Catalog > Semiconductors > Integrated Circuits 74LS28 IC Buffer NOR Quad 2-Input 14PD Part No: 74LS28 3.83 ZAR inc for 1 Each (Quoting) Add to Cart Specifications, Prices & Availability may change without notice. Images are for illustration purposes only. E&OE Specifications Logic Type: Quad 2-Input Positive-NOR Buffer Operating Voltage: 4.75V to 5.25V DC (Nominal 5V) Maximum Output Current (Sink): 24 mA Propagation Delay: Typically around 15 ns Operating Temperature: 0°C to +70°C (Commercial) or -55°C to +125°C