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: