M74HC238 3 TO 8 LINE DECODER ■ ■ ■ ■ ■ ■ ■ HIGH SPEED: tPD = 15ns (TYP.) at VCC = 6V LOW POWER DISSIPATION: ICC = 4µA(MAX.) at TA=25°C HIGH NOISE IMMUNITY: VNIH = V NIL = 28 % VCC (MIN.) SYMMETRICAL OUTPUT IMPEDANCE: |IOH| = IOL = 4mA (MIN) BALANCED PROPAGATION DELAYS: tPLH ≅ tPHL WIDE OPERATING VOLTAGE RANGE: VCC (OPR) = 2V to 6V PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 238 DESCRIPTION The M74HC238 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 outputs will go high. When enable input G1 is held "Low" or either G2A or G2B is held "High" decoding function is DIP SOP TSSOP ORDER CODES PACKAGE TUBE DIP SOP TSSOP M74HC238B1R M74HC238M1R T&R M74HC238RM13TR M74HC238TTR inhibited and all the 8 outputs go low. Three enable inputs are provided to ease cascade connection and application of this address decoder in memory systems. All inputs are equipped with protection circuits against static discharge and transient excess voltage. PIN CONNECTION AND IEC LOGIC SYMBOLS July 2001 1/10 M74HC238 INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN DESCRIPTION PIN No SYMBOL NAME AND FUNCTION 1, 2, 3 4, 5 A, B, C G2A G2B 6 G1 15, 14, 13, 12, 11, 10, 9, 7 8 16 Y0 to Y7 Data Inputs Enable Input (Active LOW) Data Enable Input (Active HIGH) Outputs GND VCC Ground (0V) Positive Supply Voltage TRUTH TABLE INPUTS OUTPUTS ENABLE SELECTED OUTPUT 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 L L L H L L L L L L L L L L L H L L L L L L L L L L L H L L L L L L L L L L L H L L L L L L L L L L L H L L L L L L L L L L L H L L L L L L L L L L L H L L L L L L L L L L L H X : Don’t Care LOGIC DIAGRAM This logic diagram has not be used to estimate propagation delays 2/10 NONE NONE NONE Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 M74HC238 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 Supply Voltage Unit 2 to 6 V VI Input Voltage 0 to VCC V VO Output Voltage 0 to VCC V Top Operating Temperature -55 to 125 °C Input Rise and Fall Time tr, tf VCC = 2.0V 0 to 1000 ns VCC = 4.5V 0 to 500 ns VCC = 6.0V 0 to 400 ns 3/10 M74HC238 DC SPECIFICATIONS Test Conditions Symbol VIH VIL VOH VOL II ICC Parameter High Level Input Voltage Low Level Input Voltage High Level Output Voltage Low Level Output Voltage Input Leakage Current Quiescent Supply Current Value TA = 25°C VCC (V) Min. 2.0 4.5 6.0 2.0 4.5 6.0 Typ. Max. 1.5 3.15 4.2 -40 to 85°C -55 to 125°C Min. Min. Max. 1.5 3.15 4.2 0.5 1.35 1.8 Max. 1.5 3.15 4.2 0.5 1.35 1.8 V 0.5 1.35 1.8 2.0 IO=-20 µA 1.9 2.0 1.9 1.9 4.5 IO=-20 µA 4.4 4.5 4.4 4.4 6.0 IO=-20 µA 5.9 6.0 5.9 5.9 4.5 IO=-4.0 mA 4.18 4.31 4.13 4.10 5.68 Unit V V 6.0 IO=-5.2 mA 2.0 IO=20 µA 0.0 0.1 0.1 0.1 4.5 IO=20 µA 0.0 0.1 0.1 0.1 6.0 IO=20 µA 0.0 0.1 0.1 0.1 4.5 IO=4.0 mA 0.17 0.26 0.33 0.40 6.0 IO=5.2 mA 0.18 0.26 0.33 0.40 6.0 VI = VCC or GND ± 0.1 ±1 ±1 µA 6.0 VI = VCC or GND 4 40 80 µA 5.8 5.63 5.60 V AC ELECTRICAL CHARACTERISTICS (CL = 50 pF, Input tr = tf = 6ns) Test Conditions 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) 4/10 VCC (V) 2.0 4.5 6.0 2.0 4.5 6.0 2.0 4.5 6.0 2.0 4.5 6.0 Value TA = 25°C Min. Typ. Max. 30 8 7 50 17 15 50 17 15 50 17 15 75 15 13 150 30 26 150 30 26 150 30 26 -40 to 85°C -55 to 125°C Min. Min. Max. 95 19 16 190 38 32 190 38 32 190 38 32 Unit Max. 110 22 19 225 45 38 225 45 38 225 45 38 ns ns ns ns M74HC238 CAPACITIVE CHARACTERISTICS Test Conditions Symbol Parameter VCC (V) Value TA = 25°C Min. Typ. Max. 10 CIN Input Capacitance 5.0 5 CPD Power Dissipation Capacitance (note 1) 5.0 53 -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) 5/10 M74HC238 WAVEFORM 1: PROPAGATION DELAY TIMES (f=1MHz; 50% duty cycle) 6/10 M74HC238 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 7/10 M74HC238 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 8/10 M74HC238 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 9/10 M74HC238 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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