Logic-Level Translators Simplify Systems While Maintaining Speed

Jan. 19, 2004

Flexible bidirectional level translation between 1.5-, 1.8-, 2.5-, 3.3-, and 5-V voltage nodes is possible with a new family of dual-supply-level translation transceivers. Texas Instruments' SN74LVC1T45, SN74LVC2T45, SN74AVC8T245, and SN74AVC-20T245...

Dave Bursky

Mismatched I/O voltages between microprocessors and peripheral devices continue to occur as microprocessor I/O voltages migrate to lower nodes and peripherals maintain higher voltage nodes. These transceivers also offer full configurability, with each rail configurable from 1.4 to 3.6 V in the AVC technology and 1.65 to 5.5 V in the LVC technology.

The AVC versions feature 12-mA current drive and propagation delays of just 3.5 ns (typ) when translating from 1.8 to 3.3 V. Translators in the LVC technology have a max drive strength of 32 mA and propagation delays of 4 ns (typ) when translating from 3.3 to 5 V.

These devices add further bit width flexibility to TI's existing portfolio by providing 1-, 2-, 8-, and 20-bit wide versions. The new six-pin LVC1T45 and eight-pin LVC2T45 transceivers simplify routing by enabling designers to place a single or a dual translator on the board rather than routing through a higher bit-width device. These transceivers are extremely useful for level shifting control signals from general-purpose I/Os.

Prices for the translators range from $0.40 to $2.50 each in lots of 1000 units.

Texas Instrumentswww.ti.com/tran

About the Author

Dave Bursky | Technologist

Dave Bursky, the founder of New Ideas in Communications, a publication website featuring the blog column Chipnastics – the Art and Science of Chip Design. He is also president of PRN Engineering, a technical writing and market consulting company. Prior to these organizations, he spent about a dozen years as a contributing editor to Chip Design magazine. Concurrent with Chip Design, he was also the technical editorial manager at Maxim Integrated Products, and prior to Maxim, Dave spent over 35 years working as an engineer for the U.S. Army Electronics Command and an editor with Electronic Design Magazine.