LTC4300-1/LTC4300-2 Hot Swappable 2-Wire Bus Buffers Fea T Descrip T n Bidirectional Buffer for SDA and SCL Lines The LTC 4300 series hot swappable 2-wire bus buffers Increases Fanout allow I/O card insertion into a live backplane without cor- n Prevents SDA and SCL Corruption During Live ruption of the data and clock busses. When the connection Board Insertion and Removal From Backplane is made, the LTC4300-1/LTC4300-2 provide bidirectional n Isolates Input SDA and SCL Lines From Output buffering, keeping the backplane and card capacitances 2 2 n Compatible with I C, I C Fast Mode and SMBus isolated. Rise time accelerator circuitry* allows the use of Standards (Up to 400kHz Operation) weaker DC pull-up currents while still meeting rise time n Low I Chip Disable: <1A (LTC4300-1) requirements. During insertion, the SDA and SCL lines are CC n READY Open-Drain Output (LTC4300-1) precharged to 1V to minimize bus disturbances. n 1V Precharge on All SDA and SCL Lines The LTC4300-1 incorporates a CMOS threshold digital n Supports Clock Stretching, Arbitration and ENABLE input pin, which forces the part into a low current Synchronization mode when driven to ground and sets normal operation n 5V to 3.3V Level Translation (LTC4300-2) when driven to V . It also includes an open drain READY CC n High Impedance SDA, SCL Pins for V = 0V CC output pin, which indicates that the backplane and card n Small MSOP 8-Lead Package sides are connected together. The LTC4300-2 replaces the ENABLE pin with a dedicated supply voltage pin, V , CC2 a T for the card side, providing level shifting between 3.3V n Hot Board Insertion and 5V systems. Both the backplane and card may be n Servers powered with supply voltages ranging from 2.7V to 5.5V, n Capacitance Buffer/Bus Extender with no constraints on which supply voltage is higher. n Desktop Computer The LTC4300-2 also replaces the READY pin with a digital L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and CMOS input pin, ACC, which enables and disables the rise Hot Swap and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks time accelerator currents. are the property of their respective owners. *Protected by U.S. Patents, including 6650174. The LTC4300 is available in a small 8-lead MSOP package. Typical a T V CC 3.3V C1 InputOutput Connection t PLH 0.01F R1 R2 R3 R4 24k 24k 8 24k 24k 3 2 SCLIN SCLOUT OUTPUT SIDE INPUT SIDE C2* C4* 50pF 150pF 0.5V/DIV 6 7 SDAIN SDAOUT C3* C5* LTC4300-1 430012 TA01b 1 5 200ns/DIV ENABLE READY GND 4 *CAPACITORS NOT REQUIRED 430012 TA01a IF BUS IS SUFFICIENTLY LOADED 430012fb 1 For more information www.linear.com/LTC4300-1 ion pplica ions pplica ion uresLTC4300-1/LTC4300-2 a T e m r a T p c F T (Note 1) V to GND ..................................................0.5V to 7V CC TOP VIEW V to GND (LTC4300-2) ............................ 0.5V to 7V CC2 ENABLE/V * 1 8 V CC2 CC SCLOUT 2 7 SDAOUT SDAIN, SCLIN, SDAOUT, SCLOUT ................ 0.5V to 7V SCLIN 3 6 SDAIN GND 4 5 READY/ACC* READY, ENABLE (LTC4300-1) ...................... 0.5V to 7V MS8 PACKAGE ACC (LTC4300-2) ......................................... 0.5V to 7V 8-LEAD PLASTIC MSOP Operating Temperature Range *LTC4300-2 T = 125C, = 200C/W JMAX JA LTC4300-1C/LTC4300-2C ........................ 0C to 70C LTC4300-1I/LTC4300-2I ......................40C to 85C Storage Temperature Range .................. 65C to 125C Lead Temperature (Soldering, 10 sec) ...................300C o r D i n F T LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC4300-1CMS8 PBF LTC4300-1CMS8 TRPBF LTUB 8-Lead Plastic MSOP 0C to 70C LTC4300-1IMS8 PBF LTC4300-1IMS8 TRPBF LTUC 8-Lead Plastic MSOP 40C to 85C LTC4300-2CMS8 PBF LTC4300-2CMS8 TRPBF LTVJ 8-Lead Plastic MSOP 0C to 70C LTC4300-2IMS8 PBF LTC4300-2IMS8 TRPBF LTVK 8-Lead Plastic MSOP 40C to 85C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on nonstandard lead based finish parts. For more information on lead free part markings, go to: