Datasheet

LTC4303
1
4303fb
FEATURES
DESCRIPTIO
U
TYPICAL APPLICATIO
U
APPLICATIO S
U
10k10k
5V
BACK_SCL
BACKPLANE
CONNECTOR
CARD
BACK_SDA
3.3V
3.3V
100k
ENABLE
CARD_SCL
CARD_SDA
SCLOUTSCLIN
SDAOUTSDAIN
GND
V
CC
LTC4303
READY
0.01 F
4303 TA01
10k 10k
STAGGERED
CONNECTOR
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents including 6356140, 6650174, 7032051.
Hot Swappable 2-Wire
Bus Buffer with Stuck
Bus Recovery
The LTC
®
4303 hot swappable 2-wire Bus Buffer allows I/O
card insertion into a live backplane without corruption of
the data and clock busses. When a connection is made,
the LTC4303 provides bidirectional buffering, keeping the
backplane and card capacitances isolated. If SDAOUT or
SCLOUT is low for ≥ 30ms (typ), the LTC4303 automatically
breaks the data and clock bus connection. At this time the
LTC4303 automatically generates up to 16 clock pulses on
SCLOUT in an attempt to free the bus. A connection will
be enabled automatically when the bus becomes free.
Rise-time accelerator circuitry allows the use of larger pull-
up resistance while still meeting rise-time requirements.
During insertion, the SDA and SCL lines are precharged
to 1V to minimize bus disturbances. When driven high,
ENABLE allows the LTC4303 to connect after a stop bit or
bus idle occurs. Driving ENABLE low breaks the connection
between SDAIN and SDAOUT, SCLIN and SCLOUT. READY
is an open drain output that indicates when the backplane
and card sides are connected together.
Automatic Disconnect of SDA/SCL Lines when Bus
is Stuck Low for ≥ 30ms
Recovers Stuck Busses with Automatic Clocking*
Bidirectional Buffer* for SDA and SCL Lines
Increases Fanout
Prevents SDA and SCL Corruption During Live
Board Insertion and Removal from Backplane
Pin Compatible with LTC4300A-1
±15kV Human Body Model ESD Protection
Isolates Input SDA and SCL Lines from Output
Compatible with I
2
C
TM
, I
2
C Fast-Mode and SMBus
Standards (Up to 400kHz Operation)
READY Open Drain Output
1V Precharge on All SDA and SCL Lines
High Impedance SDA, SCL Pins for V
CC
= 0V
ENABLE Gates Connection from Input to Output
MSOP 8-Pin and DFN (3mm × 3mm) Packages
Hot Board Insertion
Servers
Capacitance Buffer/Bus Extender
RAID Systems
Stuck Bus Resolved
with Automatic Clocking
SDAOUT
5V/DIV
200 s/DIV
STUCK LOW > 30ms
AUTOMATIC CLOCKING
DISCONNECT AT TIMEOUT
RECOVERS
4303 TA01b
SDAIN
5V/DIV
SCLOUT
5V/DIV

Summary of content (12 pages)