| PartNumber | 74ACT521SC | 74ACT521PC | 74ACT521MTC |
| Description | Logic Comparators 8-Bit Identity Comp | Logic Comparators 8-Bit Identity Comp | Logic Comparators 8-Bit Identity Comp |
| Manufacturer | ON Semiconductor | ON Semiconductor | ON Semiconductor |
| Product Category | Logic Comparators | Logic Comparators | Logic Comparators |
| RoHS | Y | Y | Y |
| Comparator Type | Identity | Identity | Identity |
| Number of Bits | 8 bit | 8 bit | 8 bit |
| Logic Function | A = B | A = B | A = B |
| Output Type | Active Low | Active Low | Active Low |
| Supply Voltage Max | 5.5 V | 5.5 V | 5.5 V |
| Supply Voltage Min | 4.5 V | 4.5 V | 4.5 V |
| Minimum Operating Temperature | - 40 C | - 40 C | - 40 C |
| Maximum Operating Temperature | + 85 C | + 85 C | + 85 C |
| Propagation Delay Time | 10 ns | 10 ns | 10 ns |
| Mounting Style | SMD/SMT | Through Hole | SMD/SMT |
| Package / Case | SOIC-20 | PDIP-20 | TSSOP-20 |
| Packaging | Tube | Tube | Tube |
| Product | Digital Comparators | Digital Comparators | Digital Comparators |
| Brand | ON Semiconductor / Fairchild | ON Semiconductor / Fairchild | ON Semiconductor / Fairchild |
| Input Voltage Range | - 0.5 V to + 0.5 V | - 0.5 V to + 0.5 V | - 0.5 V to + 0.5 V |
| Ib Input Bias Current | 0.004 mA | 0.004 mA | 0.004 mA |
| Operating Supply Voltage | 5 V | 5 V | 5 V |
| Polarity | Inverting | Inverting | Inverting |
| Product Type | Logic Comparators | Logic Comparators | Logic Comparators |
| Factory Pack Quantity | 36 | 18 | 73 |
| Subcategory | Logic ICs | Logic ICs | Logic ICs |
| Part # Aliases | 74ACT521SC_NL | - | - |
| Unit Weight | 0.028254 oz | 0.079719 oz | 0.006737 oz |