LTC4301 Supply Independent Hot Swappable 2-Wire Bus Buffer FEATURES DESCRIPTIO Allows Bus Pull-Up Voltages Above or Below V The LTC 4301 supply independent, hot swappable, 2-wire CC Bidirectional Buffer* for SDA and SCL Lines bus buffer allows I/O card insertion into a live backplane Increases Fanout without corruption of the data and clock busses. In addi- Prevents SDA and SCL Corruption During Live Board tion, the LTC4301 allows the V , SDAIN and SCLIN pull- CC Insertion and Removal from Backplane up voltage and the SDAOUT and SCLOUT pull-up voltage Isolates Input SDA and SCL Line from Output to be independent from each other. Control circuitry 10kV Human Body Model ESD Protection prevents the backplane from being connected to the card 1V Precharge On All SDA and SCL Lines until a stop bit or a bus idle is present. When the connec- Supports Clock Stretching, Arbitration and tion is made, the LTC4301 provides bidirectional buffer- Synchronization ing, keeping the backplane and card capacitances isolated. High Impedance SDA, SCL Pins for V = 0V CC During insertion, the SDA and SCL lines are precharged to CS Gates Connection from Input to Output 1V to minimize bus disturbances. When driven low, the CS TM 2 2 Compatible with I C , I C Fast Mode and SMBus input pin allows the part to connect after a stop bit or bus Standards (Up to 400kHz Operation) idle occurs. Driving CS high breaks the connection be- Small 8-Pin MSOP and DFN (3mm 3mm) Packages tween SCLIN and SCLOUT and between SDAIN and U SDAOUT. The READY output pin indicates that the back- APPLICATIO S plane and card sides are connected together. Hot Board Insertion The LTC4301 is offered in 8-pin DFN (3mm 3mm) and Servers MSOP packages. Capacitance Buffer/Bus Extender , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Desktop Computers All other trademarks are the property of their respective owners. TM Protected by U.S. Patents including 7032051. CompactPCI and ATCA Systems TYPICAL APPLICATIO Input-Output Connection 3.3V 5V 0.01F 10k 10k V CC 10k 10k LTC4301 SCLIN SCLOUT BACK SCL CARD SCL OUTPUT INPUT SIDE SIDE 55pF 20pF SDAIN SDAOUT BACK SDA CARD SDA 1V/DIV 5V 10k CS READY GND 4301 TA01b 1s/DIV 4301 TA01 BACKPLANE CARD CONNECTOR 4301fb 1 STAGGERED CONNECTOR U ULTC4301 ABSOLUTE MAXIMUM RATINGS (Note 1) V to GND ................................................. 0.3V to 7V CC Storage Temperature Range SDAIN, SCLIN, SDAOUT, SCLOUT, CS ........ 0.3V to 7V MSOP ............................................... 65C to 150C READY ........................................................ 0.3V to 6V DFN .................................................. 65C to 125C Operating Temperature Range Lead Temperature (Soldering, 10 sec).................. 300C LTC4301C ............................................... 0C to 70C LTC4301I............................................ 40C to 85C PACKAGE/ORDER INFORMATION TOP VIEW ORDER PART ORDER PART NUMBER NUMBER CS 1 8 V TOP VIEW CC LTC4301CDD LTC4301CMS8 SCLOUT 2 7 SDAOUT CS 1 8 V CC 9 SCLOUT 2 7 SDAOUT LTC4301IDD LTC4301IMS8 SCLIN SDAIN 3 6 SCLIN 3 6 SDAIN GND 4 5 READY GND 4 5 READY DD PART MS8 PART MS8 PACKAGE MARKING* MARKING* 8-LEAD PLASTIC MSOP DD PACKAGE 8-LEAD (3mm 3mm) PLASTIC DFN T = 125C, = 200C/W JMAX JA T = 125C, = 43C/W LBBY LTBBW JMAX JA EXPOSED PAD (PIN 9) PCB CONNECTION OPTIONAL Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: