Features

• Bidirectional I²C Communication Between Two Isolated Buses
• Full Isolation with Inexpensive Ethernet Transformers or Capacitors
• Low Voltage Level Shifting
• I²C Maximum Operating Frequency:
  100kHz for LTC4310-1
  400kHz for LTC4310-2
• I2C Specification Compliant V_OL, V_IL
• ±5kV Human Body Model ESD Protection
• Rise Time Accelerators
• SDA, SCL Hot-Swapping
• Very Low Shutdown Current
• Stuck Bus Disconnect and Recovery
• Thermal Shutdown
• 10-Lead MSOP and 3mm × 3mm DFN Packages

Typical Application

Description

The LTC4310 provides bidirectional I²C communications between two I²C buses whose grounds are isolated from one another. Each LTC4310 encodes I²C bus logic states into signals that are transmitted across an isolation barrier to another LTC4310. The receiving LTC4310 decodes the transmission and drives its l²C bus to the appropriate logic state. The isolation barrier can be bridged by an inexpensive Ethernet, or other transformer, to achieve communications across voltage differences reaching thousands of volts, or it can be bridged by capacitors for lower voltage isolation. The LTC4310-1 is intended for use in 100kHz I²C systems. The LTC4310-2 is intended for 400kHz I²C systems.

Rise time accelerators provide strong pull-up currents on SCL and SDA rising edges to meet rise time specifications for heavily loaded systems. Data and clock Hot Swap™ circuitry prevent data corruption when a card is inserted into or removed from a live bus. When a bus is stuck low for 37ms, the LTC4310 turns off its pull-down devices and generates up to sixteen clocks and a STOP bit in an attempt to free the bus. Driving EN low sets the LTC4310 in a very low current shutdown mode to conserve power.