M74HC251 8-CHANNEL MULTIPLEXER (3-STATE) HIGH SPEED : t = 17 ns (TYP.) at V = 6V PD CC LOW POWER DISSIPATION: I =4A(MAX.) at T =25C CC A HIGH NOISE IMMUNITY: V = V = 28 % V (MIN.) NIH NIL CC DIP SOP TSSOP SYMMETRICAL OUTPUT IMPEDANCE: I = I = 4mA (MIN) OH OL BALANCED PROPAGATION DELAYS: t t ORDER CODES PLH PHL WIDE OPERATING VOLTAGE RANGE: PACKAGE TUBE T & R V (OPR) = 2V to 6V CC DIP M74HC251B1R 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 2 fabricated with silicon gate C MOS 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 1/11M74HC251 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- 6W 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 YW CBA S XXX H Z Z LLLL D0 D0 L L H L D1 D1 LHL L D2 D2 LH HL D3 D3 H L L L D4 D4 HLHL D5 D5 H H L L D6 D6 HHH L D7 D7 X : Dont Care Z : High Impedance 2/11