 |
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
| Datasheet File OCR Text: |
| 1-OF-8 DECODER/ DEMULTIPLEXER The LSTTL / MSI SN54 / 74LS138 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 expansion to a 1-of-24 decoder using just three LS138 devices or to a 1-of-32 decoder using four LS138s and one inverter. The LS138 is fabricated with the Schottky barrier diode process for high speed and is completely compatible with all Motorola TTL families. SN54/74LS138 1-OF-8 DECODER / DEMULTIPLEXER LOW POWER SCHOTTKY * * * * * Demultiplexing Capability Multiple Input Enable for Easy Expansion Typical Power Dissipation of 32 mW Active Low Mutually Exclusive Outputs Input Clamp Diodes Limit High Speed Termination Effects CONNECTION DIAGRAM DIP (TOP VIEW) VCC 16 O0 15 O1 14 O2 13 O3 12 O4 11 O5 10 O6 9 NOTE: The Flatpak version has the same pinouts (Connection Diagram) as the Dual In-Line Package. 16 1 J SUFFIX CERAMIC CASE 620-09 16 1 N SUFFIX PLASTIC CASE 648-08 1 A0 2 A1 3 A2 4 E1 5 E2 6 E3 7 O7 8 GND LOADING (Note a) HIGH LOW 0.25 U.L. 0.25 U.L. 0.25 U.L. 5 (2.5) U.L. 16 1 PIN NAMES A0 - A2 E1, E2 E3 O0 - O7 Address Inputs Enable (Active LOW) Inputs Enable (Active HIGH) Input Active LOW Outputs (Note b) D SUFFIX SOIC CASE 751B-03 0.5 U.L. 0.5 U.L. 0.5 U.L. 10 U.L. ORDERING INFORMATION SN54LSXXXJ SN74LSXXXN SN74LSXXXD Ceramic Plastic SOIC NOTES: a) 1 TTL Unit Load (U.L.) = 40 A HIGH/1.6 mA LOW. b) The Output LOW drive factor is 2.5 U.L. for Military (54) and 5 U.L. for Commercial (74) Temperature Ranges. LOGIC DIAGRAM A2 3 2 A1 1 A0 4 E1 E2 E3 5 6 LOGIC SYMBOL VCC = PIN 16 GND = PIN 8 = PIN NUMBERS 123 456 12 3 A0 A1 A2 E O0 O1 O2 O3 O4 O5 O6 O7 15 14 13 12 11 10 9 7 VCC = PIN 16 GND = PIN 8 7 9 10 11 12 13 14 15 O7 O6 O5 O4 O3 O2 O1 O0 FAST AND LS TTL DATA 5-1 SN54/74LS138 FUNCTIONAL DESCRIPTION The LS138 is a high speed 1-of-8 Decoder/Demultiplexer fabricated with the low power Schottky barrier diode process. The decoder accepts three binary weighted inputs (A0, A1, A2) and when enabled provides eight mutually exclusive active LOW Outputs (O0 - O7). The LS138 features three Enable inputs, two active LOW (E1, E2) and one active HIGH (E3). All outputs will be HIGH unless E1 and E2 are LOW and E3 is HIGH. This multiple enable function allows easy parallel expansion of the device to a 1-of-32 (5 lines to 32 lines) decoder with just four LS138s and one inverter. (See Figure a.) The LS138 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 E1 H X X L L L L L L L L E2 X H X L L L L L L L L E3 X X L H H H H H H H H A0 X X X L H L H L H L H A1 X X X L L H H L L H H A2 X X X L L L L H H H H O0 H H H L H H H H H H H O1 H H H H L H H H H H H O2 H H H H H L H H H H H OUTPUTS O3 H H H H H H L H H H H O4 H H H H H H H L H H H O5 H H H H H H H H L H H O6 H H H H H H H H H L H O7 H H H H H H H H H H L H = HIGH Voltage Level L = LOW Voltage Level X = Don't Care A0 A1 A2 LS04 A3 A4 H 123 A0 A1 A2 LS138 O0 O1 O2 O3 O4 O5 O6 O7 E A0 A1 A2 LS138 O0 O1 O2 O3 O4 O5 O6 O7 123 E A0 A1 A2 LS138 O0 O1 O2 O3 O4 O5 O6 O7 123 E A0 A1 A2 LS138 O0 O1 O2 O3 O4 O5 O6 O7 123 E O0 O31 Figure a FAST AND LS TTL DATA 5-2 SN54/74LS138 GUARANTEED OPERATING RANGES Symbol VCC TA IOH IOL Supply Voltage Operating Ambient Temperature Range Output Current -- High Output Current -- Low Parameter 54 74 54 74 54, 74 54 74 Min 4.5 4.75 - 55 0 Typ 5.0 5.0 25 25 Max 5.5 5.25 125 70 - 0.4 4.0 8.0 Unit V C mA mA DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified) Limits Symbol S bl VIH VIL VIK VOH Parameter P Input HIGH Voltage Input LOW Voltage Input Clamp Diode Voltage Output HIGH Voltage O Vl 54 74 54, 74 VOL Output LOW Voltage 74 Input HIGH Current Input LOW Current Short Circuit Current (Note 1) Power Supply Current - 20 0.35 0.5 20 0.1 - 0.4 -100 10 V A mA mA mA mA 2.5 25 2.7 54 74 - 0.65 3.5 35 3.5 0.25 0.4 Min 2.0 0.7 0.8 - 1.5 V V V V Typ Max Unit Ui V V Test C di i T Conditions Guaranteed Input HIGH Voltage for All Inputs Guaranteed Input LOW Voltage for p g All Inputs VCC = MIN, IIN = - 18 mA VCC = MIN, IOH = MAX, VIN = VIH MIN, MAX, or VIL per Truth Table IOL = 4.0 mA IOL = 8.0 mA VCC = VCC MIN, VIN = VIL or VIH per Truth Table IIH IIL IOS ICC VCC = MAX, VIN = 2.7 V VCC = MAX, VIN = 7.0 V VCC = MAX, VIN = 0.4 V VCC = MAX VCC = MAX Note 1: Not more than one output should be shorted at a time, nor for more than 1 second. AC CHARACTERISTICS (TA = 25C) Symbol S bl tPLH tPHL tPLH tPHL tPLH tPHL tPLH tPHL Parameter P Propagation Delay Address to Output Propagation Delay Address to Output Propagation Delay E1 or E2 Enable to Output Propagation Delay E3 Enable to Output Levels of Delay 2 2 3 3 2 2 3 3 Limits Min Typ 13 27 18 26 12 21 17 25 Max 20 41 27 39 18 32 26 38 Unit Ui ns ns ns ns Test C di i T Conditions VCC = 5.0 V 50 CL = 15 pF AC WAVEFORMS VIN 1.3 V tPHL VOUT 1.3 V 1.3 V tPLH 1.3 V VOUT VIN 1.3 V tPHL 1.3 V tPLH 1.3 V 1.3 V Figure 1 Figure 2 FAST AND LS TTL DATA 5-3 |
Price & Availability of ON2823
 |
|
|
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
| [Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
|
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |