LTC4303CMS8PBF Datasheet, PDF (1/12 Pages) Linear Dimensions Semiconductor – Hot Swappable 2-Wire Bus Buffer with Stuck Bus Recovery

FEATURES
■ _{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 VCC = 0V}
■ _{ENABLE Gates Connection from Input to Output}
■ _{MSOP 8-Pin andUDFN (3mm × 3mm) Packages}
APPLICATIO S
■ _{Hot Board Insertion}
■ _Servers
■ _{Capacitance Buffer/Bus Extender}
■ _{RAID Systems}
LTC4303
Hot Swappable 2-Wire
Bus Buffer with Stuck
Bus Recovery
DESCRIPTIO
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.
, 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.
TYPICAL APPLICATIO
5V 3.3V
10k 10k
BACK_SCL
SCLIN
V_CC
LTC4303
0.01mF
10k 10k
SCLOUT
CARD_SCL
SDAOUT
5V/DIV
BACK_SDA
3.3V
SDAIN
SDAOUT
ENABLE _GND
100k
READY
4303 TA01
BACKPLANE STAGGERED
CONNECTOR CONNECTOR
CARD
CARD_SDA
SDAIN
5V/DIV
SCLOUT
5V/DIV
Stuck Bus Resolved
with Automatic Clocking
STUCK LOW > 30ms
RECOVERS
DISCONNECT AT TIMEOUT
AUTOMATIC CLOCKING
200ms/DIV
4303 TA01b
4303fb
1