2-Channel, 2-Wire Bus Multiplexer with Capacitance Buffering

The LTC4305 is a 2-channel, 2-wire bus multiplexer with bus buffers to provide capacitive isolation between the upstream bus and downstream buses. Through software control, the LTC4305 connects the upstream 2-wire bus to any desired combination of downstream channels. Each channel can be pulled up to a supply voltage ranging from 2.2V to 5.5V, independent of the LTC4305 supply voltage. The downstream channels are also provided with an ALERT1-ALERT2 inputs for fault reporting.

Programmable timeout circuitry disconnects the downstream buses if the bus is stuck low. When activated, rise time accelerators source currents into the 2-wire bus pins to reduce rise time. Driving the ENABLE pin low restores all features to their default states. Three address pins provide 27 distinct addresses.

The LTC4305 is available in 16-lead (4mm × 5mm) DFN and SSOP packages.

Applications

* Nested Addressing

* 5V/3.3V Level Translator

* Capacitance Buffer/Bus Extender

* 1:2 2-Wire Multiplexer/Switch

* Connect SDA and SCL Lines with 2-Wire Bus

Commands

* Supply Independent Bidirectional Buffer for SDA

and SCL Lines Increases Fan-Out

* Programmable Disconnect from Stuck Bus

* Compatible with I2C and SMBus Standards

* Rise Time Accelerator Circuitry

* SMBus Compatible ALERT Response Protocol

* Prevents SDA and SCL Corruption During Live Board

Insertion and Removal from Backplane

* ±10kV Human Body Model ESD Ruggedness

* 16-Lead (4mm × 5mm) DFN and SSOP Packages