1. MM74HCT04MTC Substitution Conclusion A detailed comparison confirms that the MM74HCT04MTC can serve as a direct, pin-to-pin and function-to-function compatible substitute for the SN74HCT04PW in the vast majority of applications. The core logic specifications (hex inverter), supply voltage range (4.5V to 5.5V), input threshold levels (Vil=0.8V, Vih=2V), and package (14-TSSOP) are identical between the two devices. Two minor differences were identified. First, the MM74HCT04MTC's output drive current (4.8mA) is slightly higher than that of the original part (4mA). This provides marginally better fan-out capability or a lower output voltage drop when driving equivalent loads, which is a beneficial characteristic. Second, the maximum propagation delay for the MM74HCT04MTC is specified as 20ns under 5V/50pF conditions, compared to 18ns for the SN74HCT04PW under 5.5V/50pF. Given the slight difference in test voltage and the mere 2ns absolute delay delta, this variation has a negligible impact on timing margins in typical digital logic circuits and will not affect the functionality of most low-to-mid-speed designs. Therefore, this substitution is considered viable for all circuits except those operating at extreme high speeds or with stringent delay matching requirements. It is recommended to perform final validation on the actual target board before proceeding with volume replacement.