Maxim Integrated Products

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DS3205

Hot-Swappable Bus Buffer for

General Description

The DS3205 bus buffer enables hot insertion and

extraction

of

boards

without

corruption

of

the

backplane’s 2-wire bus (I

When a board is inserted, the DS3205 presents high-

impedance SCL

and

SDA

connections

to

the

operation,

the

DS3205

provides

bidirectional

buffering to keep backplane and board capacitances

isolated.

Rise-time accelerators on each 2-wire bus pin enable

the use of lower current pullup resistors while still

meeting rise-time requirements.

Applications

Hot-Swappable Boards for AdvancedTCA

CompactPCI

Chassis-Oriented Telecom, Datacom,

Computing, and Storage Systems

Capacitance Buffer

Bus Extender

Fault Isolator

Ordering Information

PART

TEMP RANGE

PIN-

PACKAGE

PKG

CODE

DS3205DN+

-40

°C to +85°C 14 TDFN

T1433-1

+Denotes a lead-free package.

Features

♦ Bidirectional Buffer for SCL and SDA Lines

IPMI, and ATCA

♦ Prevents Corruption of System SCL and SDA

Lines During Live Insertion/Removal of Boards

♦ Increases Fanout by Connecting Board Bus to

Backplane Bus with < 10pF Additional Load

♦ Automatically Delays Initial Bus Connection

Until Both Bus Segments Are Idle

♦ 1V Precharge on SCL and SDA Lines

♦ ENABLE Input Pin Connects or Isolates Buses

♦ READY Output Pin Indicates “Connected”

♦ FAULT Output Pin Indicates “Stuck Bus”

♦ Optional Rise-Time Accelerators on All Bus

Pins

♦ Configurable Rise-Time Accelerator Slew Rate

Threshold (0.8V/

μs or 1.25V/μs)

♦ Supports Clock Stretching and Multiple Bus

Master Arbitration and Synchronization

♦ Optionally Disconnects Board from Backplane

When Bus is Stuck Low for ≥ 30ms

♦ Optionally Attempts to Recover a Stuck Bus by

Clocking Board SCL

♦ ±15kV ESD Protection (Human Body Model) on

Bus Pins

♦ Wide Operating Voltage Range: 2.7V to 5.5V

♦ 5V Tolerant I/Os

♦ Tiny 14-Pin, 3mm x 3mm TDFN Package

Rev: 111607

SMBus is a trademark of Intel Corp.

ATCA, AdvancedTCA, and CompactPCI are registered trademarks of PCI Industrial Computer Manufacturers Group (PICMG).