M74HCT138 3 TO 8 LINE DECODER (INVERTING) ■ ■ ■ ■ ■ ■ HIGH SPEED: tPD = 16ns (TYP.) at VCC = 4.5V LOW POWER DISSIPATION: ICC = 4µA(MAX.) at TA=25°C COMPATIBLE WITH TTL OUTPUTS : VIH = 2V (MIN.) VIL = 0.8V (MAX) SYMMETRICAL OUTPUT IMPEDANCE: |IOH| = IOL = 4mA (MIN) BALANCED PROPAGATION DELAYS: tPLH ≅ tPHL PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 138 DESCRIPTION The M74HCT138 is an high speed CMOS 3 TO 8 LINE DECODER fabricated with silicon gate C2MOS technology. If the device is enabled, 3 binary select inputs (A, B, and C) determine which one of the outputs will go low. If enable input G1 is held low or either G2A or G2B is held high, the decoding function is inhibited and all the 8 outputs go high. Three DIP SOP TSSOP ORDER CODES PACKAGE TUBE DIP SOP TSSOP M74HCT138B1R M74HCT138M1R T&R M74HCT138RM13TR M74HCT138TTR enable inputs are provided to ease cascade connection and application of address decoders for memory systems. All inputs are equipped with protection circuits against static discharge and transient excess voltage. PIN CONNECTION AND IEC LOGIC SYMBOLS August 2001 1/9 M74HCT138 INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN DESCRIPTION PIN No SYMBOL 1, 2, 3 4, 5 6 9, 10, 11, 12, 13, 14, 15, 7 8 16 A, B, C G2A, G2B G1 Y0 to Y7 GND VCC NAME AND FUNCTION Address Inputs Enable Inputs Enable Input Data Outputs Ground (0V) Positive Supply Voltage TRUTH TABLE INPUTS OUTPUTS ENABLE SELECT G2B G2A G1 C B A Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 X X H L L L L L L L L X H X L L L L L L L L L X X H H H H H H H H X X X L L L L H H H H X X X L L H H L L H H X X X L H L H L H L 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 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 X : Don’t Care LOGIC DIAGRAM This logic diagram has not be used to estimate propagation delays 2/9 M74HCT138 ABSOLUTE MAXIMUM RATINGS Symbol VCC Parameter Value Supply Voltage Unit -0.5 to +7 V -0.5 to VCC + 0.5 -0.5 to VCC + 0.5 V DC Input Diode Current ± 20 mA IOK DC Output Diode Current ± 20 mA IO DC Output Current ± 25 mA ± 50 mA VI DC Input Voltage VO DC Output Voltage IIK ICC or IGND DC VCC or Ground Current PD Power Dissipation Tstg Storage Temperature TL Lead Temperature (10 sec) V 500(*) mW -65 to +150 °C 300 °C Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is not implied (*) 500mW at 65 °C; derate to 300mW by 10mW/°C from 65°C to 85°C RECOMMENDED OPERATING CONDITIONS Symbol VCC Parameter Value Unit Supply Voltage 4.5 to 5.5 V VI Input Voltage 0 to VCC V VO Output Voltage 0 to VCC V Top Operating Temperature -55 to 125 °C tr, tf Input Rise and Fall Time (VCC = 4.5 to 5.5V) 0 to 500 ns DC SPECIFICATIONS Test Condition Symbol VIH VIL VOH VOL II ICC ∆ ICC Parameter High Level Input Voltage Low Level Input Voltage Min. 4.5 to 5.5 4.5 to 5.5 4.5 Low Level Output Voltage 4.5 Input Leakage Current Quiescent Supply Current Additional Worst Case Supply Current TA = 25°C VCC (V) High Level Output Voltage Value Typ. Max. 2.0 -40 to 85°C -55 to 125°C Min. Min. Max. 2.0 0.8 Max. 2.0 0.8 V 0.8 IO=-20 µA 4.4 4.5 4.4 4.4 IO=-4.0 mA 4.18 4.31 4.13 4.10 Unit V V IO=20 µA 0.0 0.1 0.1 0.1 IO=4.0 mA 0.17 0.26 0.33 0.40 V 5.5 VI = VCC or GND ± 0.1 ±1 ±1 µA 5.5 VI = VCC or GND 4 40 80 µA 5.5 Per Input pin VI = 0.5V or VI = 2.4V Other Inputs at VCC or GND IO = 0 2.0 2.9 3.0 mA 3/9 M74HCT138 AC ELECTRICAL CHARACTERISTICS (CL = 50 pF, Input tr = tf = 6ns) Test Condition Symbol Parameter tTLH tTHL Output Transition Time tPLH tPHL Propagation Delay Time (A, B, C - Y) tPLH tPHL Propagation Delay Time (G1 - Y) tPLH tPHL Propagation Delay Time (G2 - Y) Value TA = 25°C VCC (V) Min. -40 to 85°C -55 to 125°C Min. Min. Max. Unit Typ. Max. Max. 4.5 8 15 19 22 ns 4.5 17 30 38 45 ns 4.5 16 30 38 45 ns 4.5 19 30 38 45 ns CAPACITIVE CHARACTERISTICS Test Condition Symbol Parameter VCC (V) Value TA = 25°C Min. Typ. Max. 10 CIN Input Capacitance 5 CPD Power Dissipation Capacitance (note 1) 52 -40 to 85°C -55 to 125°C Min. Min. Max. 10 Unit Max. 10 pF pF 1) CPD is defined as the value of the IC’s internal equivalent capacitance which is calculated from the operating current consumption without load. (Refer to Test Circuit). Average operating current can be obtained by the following equation. ICC(opr) = CPD x VCC x fIN + ICC TEST CIRCUIT CL = 50pF or equivalent (includes jig and probe capacitance) RT = ZOUT of pulse generator (typically 50Ω) 4/9 M74HCT138 WAVEFORM 1: PROPAGATION DELAYS FOR INVERTING OUTPUTS (f=1MHz; 50% duty cycle) WAVEFORM 2: PROPAGATION DELAYS FOR NON-INVERTING OUTPUTS (f=1MHz; 50% duty cycle) 5/9 M74HCT138 Plastic DIP-16 (0.25) MECHANICAL DATA mm. inch DIM. MIN. a1 0.51 B 0.77 TYP MAX. MIN. TYP. MAX. 0.020 1.65 0.030 0.065 b 0.5 0.020 b1 0.25 0.010 D 20 0.787 E 8.5 0.335 e 2.54 0.100 e3 17.78 0.700 F 7.1 0.280 I 5.1 0.201 L Z 3.3 0.130 1.27 0.050 P001C 6/9 M74HCT138 SO-16 MECHANICAL DATA DIM. mm. MIN. TYP A a1 inch MAX. MIN. TYP. 1.75 0.1 0.068 0.2 a2 MAX. 0.003 0.007 1.65 0.064 b 0.35 0.46 0.013 0.018 b1 0.19 0.25 0.007 0.010 C 0.5 0.019 c1 45° (typ.) D 9.8 10 0.385 0.393 E 5.8 6.2 0.228 0.244 e 1.27 0.050 e3 8.89 0.350 F 3.8 4.0 0.149 0.157 G 4.6 5.3 0.181 0.208 L 0.5 1.27 0.019 0.050 M S 0.62 0.024 8° (max.) PO13H 7/9 M74HCT138 TSSOP16 MECHANICAL DATA mm. inch DIM. MIN. TYP A MAX. MIN. TYP. MAX. 1.2 A1 0.05 A2 0.8 b 0.047 0.15 0.002 0.004 0.006 1.05 0.031 0.039 0.041 0.19 0.30 0.007 0.012 c 0.09 0.20 0.004 0.0089 D 4.9 5 5.1 0.193 0.197 0.201 E 6.2 6.4 6.6 0.244 0.252 0.260 E1 4.3 4.4 4.48 0.169 0.173 0.176 1 e 0.65 BSC K 0° L 0.45 A 0.60 0.0256 BSC 8° 0° 0.75 0.018 8° 0.024 0.030 A2 A1 b e K c L E D E1 PIN 1 IDENTIFICATION 1 0080338D 8/9 M74HCT138 Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. 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