TECHNICAL DATA IN74HCT138A 1-of-8 Decoder/Demultiplexer High-Performance Silicon-Gate CMOS The IN74HCT138A is identical in pinout to the LS/ALS138. The IN74HCT138A may be used as a level converter for interfacing TTL or NMOS outputs to High Speed CMOS inputs. The IN74HCT138A decodes a three-bit Address to one-of-eight active-lot 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. • TTL/NMOS Compatible Input Levels • Outputs Directly Interface to CMOS, NMOS, and TTL • Operating Voltage Range: 4.5 to 5.5 V • Low Input Current: 1.0 µA ORDERING INFORMATION IN74HCT138AN Plastic IN74HCT138AD SOIC TA = -55° to 125° C for all packages PIN ASSIGNMENT LOGIC DIAGRAM FUNCTION TABLE Inputs PIN 16 =VCC PIN 8 = GND Outputs CS1 CS2 CS3 A2 A1 A0 Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 X X H X H X L X X X X X X X X X X X H H H H 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 L L L L L L L L L L L L L H H L H L H L H H H H L H H H H L H H H H L H H H H H H H H H H H H H H H H H H H H L L L L L L L L H H H H L L H H L H L H H H H H H H H H H H H H H H H H L H H H H L H H H H L H H H H L H = high level (steady state) L = low level (steady state) X = don’t care Rev. 00 IN74HCT138A MAXIMUM RATINGS* Symbol Parameter Value Unit -0.5 to +7.0 V VCC DC Supply Voltage (Referenced to GND) VIN DC Input Voltage (Referenced to GND) -1.5 to VCC +1.5 V DC Output Voltage (Referenced to GND) -0.5 to VCC +0.5 V DC Input Current, per Pin ±20 mA IOUT DC Output Current, per Pin ±25 mA ICC DC Supply Current, VCC and GND Pins ±50 mA PD Power Dissipation in Still Air, Plastic DIP+ SOIC Package+ 750 500 mW -65 to +150 °C 260 °C VOUT IIN Tstg TL Storage Temperature Lead Temperature, 1 mm from Case for 10 Seconds (Plastic DIP or SOIC Package) * Maximum Ratings are those values beyond which damage to the device may occur. Functional operation should be restricted to the Recommended Operating Conditions. +Derating - Plastic DIP: - 10 mW/°C from 65° to 125°C SOIC Package: : - 7 mW/°C from 65° to 125°C RECOMMENDED OPERATING CONDITIONS Symbol VCC VIN, VOUT Parameter DC Supply Voltage (Referenced to GND) DC Input Voltage, Output Voltage (Referenced to GND) TA Operating Temperature, All Package Types tr, tf Input Rise and Fall Time (Figure 2) Min Max Unit 4.5 5.5 V 0 VCC V -55 +125 °C 0 500 ns This device contains protection circuitry to guard against damage due to high static voltages or electric fields. However, precautions must be taken to avoid applications of any voltage higher than maximum rated voltages to this high-impedance circuit. For proper operation, VIN and VOUT should be constrained to the range GND≤(VIN or VOUT)≤VCC. Unused inputs must always be tied to an appropriate logic voltage level (e.g., either GND or VCC). Unused outputs must be left open. Rev. 00 IN74HCT138A DC ELECTRICAL CHARACTERISTICS (Voltages Referenced to GND) VCC Symbol Parameter Test Conditions Guaranteed Limit V 25 °C to -55°C ≤85 °C ≤125 °C Unit VIH Minimum HighLevel Input Voltage VOUT=0.1 V or VCC-0.1 V ⎢IOUT⎢≤ 20 µA 4.5 5.5 2.0 2.0 2.0 2.0 2.0 2.0 V VIL Maximum Low Level Input Voltage VOUT=0.1 V or VCC-0.1 V ⎢IOUT⎢ ≤ 20 µA 4.5 5.5 0.8 0.8 0.8 0.8 0.8 0.8 V VOH Minimum HighLevel Output Voltage VIN=VIH or VIL ⎢IOUT⎢ ≤ 20 µA 4.5 5.5 4.4 5.4 4.4 5.4 4.4 5.4 V VIN=VIH or VIL ⎢IOUT⎢ ≤ 4.0 mA 4.5 3.98 3.84 3.7 VIN=VIH or VIL ⎢IOUT⎢ ≤ 20 µA 4.5 5.5 0.1 0.1 0.1 0.1 0.1 0.1 VIN=VIH or VIL ⎢IOUT⎢ ≤ 4.0 mA 4.5 0.26 0.33 0.4 VOL Maximum LowLevel Output Voltage V IIN Maximum Input Leakage Current VIN=VCC or GND 5.5 ±0.1 ±1.0 ±1.0 µA ICC Maximum Quiescent Supply Current (per Package) VIN=VCC or GND IOUT=0µA 5.5 4.0 40 160 µA ∆ICC Additional Quiescent Supply Current VIN = 2.4 V, Any One Input VIN=VCC or GND, Other Inputs ≥-55°C 25°C to 125°C mA 2.9 2.4 IOUT=0µA 5.5 Rev. 00 IN74HCT138A AC ELECTRICAL CHARACTERISTICS (VCC =5.0 V, CL=50pF,Input tr=tf=6.0 ns) Guaranteed Limit Symbol Parameter 25 °C to -55°C ≤85°C ≤125°C Unit tPLH, tPHL Maximum Propagation Delay, Input A to Output Y (Figures 1 and 4) 30 38 45 ns tPLH, tPHL Maximum Propagation Delay , CS1 to Output Y (Figures 2 and 4) 27 34 41 ns tPLH, tPHL Maximum Output Transition Time , CS2 or CS3 to Output Y (Figures 3 and 4) 30 38 45 ns tTLH, tTHL Maximum Output Transition Time, Any Output (Figures 2 and 4) 15 19 22 ns Maximum Input Capacitance 10 10 10 pF CIN CPD Power Dissipation Capacitance (Per Enabled Output) Typical @25°C,VCC=5.0 V Used to determine the no-load dynamic power consumption: PD=CPDVCC2f+ICCVCC 51 Figure 1. Switching Waveforms pF Figure 2. Switching Waveforms Rev. 00 IN74HCT138A Figure 3. Switching Waveforms Figure 4. Test Circuit EXPANDED LOGIC DIAGRAM Rev. 00 IN74HCT138A N SUFFIX PLASTIC DIP (MS - 001BB) A Dimension, mm 9 16 Symbol MIN MAX A 18.67 19.69 B 6.1 7.11 B 1 8 5.33 C F L C D 0.36 0.56 F 1.14 1.78 G 2.54 H 7.62 -T- SEATING PLANE N G K M H D J 0.25 (0.010) M T NOTES: 1. Dimensions “A”, “B” do not include mold flash or protrusions. Maximum mold flash or protrusions 0.25 mm (0.010) per side. J 0° 10° K 2.92 3.81 L 7.62 8.26 M 0.2 0.36 N 0.38 D SUFFIX SOIC (MS - 012AC) Dimension, mm A 16 9 H B 1 G P 8 R x 45 C -TK D SEATING PLANE J 0.25 (0.010) M T C M NOTES: 1. Dimensions A and B do not include mold flash or protrusion. 2. Maximum mold flash or protrusion 0.15 mm (0.006) per side for A; for B ‑ 0.25 mm (0.010) per side. F M Symbol MIN MAX A 9.8 10 B 3.8 4 C 1.35 1.75 D 0.33 0.51 F 0.4 1.27 G 1.27 H 5.72 J 0° 8° K 0.1 0.25 M 0.19 0.25 P 5.8 6.2 R 0.25 0.5 Rev. 00