Catalog > Semiconductors > Integrated Circuits Buffer Buffer 7439 Quad 2-Input NAND Buffer with Open Collector Outputs (Input and Output Terminals Flipped) 20.46 ZAR inc for 1 Each 34 in Stock Add Specifications, Prices & Availability may change without notice. Images are for illustration purposes only. E&OE Features Function: Quad 2-input NAND buffer. Output Type: Open collector, which requires pull-up resistors for proper operation. Applications: Open collector outputs allow for connecting to other similar outputs to implement active-low wired-OR or active-high wired-AND functions. Voltage Levels: Often used to generate higher VOHcap V sub cap O cap H end-sub𝑉𝑂𝐻 (Voltage Output High) levels. Logic Family: Part of the 7400 series TTL logic family.