UNISONIC TECHNOLOGIES CO., LTD U74HCT138 CMOS IC 3-TO-8 LINE DECODERS / DEMULTIPLEXERS DESCRIPTION The U74HCT138 decodes a three−bit Address to 1−of−8 active−low outputs. This device features three Chip Select inputs, two active−low and one active−high, to facilitate the demultiplexing, cascading and chip−selecting functions. The demultiplexing function is accomplished by using the Address inputs to select the desired device output. One of the Chip Selects is used as a data input while the other Chip Selects are held in their active states. FEATURES * Operate from 4.5V to 5.5V * Low Input Current:1.0uA Max * Low Power Consumption: 8μA Max * Typical tPD=15ns * Inputs are TTL voltage compatible ORDERING INFORMATION Ordering Number Lead Free Halogen Free U74HCT138L-S16-R U74HCT138G-S16-R U74HCT138L-S16-T U74HCT138G-S16-T www.unisonic.com.tw Copyright © 2011 Unisonic Technologies Co., Ltd Package Packing SOP-16 SOP-16 Tape Reel Tube 1 of 5 QW-R502-642.A U74HCT138 PIN CONFIGURATION A0 1 16 VCC A1 2 15 Y0 A2 3 14 Y1 E1 4 13 Y2 E2 5 12 Y3 E3 6 11 Y4 Y7 7 10 Y5 GND 8 9 Y6 FUNCTION TABLE INPUTS E3 A0 H X X X X H X X X X L X L L H L L L H H L L H L L L H H L L H L L L H H L L H L L L H H Note:H : High voltage level E1 CMOS IC E2 OUTPUTS A1 A2 Y0 X X H X X H X X H L L L L L H H L H H L H L H H L H H H H H H H H L : Low voltage level UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw Y1 Y2 H H H H H H H H L H H L H H H H H H H H H H X : Don’t care Y3 Y4 Y5 Y6 Y7 H H H H H H L H H H H H H H H H H H L H H H H H H H H H H H L H H H H H H H H H H H L H H H H H H H H H H H L 2 of 5 QW-R502-642.A U74HCT138 LOGIC SYMBOL LOGIC DIAGRAM E1 CMOS IC Y0 E2 E3 Y1 Y2 Y3 Y4 A0 Y5 Y6 A1 Y7 A2 UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 3 of 5 QW-R502-642.A U74HCT138 CMOS IC ABSOLUTE MAXIMUM RATING PARAMETER SYMBOL RATINGS UNIT Supply Voltage VCC -0.5 ~ 7.0 V Input Clamp Current(VI<0 or VI>VCC) IIK ±20 mA Output Clamp Current(VO<0 or VO>VCC) IOK ±20 mA Continuous Output Current(VO=0 to VCC) IO ±25 mA VCC or GND Current ICC ±50 mA Storage Temperature TSTG -65 ~ + 150 ℃ Note: Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied. RECOMMENDED OPERATING CONDITIONS PARAMETER Supply Voltage Input Voltage Output Voltage Operating Temperature Input Rise or Fall Times SYMBOL VCC VIN VOUT TA tR, tF SYMBOL VIH VIL High-Level Output Voltage VOH Low-Level Output Voltage VOL Input Leakage Current Quiescent Supply Current II(LEAK) ICC Additional Quiescent Supply Current △ICC Input Capacitance CI TEST CONDITIONS VCC=4.5V~5.5V VCC=4.5V~5.5V VCC=4.5V, IOH=-20μA VCC=4.5V, IOH=-4mA VCC=4.5V, IOL=20μA VCC=4.5V, IOL=4mA VCC=5.5V, VIN= VCC or GND VCC=5.5V, VIN=VCC or GND, IOUT=0 One input at 0.5V or 2.4V,other inputs at 0 or Vcc VCC=4.5V~5.5V MIN TYP MAX UNIT 2.0 V 0.8 V 4.4 4.499 V 3.98 4.3 V 0.001 0.1 V 0.17 0.26 V ±0.1 ±100 nA 8 μA 1.4 2.4 mA 3 10 pF SWITCHING CHARACTERISTICS(TA=25℃,see TEST CIRCUIT AND WAVEFORMS) PARAMETER Propagation delay from input (An) to output( Yn ) Propagation delay from input ( En ) to output( Yn ) Output Transition Time VCC=4.5V~5.5V MIN TYP MAX UNIT 4.5 5.0 5.5 V 0 VCC V 0 VCC V -40 +85 ℃ 500 ns ELECTRICAL CHARACTERISTICS(TA=25℃) PARAMETER High-Level input voltage Low-Lever output voltage TEST CONDITIONS Operating SYMBOL tPLH/tPHL tPLH/tPHL tTLH/tTHL TEST CONDITIONS VCC =4.5V, CL=50pF VCC =5.5V, CL=50pF VCC =4.5V, CL=50pF VCC =5.5V, CL=50pF VCC =4.5V, CL=50pF VCC =5.5V, CL=50pF MIN TYP MAX UNIT 23 36 ns 17 32 ns 22 33 ns 18 30 ns 12 15 ns 11 14 ns OPERATING CHARACTERISTICS PARAMETER Power Dissipation Capacitance SYMBOL CPD TEST CONDITIONS No load UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw MIN TYP MAX UNIT 85 pF 4 of 5 QW-R502-642.A U74HCT138 CMOS IC TEST CIRCUIT AND WAVEFORMS Test Circuit Propagation Delay and Output Tansition Times Note: CL includes probe and jig capacitance. All input pulses are supplied by generators having the following characteristics: Zo = 50Ω, tR =6ns, tF =6ns. UTC assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all UTC products described or contained herein. UTC products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 5 of 5 QW-R502-642.A