in delay that is determined by an

integrated SPI-3 mode change filter/delay. The termi-

nating resistors can also be disconnected from the bus

by asserting the ISO pin.

For the LVD termination, the DS2127 provides 14 pre-

cisely trimmed resistors. Each resistor is biased with

two current sources to a fail-safe state. For SE termina-

tion, the DS2127 provides 14 precision 110Ω resistors

and one regulator for active-negation bias.

Applications

SCSI Array Backplane

SCSI Cables

Features

♦ Fully Compliant with Ultra2, Ultra3, Ultra160, and

Ultra320 SCSI Standards

♦ Provides LVD/SE Termination for 14 Signal Pairs

♦ Auto-Selection of LVD or SE Termination

♦ 5% Tolerance on SE and LVD Termination

Resistance

♦ Low 3pF Power-Down Capacitance

♦ Built-In Mode-Change Filter/Delay

♦ On-Board Thermal-Shutdown Circuitry

♦ SCSI Bus Hot-Plug Compatible

♦ Fully Supports Actively Negated SE SCSI Signals

DS2127

Ultra3 LVD/SE SCSI 14-Line Terminator

______________________________________________ Maxim Integrated Products 1

R13N

R13P

R12N

R12P

R11N

R11P

R10N

R10P

R9N

R9P

R8N

R8P

R2P

R2N

R3P

R3N

R4P

R4N

R5P

R5N

R6P

R6N

R7P

R7N

LQFP

GND

LVD

HS_GND

DIFF_CAP

DIFFSENS

ISO

R1N

R1P

REF

HS_GND

TPWR

R14N

R14P

DS2127

TOP VIEW

Pin Configuration

Ordering Information

Rev 0; 7/03

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

PART

TEMP RANGE

PIN-

PACKAGE

TOP

MARK

DS2127 0°C to +70°C 48 LQFP

DS2127

1 2 3 4 5 6

Summary of Contents

Page 1 - Ordering Information

General DescriptionThe DS2127 Ultra3 LVD/SE SCSI terminator provideslow-voltage differential (LVD)/single-ended (SE) termi-nations for 14 SCSI lines.

Page 2 - ELECTRICAL CHARACTERISTICS

DS2127Ultra3 LVD/SE SCSI 14-Line Terminator2 _____________________________________________________________________ABSOLUTE MAXIMUM RATINGSELECTRICAL C

Page 3

DS2127Ultra3 LVD/SE SCSI 14-Line Terminator_____________________________________________________________________ 3Note 1: All voltages are referenced

Page 4 - Pin Description

DS2127Ultra3 LVD/SE SCSI 14-Line Terminator4 _____________________________________________________________________Pin DescriptionPIN NAME FUNCTION1, 2

Page 5 - Detailed Description

Detailed DescriptionThe DS2127 provides dual-mode active terminatorswith auto-switching SE and LVD termination for 14 SCSIlines. The DIFFSENSE signal

Page 6 - Package Information

DS2127Ultra3 LVD/SE SCSI 14-Line TerminatorMaxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Max

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Rainbow-electronics DS2127 User Manual

Browse online or download User Manual for Control panel Rainbow-electronics DS2127. Rainbow Electronics DS2127 User Manual

Summary of Contents

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