74HC138 3 TO 8 LINE DECODER DEMULTIPLEXER Description Pin Assignments The 74HC138 is a high speed CMOS device. The device accepts a three bit binary weighted address on input pins A0, A1 and A2 and when enabled will produce one active low output with the remaing seven being high. There are two active LOW enable inputs E1 and E2, and one active HIGH enable input E3. The disabled device state results in all outputs being high. The enable state occurs with E1 and E2 asserted low and E3 asserted high. The multiple enable lines allow for the parallel expansion of decoders to create 4-to-16 line versions with no additional parts and 5-to-32 versions with the addition of a single inverter. Features Wide Supply Voltage Range from 2.0V to 6.0V Sinks or sources 8 mA at V = 4.5V CC CMOS low power consumption Schmitt Trigger Action at All Inputs Applications Inputs Accept up to 6.0V Memory chip select decoding ESD Protection Tested per JESD 22 Demultiplexing Exceeds 200-V Machine Model (A115-A) Single line peripheral control Exceeds 2000-V Human Body Model (A114-A) Allow simple serial bit streams from a microcontroller to control as Exceeds 1000-V Charged Device Model (C101C) many peripheral lines as needed Latch-Up Exceeds 100mA per JESD 78D, Class II Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. Green Device (Note 3) Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. 2. See 74HC138 Pin Descriptions Pin Number Pin Name Description 1 A0 Address Input 0 2 A1 Address Input 1 3 A2 Address Input 2 4 Enable Input 1 (active LOW) E1 5 Enable Input 2 (active LOW) E2 6 E3 Enable Input 3 (active HIGH) 7 Y7 Output 7 (active LOW) 8 GND Ground 9 Y6 Output 6 (active LOW) 10 Y5 Output 5 (active LOW) 11 Y4 Output 4 (active LOW) 12 Y3 Output 3 (active LOW) 13 Y2 Output 2 (active LOW) 14 Y1 Output 1 (active LOW) 15 Y0 Output o (active LOW) 16 Vcc Supply Voltage Function Table Diagram Control Input Output E3 A2 A1 A0 E1 E2 Y7 Y6 Y5 Y4 Y3 Y2 Y1 Y0 H X X X X X H H H H H H H H X H X X X L L L H L L L H H H H H H H L L L H H H H H H H L H L H L H H H H H L H H L H H H H H H L H H H H L L H H H L H H H H H L H H H L H H H H H H H L H L H H H H H H H H H L H H H H H H H 2 of 10 June 2013 74HC138 Diodes Incorporated www.diodes.com Document number: DS35488 Rev.3 - 2