TC74AC138P/F/FT TOSHIBA CMOS Digital Integrated Circuit Silicon Monolithic TC74AC138P, TC74AC138F, TC74AC138FT 3-to-8 Line Decoder The TC74AC138 is an advanced high speed CMOS 3-to-8 LINE TC74AC138P DECODER fabricated with silicon gate and double-layer metal 2 wiring C MOS technology. It achieves the high speed operation similar to equivalent Bipolar Schottky TTL while maintaining the CMOS low power dissipation. When the device is enabled, 3 Binary Select inputs (A, B and C) determine which one of the outputs ( Y0 - Y7 ) will go low. When enable input G1 is held low or either G2A or G2B is held high, decoding function is inhibited and all outputs go high. G1, G2A , and G2B inputs are provided to ease cascade TC74AC138F connection and for use as an address decoder for memory systems. All inputs are equipped with protection circuits against static discharge or transient excess voltage. Features High speed: t = 5.9 ns (typ.) at V = 5 V pd CC Low power dissipation: I = 8 A (max) at Ta = 25C CC TC74AC138FT High noise immunity: V = V = 28% V (min) NIH NIL CC Symmetrical output impedance: I = I = 24 mA (min) OH OL Capability of driving 50 transmission lines. Balanced propagation delays: t t pLH pHL Wide operating voltage range: V = 2 to 5.5 V CC (opr) Pin and function compatible with 74F138 Weight DIP16-P-300-2.54A : 1.00 g (typ.) SOP16-P-300-1.27A : 0.18 g (typ.) TSSOP16-P-0044-0.65A : 0.06 g (typ.) Start of commercial production 1986-05 1 2014-03-01 TC74AC138P/F/FT Pin Assignment A 1 16 V CC B 2 15 Y0 C 14 Y1 3 G 2A 4 13 Y2 G2B 5 12 Y3 G1 6 11 Y4 Y7 7 10 Y5 GND 8 9 Y6 (top view) IEC Logic Symbol BIN/OCT DMUX (1) (15) (1) (15) A 1 0 Y0 A 0 0 Y0 0 (2) (14) (2) (14) B 2 1 Y1 B G 1 Y1 7 (3) (13) (3) (13) C 4 2 Y2 C 2 2 Y2 (12) (12) 3 Y3 3 Y3 (11) (11) 4 Y4 4 Y4 & & (6) (10) (6) (10) G1 5 Y5 G1 5 Y5 (4) (9) (4) (9) G2A EN 6 Y6 G2A 6 Y6 (5) (7) (5) (7) G2B 7 Y7 G2B 7 Y7 Truth Table Inputs Outputs Selected Enable Select Output Y0 Y1 Y2 Y3 Y4 Y5 Y 6 Y 7 G1 G2A G2B C B A L X X X X X H H H H H H H H None X H X X X X H H H H H H H H None X X H X X X H H H H H H H H None H L L L L L L H H H H H H H Y 0 H L L L L H H L H H H H H H Y 1 H L L L H L H H L H H H H H Y 2 H L L L H H H H H L H H H H Y 3 H L L H L L H H H H L H H H Y 4 H L L H L H H H H H H L H H Y 5 H L L H H L H H H H H H L H Y 6 H L L H H H H H H H H H H L Y 7 X: Dont care 2 2014-03-01