M74HC251 8-CHANNEL MULTIPLEXER (3-STATE) n HIGH SPEED : t = 17 ns (TYP.) at V = 6V PD CC n LOW POWER DISSIPATION: I =4m A(MAX.) at T =25°C CC A n HIGH NOISE IMMUNITY: V = V = 28 % V (MIN.) NIH NIL CC n SYMMETRICAL OUTPUT IMPEDANCE: DIP SOP TSSOP |I | = I = 4mA (MIN) OH OL n BALANCED PROPAGATION DELAYS: tPLH @ tPHL ORDER CODES n WIDE OPERATING VOLTAGE RANGE: PACKAGE TUBE T & R V (OPR) = 2V to 6V CC DIP M74HC251B1R n PIN AND FUNCTION COMPATIBLE WITH SOP M74HC251M1R M74HC251RM13TR 74 SERIES 251 TSSOP M74HC251TTR DESCRIPTION The M74HC251 is an high speed CMOS in the high impedance state. When enabled, 8-CHANNEL MULTIPLEXER (3-STATE) address information on the data select inputs fabricated with silicon gate C2MOS technology. determines which data input is routed to Y and W. This Multiplexer features both true (Y) and All inputs are equipped with protection circuits complement (W) outputs as well as STROBE against static discharge and transient excess input. When the STROBE is high, both outputs are voltage. PIN CONNECTION AND IEC LOGIC SYMBOLS July 2001 1/11

M74HC251 INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN DESCRIPTION PIN No SYMBOL NAME AND FUNCTION 4, 3, 2, 1, 15, D0 to D7 Multiplexer Inputs 14, 13, 12 5 Y Multiplexer Output Complementary Multi- 6 W plexer Output 3 State Output Enable 7 STROBE Input 11, 10, 9 A, B, C Select Inputs 8 GND Ground (0V) 16 Vcc Positive Supply Voltage TRUTH TABLE INPUTS OUTPUTS STROBE Y W C B A S X X X H Z Z L L L L D0 D0 L L H L D1 D1 L H L L D2 D2 L H H L D3 D3 H L L L D4 D4 H L H L D5 D5 H H L L D6 D6 H H H L D7 D7 X : Don’t Care Z : High Impedance 2/11

M74HC251 LOGIC DIAGRAM This logic diagram has not be used to estimate propagation delays ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit VCC Supply Voltage -0.5 to +7 V VI DC Input Voltage -0.5 to VCC + 0.5 V VO DC Output Voltage -0.5 to VCC + 0.5 V IIK DC Input Diode Current – 20 mA IOK DC Output Diode Current – 20 mA IO DC Output Current – 25 mA ICC or IGND DC VCC or Ground Current – 50 mA PD Power Dissipation 500(*) mW Tstg Storage Temperature -65 to +150 °C TL Lead Temperature (10 sec) 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 (cid:176) C; derate to 300mW by 10mW/(cid:176) C from 65(cid:176) C to 85(cid:176) C 3/11

M74HC251 RECOMMENDED OPERATING CONDITIONS Symbol Parameter Value Unit VCC Supply Voltage 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 VCC = 2.0V 0 to 1000 ns tr, tf VCC = 4.5V 0 to 500 ns VCC = 6.0V 0 to 400 ns DC SPECIFICATIONS Test Condition Value Symbol Parameter V TA = 25°C -40 to 85°C -55 to 125°C Unit CC (V) Min. Typ. Max. Min. Max. Min. Max. V High Level Input 2.0 1.5 1.5 1.5 IH Voltage 4.5 3.15 3.15 3.15 V 6.0 4.2 4.2 4.2 V Low Level Input 2.0 0.5 0.5 0.5 IL Voltage 4.5 1.35 1.35 1.35 V 6.0 1.8 1.8 1.8 VOH High Level Output 2.0 IO=-20 m A 1.9 2.0 1.9 1.9 Voltage 4.5 IO=-20 m A 4.4 4.5 4.4 4.4 6.0 IO=-20 m A 5.9 6.0 5.9 5.9 V 4.5 IO=-4.0 mA 4.18 4.31 4.13 4.10 6.0 IO=-5.2 mA 5.68 5.8 5.63 5.60 VOL Low Level Output 2.0 IO=20 m A 0.0 0.1 0.1 0.1 Voltage 4.5 IO=20 m A 0.0 0.1 0.1 0.1 6.0 IO=20 m A 0.0 0.1 0.1 0.1 V 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 I Input Leakage I Current 6.0 VI = VCC or GND – 0.1 – 1 – 1 m A I High Impedance OZ V = V or V Output Leakage 6.0 I IH IL – 0.5 – 5 – 10 m A V = V or GND Current O CC I Quiescent Supply CC Current 6.0 VI = VCC or GND 4 40 80 m A 4/11

M74HC251 AC ELECTRICAL CHARACTERISTICS (C = 50 pF, Input t = t = 6ns) L r f Test Condition Value Symbol Parameter V TA = 25°C -40 to 85°C -55 to 125°C Unit CC (V) Min. Typ. Max. Min. Max. Min. Max. t t Output Transition 2.0 30 75 95 115 TLH THL Time 4.5 8 15 19 23 ns 6.0 7 13 16 20 t t Propagation Delay 2.0 64 130 165 195 PLH PHL Time 4.5 16 26 33 39 ns (D - Y, W) 6.0 14 22 28 33 t Propagation Delay 2.0 80 160 200 240 PHL Time 4.5 20 32 40 48 ns (A, B, C -Y, W) 6.0 17 27 34 41 t t High Impedance 2.0 36 90 115 135 PZL PZH Output Enable 4.5 R = 1 KW 11 18 23 27 ns L Time 6.0 9 15 20 23 t t High Impedance 2.0 26 85 105 130 PLZ PHZ Output Disable 4.5 R = 1 KW 13 17 21 26 ns L Time 6.0 11 14 18 22 CAPACITIVE CHARACTERISTICS Test Condition Value Symbol Parameter V TA = 25°C -40 to 85°C -55 to 125°C Unit CC (V) Min. Typ. Max. Min. Max. Min. Max. CIN Input Capacitance 5.0 5 10 10 10 pF C Power Dissipation PD Capacitance (note 5.0 62 pF 1) 1) C is defined as the value of the IC’s internal equivalent capacitance which is calculated from the operating current consumption without PD load. (Refer to Test Circuit). Average operating current can be obtained by the following equation. I = C x V x f + I CC(opr) PD CC IN CC 5/11

M74HC251 TEST CIRCUIT TEST SWITCH tPLH, tPHL Open t , t V PZL PLZ CC t , t GND PZH PHZ C = 50pF/150pF or equivalent (includes jig and probe capacitance) RL = 1KW or equivalent 1 R = Z of pulse generator (typically 50W ) T OUT WAVEFORM 1: PROPAGATION DELAY TIME (f=1MHz; 50% duty cycle) 6/11

M74HC251 WAVEFORM 2 : OUTPUT ENABLE AND DISABLE TIME (f=1MHz; 50% duty cycle) 7/11

M74HC251 Plastic DIP-16 (0.25) MECHANICAL DATA mm. inch DIM. MIN. TYP MAX. MIN. TYP. MAX. a1 0.51 0.020 B 0.77 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 3.3 0.130 Z 1.27 0.050 P001C 8/11

M74HC251 SO-16 MECHANICAL DATA mm. inch DIM. MIN. TYP MAX. MIN. TYP. MAX. A 1.75 0.068 a1 0.1 0.2 0.003 0.007 a2 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 0.62 0.024 S 8° (max.) PO13H 9/11

M74HC251 TSSOP16 MECHANICAL DATA mm. inch DIM. MIN. TYP MAX. MIN. TYP. MAX. A 1.2 0.047 A1 0.05 0.15 0.002 0.004 0.006 A2 0.8 1 1.05 0.031 0.039 0.041 b 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 e 0.65 BSC 0.0256 BSC K 0° 8° 0° 8° L 0.45 0.60 0.75 0.018 0.024 0.030 A A2 K L A1 b e c E D E1 PIN 1 IDENTIFICATION 1 0080338D 10/11

M74HC251 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. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. © The ST logo is a registered trademark of STMicroelectronics © 2001 STMicroelectronics - Printed in Italy - All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Brazil - China - Finland - France - Germany - Hong Kong - India - Italy - Japan - Malaysia - Malta - Morocco Singapore - Spain - Sweden - Switzerland - United Kingdom © http://www.st.com 11/11