DESCRIPTION
The internal circuit is composed of 3 stages (2INPUT) or 5 stages (3-INPUT) including buffered output, which gives high noise immunity and a stable output. All inputs are equipped with protection circuits against static discharge and transient excess voltage. INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN CONNECTIONS (top view) NC = No Internal Connection December 1992 1/9 M54/M74HC51 PIN DESCRIPTION
PIN No 1, 12, 13, 9, 10, 11 2, 3, 4, 5 8, 6 7 14 SYMBOL 1A to 1F 2A to 2D 1Y, 2Y GND VCC NAME AND FUNCTION Data Inputs Data Inputs Data Outputs Ground (0V) Positive Supply Voltage IEC LOGIC SYMBOL TRUTH TABLE 1A H X 1B 1C 1D 1E H H X X X X H H ALL OTHER COMBINATIONS 1F X H 1Y L L H TRUTH TABLE 2A H X 2B 2C 2D H X X X H H ALL OTHER COMBINATIONS 2Y L L H X = DON’T CARE LOGIC DIAGRAM ABSOLUTE MAXIMUM RATINGS
Symbol VCC VI VO IIK IOK IO ICC or IGND PD Tstg TL Parameter Supply Voltage DC Input Voltage DC Output Voltage DC Input Diode Current DC Output Diode Current DC Output Source Sink Cu...
STMicroelectronics
