54AC 74AC138 54ACT 74ACT138 1-of-8 Decoder Demultiplexer

Transcription

1 54AC 74AC138 54ACT 74ACT138 1-of-8 Decoder Demultiplexer General Description The AC ACT138 is a high-speed 1-of-8 decoder demultiplexer This device is ideally suited for high-speed bipolar memory chip select address decoding The multiple input enables allow parallel expaion to a 1-of-24 decoder using just three AC ACT138 devices or a 1-of-32 decoder using four AC ACT138 devices and one inverter Logic Symbols IEEE IEC TL F Features Pin Assignment for DIP Flatpak and SOIC Y ICC reduced by 50% Y Demultiplexing capability Y Multiple input enable for easy expaion Y Active LOW mutually exclusive outputs Y Outputs source sink 24 ma Y ACT138 has TTL-compatible inputs Y Standard Military Drawing (SMD) AC ACT Connection Diagrams TL F Pin Assignment for LCC March 1993 TL F AC 74AC138 54ACT 74ACT138 1-of-8 Decoder Demultiplexer TL F Pin Names A 0 A 2 E 1 E 2 E 3 O 0 O 7 Description Address Inputs Enable Inputs Enable Input Outputs FACTTM is a trademark of National Semiconductor Corporation C1995 National Semiconductor Corporation TL F 9925 RRD-B30M75 Printed in U S A

2 Functional Description The AC ACT138 high-speed 1-of-8 decoder demultiplexer accepts three binary weighted inputs (A 0 A 1 A 2 ) and when enabled provides eight mutually exclusive active-low outputs (O 0 O 7 ) The AC ACT138 features three Enable inputs two active-low (E 1 E 2 ) and one active-high (E 3 ) All outputs will be HIGH unless E 1 and E 2 are LOW and E 3 is HIGH This multiple enable function allows easy parallel expaion of the device to a 1-of-32 (5 lines to 32 lines) decoder with just four AC ACT138 devices and one inverter (see Figure 1) The AC ACT138 can be used as an 8- output demultiplexer by using one of the active LOW Enable inputs as the data input and the other Enable inputs as strobes The Enable inputs which are not used must be permanently tied to their appropriate active-high or active- LOW state Truth Table Inputs Outputs E 1 E 2 E 3 A 0 A 1 A 2 O 0 O 1 O 2 O 3 O 4 O 5 O 6 O 7 H X X X X X H H H H H H H H X H X X X X H H H H H H H H X X L X X X H H H H H H H H L L H L L L L H H H H H H H L L H H L L H L H H H H H H L L H L H L H H L H H H H H L L H H H L H H H L H H H H L L H L L H H H H H L H H H L L H H L H H H H H H L H H L L H L H H H H H H H H L H L L H H H H H H H H H H H L H e HIGH oltage Level L e LOW oltage Level X e Immaterial Logic Diagram TL F Please note that this diagram is provided only for the understanding of logic operatio and should not be used to estimate propagation delays 2

3 TL F FIGURE 1 Expaion to 1-of-32 Decoding 3

4 Absolute Maximum Rating (Note 1) If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specificatio Supply oltage ( CC ) b0 5 to a7 0 DC Input Diode Current (I IK ) I eb0 5 b20 ma I e CC a 0 5 a20 ma DC Input oltage ( I ) b0 5 to CC a 0 5 DC Output Diode Current (I OK ) O eb0 5 b20 ma O e CC a 0 5 a20 ma DC Output oltage ( O ) b0 5 to CC a 0 5 DC Output Source or Sink Current (I O ) g50 ma DC CC or Ground Current per Output Pin (I CC or I GND ) g50 ma Storage Temperature (T STG ) b65 Ctoa150 C Junction Temperature (T J ) CDIP 175 C PDIP 140 C Note 1 Absolute maximum ratings are those values beyond which damage to the device may occur The databook specificatio should be met without exception to eure that the system design is reliable over its power supply temperature and output input loading variables National does not recommend operation of FACTTM circuits outside databook specificatio DC Characteristics for AC Family Devices Symbol Parameter Recommended Operating Conditio Supply oltage ( CC ) AC ACT Input oltage ( I ) Output oltage ( O ) Operating Temperature (T A ) 74AC ACT 54AC ACT Minimum Input Edge Rate (D Dt) AC Devices IN from 30% to 70% of CC CC Minimum Input Edge Rate (D Dt) ACT Devices IN from 0 8 to 2 0 CC AC 54AC 74AC CC T T A ea25 C A e T A e () b55 Ctoa125 C b40 Ctoa85 C Typ Guaranteed Limits Units 2 0 to to 5 5 0to CC 0to CC b40 Ctoa85 C b55 Ctoa125 C 125 m 125 m Conditio IH Minimum High Level OUT e 0 1 Input oltage or CC b IL Maximum Low Level OUT e 0 1 Input oltage or CC b OH Minimum High Level I OUT eb50 ma Output oltage IN e IL or IH b12 ma I OH b24 ma b24 ma OL Maximum Low Level I OUT e 50 ma Output oltage IN e IL or IH ma I OL 24 ma ma I IN Maximum Input Leakage Current 5 5 g0 1 g1 0 g1 0 ma I e CC GND All outputs loaded thresholds on input associated with output under test 4

5 DC Characteristics for AC Family Devices (Continued) 74AC 54AC 74AC Symbol Parameter CC T T A ea25 C A e T A e () b55 Ctoa125 C b40 Ctoa85 C Units Conditio Typ Guaranteed Limits I OLD Minimum Dynamic ma OLD e 1 65 Max I OHD Output Current 5 5 b50 b75 ma OHD e 3 85 Min I CC Maximum Quiescent ma IN e CC Supply Current or GND Maximum test duration 2 0 ms one output loaded at a time Note I IN and I CC 3 0 are guaranteed to be less than or equal to the respective limit 5 5 CC I CC for 54AC 25 C is identical to 74AC 25 C DC Characteristics for ACT Family Devices 74ACT 54ACT 74ACT Symbol Parameter CC T T A ea25 C A e T A e () b55 Ctoa125 C b40 Ctoa85 C Units Conditio Typ Guaranteed Limits IH Minimum High Level OUT e 0 1 Input oltage or CC b 0 1 IL Maximum Low Level OUT e 0 1 Input oltage or CC b 0 1 OH Minimum High Level Output oltage I OUT eb50 ma IN e IL or IH b24 ma I OH b24 ma OL Maximum Low Level Output oltage I OUT e 50 ma IN e IL or IH ma I OL 24 ma I IN Maximum Input Leakage Current 5 5 g0 1 g1 0 g1 0 ma I e CC GND I CCT Maximum I CC Input ma I e CC b 2 1 I OLD Minimum Dynamic ma OLD e 1 65 Max I OHD Output Current 5 5 b50 b75 ma OHD e 3 85 Min I CC Maximum Quiescent ma IN e CC Supply Current or GND All outputs loaded thresholds on input associated with output under test Maximum test duration 2 0 ms one output loaded at a time Note I CC for 54ACT 25 C is identical to 74ACT 25 C 5

6 AC Electrical Characteristics 74AC 54AC 74AC T CC T A ea25 C A eb55 C T A eb40 C Symbol Parameter to a125 C to a85 C Units () C L e 50 pf C L e 50 pf C L e 50 pf Min Typ Max Min Max Min Max t PLH A n to O n t PHL A n to O n t PLH E 1 or E 2 to O n t PHL E 1 or E 2 to O n t PLH E 3 to O n t PHL E 3 to O n oltage Range 3 3 is 3 3 g0 3 oltage Range 5 0 is 5 0 g0 5 AC Electrical Characteristics Symbol t PLH t PHL t PLH t PHL t PLH t PHL Parameter A n to O n A n to O n E 1 or E 2 to O n E 1 or E 2 to O n E 3 to On E 3 to On oltage Range 5 0 is 5 0 g0 5 Capacitance CC () 74ACT 54ACT 74ACT T T A ea25 C A eb55 C T A eb40 C to a125 C to a85 C Units C L e 50 pf C L e 50 pf C L e 50 pf Min Typ Max Min Max Min Max Symbol Parameter Typ Units Conditio C IN Input Capacitance 4 5 pf CC e OPEN C PD Power Dissipation Capacitance 60 0 pf CC e 5 0 6

7 Ordering Information The device number is used to form part of a simplified purchasing code where the package type and temperature range are defined as follows 74ACT 138 P C QR Temperature Range Family 74AC e Commercial 54AC e Military 74ACT e Commercial TTL-Compatible 54ACT e Military TTL-Compatible Device Type Package Code P e Plastic DIP D e Ceramic DIP F e Flatpak L e Leadless Ceramic Chip Carrier (LCC) S e Small Outline (SOIC) Special ariatio X e Devices shipped in 13 reels QR e Commercial grade device with burn-in QB e Military grade device with environmental and burn-in processing shipped in tubes Temperature Range C e Commercial (b40 Ctoa85 C) M e Military (b55 Ctoa125 C) 7

8 Physical Dimeio inches (millimeters) 20 Terminal Ceramic Leadless Chip Carrier (L) NS Package Number E20A 16 Lead Ceramic Dual-In-Line Package (D) NS Package Number J16A 8

9 Physical Dimeio inches (millimeters) (Continued) 16 Lead Small Outline Integrated Circuit (S) NS Package Number M16A 16 Lead Plastic Dual-In-Line Package (P) NS Package Number N16E 9

10 54AC 74AC138 54ACT 74ACT138 1-of-8 Decoder Demultiplexer Physical Dimeio inches (millimeters) (Continued) 16 Lead Ceramic Flatpak (F) NS Package Number W16A LIFE SUPPORT POLICY NATIONAL S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION As used herein 1 Life support devices or systems are devices or 2 A critical component is any component of a life systems which (a) are intended for surgical implant support device or system whose failure to perform can into the body or (b) support or sustain life and whose be reasonably expected to cause the failure of the life failure to perform when properly used in accordance support device or system or to affect its safety or with itructio for use provided in the labeling can effectiveness be reasonably expected to result in a significant injury to the user National Semiconductor National Semiconductor National Semiconductor National Semiconductor National Semiconductores National Semiconductor Corporation GmbH Japan Ltd Hong Kong Ltd Do Brazil Ltda (Australia) Pty Ltd 2900 Semiconductor Drive Livry-Gargan-Str 10 Sumitomo Chemical 13th Floor Straight Block Rue Deputado Lacorda Franco Building 16 P O Box D F4urstenfeldbruck Engineering Center Ocean Centre 5 Canton Rd 120-3A Business Park Drive Santa Clara CA Germany Bldg 7F Tsimshatsui Kowloon Sao Paulo-SP Monash Business Park Tel 1(800) Tel (81-41) Nakase Mihama-Ku Hong Kong Brazil Nottinghill Melbourne TWX (910) Telex Chiba-City Tel (852) Tel (55-11) ictoria 3168 Australia Fax (81-41) 35-1 Ciba Prefecture 261 Fax (852) Telex NSBR BR Tel (3) Tel (043) Fax (55-11) Fax (3) Fax (043) National does not assume any respoibility for use of any circuitry described no circuit patent licees are implied and National reserves the right at any time without notice to change said circuitry and specificatio