LTC4300A-3

Features:

Bidirectional Buffer* for SDA and SCL Lines Increases Fanout
Prevents SDA and SCL Corruption During Live Board Insertion and Removal from Backplane
Logic Threshold ENABLE Input
Isolates Input SDA and SCL Lines from Output
Compatible with I2CTM, I2C Fast Mode and SMBus Standards (Up to 400kHz Operation)
1V Precharge on all SDA and SCL Lines
Supports Clock Stretching, Arbitration and Synchronization
5V to 3.3V Level Translation
High Impedance SDA, SCL Pins for VCC = 0V,VCC2 = 0V
Small 8-Pin DFN and MSOP Packages


Application

Hot Board Insertion
Servers
Capacitance Buffer/Bus Extender
Desktop Computer


Pinout




Specifications

VCC to GND ................................................. 0.3 to 7V
VCC2 to GND ............................................... 0.3 to 7V
SDAIN, SCLIN, SDAOUT, SCLOUT................. 0.3 to 7V
ENABLE ........................................................0.3 to 7V
Operating Temperature Range
LTC4300A-3C ........................................  0°C to 70°C
LTC4300A-3I ..................................... 40°C to 85°C
Storage Temperature Range
MSOP ...............................................65°C to 150°C
DFN ..................................................65°C to 125°C
Lead Temperature (Soldering, 10 sec)
MSOP Only ........................................................ 300°C


Description

The LTC®4300A-3 hot swappable 2-wire bus buffer allows I/O card insertion into a live backplane without corruption of the data and clock busses. When the connection is made, the LTC4300A-3 provides bidirectional buffering, keeping the backplane and card capacitances isolated. Rise-time accelerator circuitry allows the use of weaker DC pull-up currents while still meeting rise-time require-ments. During insertion, the SDA and SCL lines are precharged to 1V to minimize bus disturbances.

The LTC4300A-3 provides level translation between 3.3V and 5V supplies. The backplane and card can both be powered with supplies ranging from 2.7V to 5.5V. The LTC4300A-3 also incorporates a CMOS threshold ENABLE pin which forces the part into a low current mode and iso-lates the card from the backplane.  When driven to VCC, the ENABLE pin sets normal operation.

The LTC4300A-3 is  available in  the MSOP and 3mm × 3mm DFN packages.