74LS42N MOTOROLA | Alldatasheet
Document overview
- Manufacturer or author: Provided By alldatasheet.com(free datasheet download site)
- PDF pages: 3
Technical content
The LSTTL/MSI SN54/74LS42 is a Multipurpose Decoder designed to ac- cept four BCD inputs and provide ten mutually exclusive outputs. The LS42 is fabricated with the Schottky barrier diode process for high speed and is completely compatible with all Motorola TTL families.
- Multifunction Capability
- Mutually Exclusive Outputs
- Demultiplexing Capability
- Input Clamp Diodes Limit High Speed Termination Effects 14 13 12 11 10 9 12345 6 VCC 16 15 A0 A1 A2 A3 9 8 7 0 1 2 3 4 5 6 GND NOTE: The Flatpak version has the same pinouts (Connection Diagram) as the Dual In-Line Package. CONNECTION DIAGRAM DIP (TOP VIEW) PIN NAMES LOADING (Note a) HIGH LOW A0 – A3 0 to 9 Address Inputs Outputs, Active LOW (Note b) 0.5 U.L. 10 U.L. 0.25 U.L. 5(2.5) U.L. NOTES: a) 1 TTL Unit Load (U.L.) = 40 µA HIGH/1.6 mA LOW. Temperature Ranges. LOGIC DIAGRAM 45 1 0 1 1 121315 12 67 9 1 2 3 4 5 60 A0 A1 A2 A3 987 VCC = PIN 16 GND = PIN 8 = PIN NUMBERS SN54/74LS42 ONE-OF-TEN DECODER LOW POWER SCHOTTKY J SUFFIX CERAMIC CASE 620-09 N SUFFIX PLASTIC CASE 648-08
ORDERING INFORMATION
VCC = PIN 16 GND = PIN 8 15 14 13 12 012345 6789 1 2 3 45679 1 0 1 1 A0 A1 A2 A3
The LS42 decoder accepts four active HIGH BCD inputs and provides ten mutually exclusive active LOW outputs, as shown by logic symbol or diagram. The active LOW outputs facilitate addressing other MSI units with LOW input enables. The logic design of the LS42 ensures that all outputs are HIGH when binary codes greater than nine are applied to the inputs. The most significant input A3 produces a useful inhibit func- tion when the LS42 is used as a one-of-eight decoder. The A3 input can also be used as the Data input in an 8-output demultiplexer application. TRUTH TABLE A 0 A 1 A 2 A 3 0 1 2 3 4 5 6 7 8 9 L H L H L H L H L H L H L H L H L L H H L L H H L L H H L L H H L L L L H H H H L L L L H H H H L L L L L L L L H H H H H H H H L H H H H H H H H H H H H H H H H L H H H H H H H H H H H H H H H H L H H H H H H H H H H H H H H H H L H H H H H H H H H H H H H H H H L H H H H H H H H H H H H H H H H L H H H H H H H H H H H H H H H H L H H H H H H H H H H H H H H H H L H H H H H H H H H H H H H H H H L H H H H H H H H H H H H H H H H L H H H H H H H = HIGH Voltage Level L = LOW Voltage Level GUARANTEED OPERATING RANGES Symbol Parameter Min Typ Max Unit VCC Supply Voltage 54 4.5 4.75 5.0 5.0 5.5 5.25 V TA Operating Ambient Temperature Range 54 –55 125 IOH Output Current — High 54, 74 –0.4 mA IOL Output Current — Low 54 4.0 8.0 mA
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified) Sb l P Limits Ui T C di iSymbol Parameter Min Typ Max Unit Test Conditions VIH Input HIGH Voltage 2.0 V Guaranteed Input HIGH Voltage for All Inputs VIL Input LOW Voltage 54 0.7 V Guaranteed Input LOW Voltage forVIL Input LOW Voltage 74 0.8 V pg All Inputs VIK Input Clamp Diode Voltage –0.65 –1.5 V VCC = MIN, IIN = –18 mA VOH Output HIGH Voltage 54 2.5 3.5 V VCC = MIN, IOH = MAX, VIN = VIHVOH O utput HIGH Voltage 74 2.7 3.5 V CC , OH , IN IH or VIL per Truth Table VOL Output LOW Voltage 54, 74 0.25 0.4 V IOL = 4.0 mA VCC = VCC MIN, VIN =V ILor VIHVOL O utput LOW Voltage 74 0.35 0.5 V IOL = 8.0 mA VIN = VIL or VIH per Truth Table IIH Input HIGH Current 20 µA VCC = MAX, VIN = 2.7 V IIH Input HIGH C urrent 0.1 mA VCC = MAX, VIN = 7.0 V IIL Input LOW Current –0.4 mA VCC = MAX, VIN = 0.4 V IOS Short Circuit Current (Note 1) –20 –100 mA VCC = MAX ICC Power Supply Current 13 mA VCC = MAX Note 1: Not more than one output should be shorted at a time, nor for more than 1 second. AC CHARACTERISTICS (TA = 25°C) Sb l P Limits Ui T C di iSymbol Parameter Min Typ Max Unit Test Conditions tPLH tPHL Propagation Delay (2 Levels) ns Figure 2 VCC = 5.0 V tPLH tPHL Propagation Delay (3 Levels) ns Figure 1 CC C L = 15 pF AC WAVEFORMS VIN VOUT 1.3 V 1.3 V 1.3 V 1.3 V tPHL tPLH Figure 1 Figure 2 1.3 V 1.3 V 1.3 V1.3 V tPLHtPHL VIN VOUT