In this paper, a 256×40 energy-efficient ternary content addressable memory (TCAM) macro is designed and implemented in 40nm low power (LP) CMOS. Due to the thicker gate oxide in LP process, a 16T TCAM cell with p-type comparison circuits is proposed to increase the Ion/Ioff difference of the dynamic circuitry. To further improve energy efficiency, don't-care-based ripple search-lines/bit-lines are used to reduce both the switching activities and wire capacitance. Moreover, column-based data-aware power control is employed for leakage power reduction and write-ability improvements. The experimental results show a leakage power reduction of 28.9%, a search-line power reduction of 31.74% and an energy efficiency metric of the TCAM macro of 0.339 fJ/bit/search.