I²C bus address translators resolve address conflicts

June 04, 2015 // By Graham Prophet
Requiring no extra software coding or I²C multiplexers, the LTC4316/LTC4317/LTC4318 family of I²C/SMBus address translators enable multiple slaves with identical addresses, such as temperature sensors, to individually communicate with the master without conflicts.

Address conflicts arise when slaves with the same hardwired address are placed on the same bus. Traditional solutions have used I²C multiplexers or switches to software-select or pin-select the slave that needs addressing. The LTC4316-18 are transparent solutions that replace I²C muxes and switches. LTC4316/LTC4317/LTC4318 do not require any software programming or ENABLE control lines, allowing masters to make direct calls to slaves using unique translated addresses that are configured by external resistors.

The address translators provide simple address expansion for both I²C and SMBus systems, as well as voltage level translation for 2.5V, 3.3V and 5V buses. ±4 kV HBM ESD, 1V precharging, and glitch filtering of the bus pins make the address translators rugged enough for live board insertion and removal applications. A pass-through mode enables users to temporarily disable address translation and allows for general call addressing by the master. In addition, a stuck-bus timer monitors if the SCL line stays low or high for more than 30 msec, aborting the address translation and reconnecting the SDAIN to SDAOUT in any stuck bus situations.

The LTC4316 single (1 input/1 output) is available in 10-lead 3 x 3 mm DFN and 10-lead MSOP packages. The LTC4317 “Y” configuration (1 input/2 outputs) is available in a 16-lead 5 x 3 mm DFN package. The LTC4318 dual (2 inputs/2 outputs) is available in a 20-lead 4 x 4 mm QFN package. Offered over the commercial and industrial temperature ranges, pricing for the LTC4316, LTC4317 and LTC4318, starts at $1.45, $1.75 and $1.95, respectively (1000).

Linear Technology; www.linear.com/product/LTC4316, www.linear.com/product/LTC4317 and www.linear.com/product/LTC4318