Hot Swappable I2C Isolator Enables Simple Interfacing Between Busses with Isolated Grounds

The LTC4310 simplifies I2C isolation by encoding and expanding the SDA and SCL signals into four unidirectional channels, ready to be transmitted over the isolation barrier, and then decodes and recombines them using a second LTC4310, all while maintaining I2C signal integrity. The LTC4310 allows the four digital transmit and receive signals to be bridged by an Ethernet transformer to achieve communications across voltage differences of more than 1500VRMS or capacitors for lower voltage differentials.

The LTC4310 is suitable for many isolated applications including isolated I2C, SMBus and PMBus interfaces, isolated power supplies, positive-to-negative rail communications and Power over Ethernet. Aside from providing I2C isolation, the LTC4310's built-in rise time accelerators provide strong pull-up currents on SCL and SDA rising edges to meet I2C rise time specifications for heavily loaded busses. Hot Swap™ control circuitry prevents data corruption when a card is inserted or removed from a live bus. A stuck bus disconnect and recovery feature attempts to free the card if the bus is stuck low for more than 30ms. In addition, the LTC4310 is equipped with thermal shutdown protection, a READY digital output pin to indicate device operation and an enable pin for enabling the device or setting the device in a very low shutdown current mode.

The LTC4310-1 is intended for use in 100kHz systems and the LTC4310-2 is designed for 400kHz systems. Both versions are specified over the commercial and industrial temperature ranges, and offered in10-lead MSOP and 3mm x 3mm DFN packages. Available today, pricing begins at $1.48 each in 1,000 piece quantities. The LTC4310 is a welcome addition to Linear's growing family of I2C bus buffers, accelerators and multiplexers. For more information, visit www.linear.com/busbuffers.