IN74LS138

TECHNICAL DATA IN74LS138 3-to-8-Line Decoder/Demultiplexer This schottky-clamped TTL MSI circuit is designed to be used in high-performance memory-decording or data-routing applications requiring very short propagation delay time. In high-performance memory systems this decode can be used to minimize the effects of system decoding. When employed

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with high-speed memories utilizing a fast enable circuit the delay times of this decorder and the enable time of the memory are usually less than the typical access times of the memory. This means that the effective system delay introduced by the schottkyclampled system decoder is negligible. • Designed Specifically for High Speed Memory Decoders and Data Transmission Systems • Incorporate 3 Enabler Inputs to Simplify Cascading AND/OR Data Reception • Schottky Clamped for High Performance ORDERING INFORMATION IN74LS138N Plastic IN74LS138D SOIC TA = 0° to 70° C for all packages PIN ASSIGNMENT LOGIC DIAGRAM FUNCTION TABLE Inputs CS1 CS2 CS3 X X H X H X L X X H H H H H H H H L L L L L L L L L L L L L L L L A2 A1 A0 X X X X X X X X X L L L L H H H H L L H H L L H H L H L H L H L H Outputs Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 H H H H H H H H 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 L H H H H H H H H L H H H H H H H H L H H H H H H H H L H H H H H H H H L H H H H H H H H L H H H H H H H H L PIN 16 =VCC PIN 8 = GND w w w .d e e h s a t a . u t4 m o c H = high level (steady state) L = low level (steady state) X = don’t care 1 www.DataSheet4U.com IN74LS138 MAXIMUM RATINGS* Symbol VCC VIN VOUT Tstg * Parameter Supply Voltage Input Voltage Output Voltage Storage Temperature Range Value 7.0 7.0 5.5 -65 to +150 Unit V V V °C Maximum Ratings are those values beyond which damage to the device may occur. Functional operation should be restricted to the Recommended Operating Conditions. RECOMMENDED OPERATING CONDITIONS Symbol VCC VIH VIL IOH IOL TA Supply Voltage High Level Input Voltage Low Level Input Voltage High Level Output Current Low Level Output Current Ambient Temperature Range 0 Parameter Min 4.75 2.0 0.8 -0.4 8.0 +70 Max 5.25 Unit V V V mA mA °C DC ELECTRICAL CHARACTERISTICS over full operating conditions Guaranteed Limit Symbol VIK VOH VOL IIH IIL IO ICC Parameter Input Clamp Voltage High Level Output Voltage Low Level Output Voltage High Level Input Current Low Level Input Current Output Short Circuit Current Supply Current Test Conditions VCC = min, IIN = -18 mA VCC = min, IOH = -0.4 mA VCC = min, IOL = 4 mA VCC = min, IOL = 8 mA VCC = max, VIN = 2.7 V VCC = max, VIN = 7.0 V VCC = max, VIN = 0.4 V VCC = max, VO = 0 V (Note 1) VCC = max Outputs enabled and open -20 2.7 0.4 0.5 20 0.1 -0.4 -100 10 µA mA mA mA mA Min Max -1.5 Unit V V V Note 1: Not more than one output should be shorted at a time, and duration should not exceed one second. 2