DESCRIPTION
PIN CONNECTION AND IEC LOGIC SYMBOLS June 1999 1/9 74VHC257 INPUT EQUIVALENT CIRCUIT PIN DESCRIPTION
PIN No 1 2, 5, 14, 11 3, 6, 13, 10 4, 7, 12, 9 15 8 16 SYMBOL SELECT 1A to 4A 1B to 4B 1Y to 4Y OE GND VCC NAME AND FUNCT ION Common Data Select Input Data Input From Source A Data Inputs from Source B 3 State Multiplexer Outputs 3 State Output Enable Inputs (Active LOW) Ground (0V) Positive Supply Voltage TRUTH TABLE INPUT S OE H L L L L X = DON’T CARE Z = HIGH IMPEDANCE OUTPUTS A X L H X X B X X X L H Y Z L H L H SELE CT X L L H H LOGIC DIAGRAM Thislogic diagram has notbe used to estimate propagation delays 2/9 74VHC257 ABSOLUTE MAXIMUM RATINGS
Symbol VCC VI VO IIK IOK IO Tstg TL Supply Voltage DC Input Voltage DC Output Voltage DC Input Diode Current DC Output Diode Current DC Output Current Storage Temperature Lead Temperature (10 sec) Parameter Value -0.5 to +7.0 -0.5 to +7.0 -0.5 to VCC + 0.5 - 20 ± 20 ± 25 ± 50 -65 to +150 300 Unit V V V mA mA mA mA o o ICC or IGND DC VCC or Ground Current C C ABSOLUTE MAXIMUM RATINGS
are those values beyond which damage to the device may occur.
STMicroelectronics
