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74VHC138 3-to-8 Decoder / Demultiplexer

74VHC138 3-to-8 Decoder / Demultiplexer

74VHC138 3-to-8 Decoder / Demultiplexer
February 1998
74VHC138 3-to-8 Decoder / Demultiplexer
General Description
The VHC138 is an advanced high speed CMOS 3-to-8 DECODER fabricated with silicon gate CMOS 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 (A0, A1 and A2) determine which one of the outputs (O 0-O 7) will go low. When enable input E3 is held low or either E 1 or E 2 is held high, decoding function is inhibited and all outputs go high. E3, E 1 and E 2 inputs are provided to ease cascade connection and for use as an address decoder for memory systems. An input protection circuit ensures that 0V to 7V can be applied to the input pins without regard to the supply voltage. This device can be used to interface 5V to 3V systems and two supply systems such as battery back up. This circuit prevents device destruction due to mismatched supply and input voltages.
Features
Ordering Code:
Commercial 74VHC138M 74VHC138SJ 74VHC138MTC 74VHC138N Package Number M16A M16D MTC16 N16E Package Description 16-Lead Molded JEDEC SOIC 16-Lead Molded EIAJ SOIC 16-Lead Molded JEDEC Type I TSSOP 16-Lead Molded DIP
Surface mount packages are also available on Tape and Reel. Specify by appending the suffix letter "X" to the ordering code.
Logic Symbols
Connection Diagram
Pin Assignment for DIP, TSSOP and SOIC
DS011537-1
IEEE / IEC
DS011537-2
Pin Descriptions
Pin Names A0-A2 E1-E2
DS011537-3
Description Address Inputs Enable Inputs Enable Input Outputs
E3 O0-O7
DS011537
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Truth Table
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Absolute Maximum Ratings (Note 1)
Recommended Operating Conditions
Note 1: Absolute Maximum Ratings are values beyond which the device may be damaged or have its useful life impaired. The databook specifications should be met, without exception, to ensure that the system design is reliable over its power supply, temperature, and output / input loading variables. Fairchild does not recommend operation outside databook specifications. Note 2: Unused inputs must be held HIGH or LOW. They may not float.
DC Electrical Characteristics
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AC Electrical Characteristics
Units
Conditions
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Physical Dimensions
inches (millimeters) unless otherwise noted
16-Lead Small Outline Integrated Circuit-JEDEC (M) Package Number M16A
16-Lead Small Outline Package-EIAJ (SJ) Package Number M16D
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Physical Dimensions
inches (millimeters) unless otherwise noted (Continued)
14-Lead Molded JEDEC SSOP Type I (TSSOP) Package Number MTC16
16-Lead Molded Dual-In-Line Package (MDIP) Package Number N16E
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74VHC138 3-to-8 Decoder / Demultiplexer
Fairchild Semiconductor Corporation Americas Customer Response Center Tel: 1-888-522-5372 Fairchild Semiconductor Europe Fax: +49 (0) 1 80-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 8 141-35-0 English Tel: +44 (0) 1 793-85-68-56 Italy Tel: +39 (0) 2 57 5631 Fairchild Semiconductor Hong Kong Ltd. 13th Floor, Straight Block, Ocean Centre, 5 Canton Rd. Tsimshatsui, Kowloon Hong Kong Tel: +852 2737-7200 Fax: +852 2314-0061 National Semiconductor Japan Ltd. Tel: 81-3-5620-6175 Fax: 81-3-5620-6179
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Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and Fairchild reserves the right at any time without notice to change said circuitry and specifications.