MC74VHC139DTR2G ON Semiconductor

MC74VHC139 Dual 2-to-4 Decoder/ Demultiplexer The MC74VHC139 is an advanced high speed CMOS 2to4 decoder/ demultiplexer fabricated with silicon gate CMOS technology. It achieves high speed operation similar to equivalent MC74VHC139 Table 1. FUNCTION TABLE 2 4 A0a Y0a ADDRESS Inputs Outputs INPUTS 3 5 Y1a A1a ACTIVE-LOW 6 E A1 A0 Y0 Y1 Y2 Y3 OUTPUTS Y2a 7 H X X H H H H Y3a L L L L H H H 1 L L H H L H H Ea L H L H H L H L H H H H H L 14 12 ADDRESS A0b Y0b INPUTS 13 11 A1b Y1b ACTIVE-LOW 10 OUTPUTS Y2b 9 Y3b 15 Eb Figure 1. Logic Diagram En Y0 Y1 A0 Y2 Y3 A1 Figure 2. Expanded Logic Diagram (1/2 of Device) X/Y DMUX 3 3 4 4 A1a Y0a A1a Y0a 1 0 0 0 0 G 2 5 2 5 A0a Y1a A0a Y1a 3 2 1 1 1 INPUT 1 6 1 6 Ea Y2a Ea Y2a EN 2 2 7 7 Y3a Y3a 3 3 12 12 Y0b Y0b 13 13 A1b 11 Y1b A1b 11 Y1b 14 10 14 10 A0b Y2b A0b Y2b Eb 15 9 Eb 15 9 Y3b Y3b Figure 3. Input Equivalent Circuit Figure 4. IEC Logic Diagram