Fast decoder with low propagation delay

Question

I need to use a fast decoder to communicate with a SRAM memory, CY7C1041GN. The circuit I need to implement is the circuit suggested in the Example #5 of the document AN2408 .The suggested decoder in this example is obsolete, but I found another, even better, with a smaller Tpd, the model that I found was the SN74LVC1G139, its Tpd is in the range of 0.8ns to 3.6ns using VCC = 5V. The problem with this model is that it does not have active low Enable pin.

I supposed that the work done by the decoders in the example #5 of AN2408, could be done by logic gates, but I didn't find logic gates that are faster than the found decoders.

I searched in many places, I listed many 2x4 decoders at digikey site, I did parametric seach at Texas, Nexperia and OnSemi websites, but I didn't found a model that have a Tpd(propagation delay) as low as 3.6 ns. Does someone know, or has a tip, of a model of decoder with Enable-Low pin that is able to reach these values of Tpd ?

Answer 1

The 74x139 decoder is a common chip, you should be able to easily find them. The 'x' in between the numbers will change depending the logic levels, so pick one that's compatible with your design. (The chip you found is a 1G139, which isn't quite the same thing.)