LTC4303
Hot Swappable 2-Wire
Bus Buffer with Stuck
Bus Recovery
FEATURES DESCRIPTIO
Automatic Disconnect of SDA/SCL Lines when Bus The LTC 4303 hot swappable 2-wire Bus Buffer allows I/O
is Stuck Low for 30ms card insertion into a live backplane without corruption of
Recovers Stuck Busses with Automatic Clocking* the data and clock busses. When a connection is made,
Bidirectional Buffer* for SDA and SCL Lines the LTC4303 provides bidirectional buffering, keeping the
Increases Fanout backplane and card capacitances isolated. If SDAOUT or
Prevents SDA and SCL Corruption During Live SCLOUT is low for 30ms (typ), the LTC4303 automatically
Board Insertion and Removal from Backplane breaks the data and clock bus connection. At this time the
Pin Compatible with LTC4300A-1 LTC4303 automatically generates up to 16 clock pulses on
15kV Human Body Model ESD Protection SCLOUT in an attempt to free the bus. A connection will
Isolates Input SDA and SCL Lines from Output be enabled automatically when the bus becomes free.
2 TM 2
Compatible with I C , I C Fast-Mode and SMBus
Rise-time accelerator circuitry allows the use of larger pull-
Standards (Up to 400kHz Operation)
up resistance while still meeting rise-time requirements.
READY Open Drain Output
During insertion, the SDA and SCL lines are precharged
1V Precharge on All SDA and SCL Lines
to 1V to minimize bus disturbances. When driven high,
High Impedance SDA, SCL Pins for V = 0V
CC
ENABLE allows the LTC4303 to connect after a stop bit or
ENABLE Gates Connection from Input to Output
bus idle occurs. Driving ENABLE low breaks the connection
MSOP 8-Pin and DFN (3mm 3mm) Packages
between SDAIN and SDAOUT, SCLIN and SCLOUT. READY
U
is an open drain output that indicates when the backplane
APPLICATIO S
and card sides are connected together.
Hot Board Insertion
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
Servers
All other trademarks are the property of their respective owners.
Capacitance Buffer/Bus Extender
Protected by U.S. Patents including 6356140, 6650174, 7032051.
RAID Systems
TYPICAL APPLICATIO
Stuck Bus Resolved
5V 3.3V
0.01 F
with Automatic Clocking
10k 10k
V
CC
10k 10k
LTC4303
SDAOUT
SCLIN SCLOUT
STUCK LOW > 30ms RECOVERS
5V/DIV
BACK_SCL CARD_SCL
DISCONNECT AT TIMEOUT
SDAIN
SDAIN SDAOUT
5V/DIV
BACK_SDA
CARD_SDA
AUTOMATIC CLOCKING
SCLOUT
5V/DIV
3.3V
ENABLE READY
GND
100k 4303 TA01
4303 TA01b
200 s/DIV
BACKPLANE STAGGERED CARD
CONNECTOR CONNECTOR
4303fb
1
U
ULTC4303
(Notes 1, 2)
ABSOLUTE AXI U RATI GS
SDAIN, SCLIN, SDAOUT, SCLOUT, READY
V to GND ..................................................0.3V to 7V
CC
(Note 3) ..................................................................30mA
SDAIN, SCLIN, SDAOUT, SCLOUT,
Storage Temperature Range
READY, ENABLE ...........................................0.3V to 7V
MSOP ................................................65C to 150C
Operating Temperature
DFN ....................................................65C to 125C
LTC4303C ................................................ 0C to 70C
Lead Temperature (Soldering, 10sec)
LTC4303I .............................................40C to 85C
MSOP ...............................................................300C
UUW
PACKAGE/ORDER I FOR ATIO
TOP VIEW
ENABLE 1 8 V
CC
TOP VIEW
SCLOUT 2 7 SDAOUT
9
ENABLE 1 8 V
CC
SCLIN 3 6 SDAIN
SCLOUT 2 7 SDAOUT
GND READY SCLIN 3 6 SDAIN
4 5
GND 4 5 READY
MS8 PACKAGE
DD PACKAGE
8-LEAD PLASTIC MSOP
8-LEAD (3mm 3mm) PLASTIC DFN
T = 125C, = 200C/W
JMAX JA
T = 125C, = 43C/W
JMAX JA
EXPOSED PAD (PIN 9)
PCB CONNECTION OPTIONAL
ORDER PART NUMBER DD PART MARKING* ORDER PART NUMBER MS8 PART MARKING*
LTC4303CDD LBPZ LTC4303CMS8 LTBPY
LTC4303IDD LTC4303IMS8
Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking: