MM74HC688WMX is a Identity Comparator by Onsemi, 2V ~ 6V supply voltage, in 20-SOIC (0.295", 7.50mm Width) package, rated for -40°C ~ 85°C. This part is discontinued. FPGACenter specializes in sourcing obsolete components.
MM74HCT688WMX is a Identity Comparator by Rochester Electronics, 4.5V ~ 5.5V supply voltage, in 20-SOIC (0.295", 7.50mm Width) package, rated for -55°C ~ 125°C.
N74F85D,518 is a Magnitude Comparator by NXP Semiconductors, 4.5V ~ 5.5V supply voltage, in 16-SOIC (0.154", 3.90mm Width) package, rated for 0°C ~ 70°C. This part is discontinued. FPGACenter specializes in sourcing obsolete components.