Overview
The 74F240PC is a classic octal inverting buffer/line driver IC from Fairchild Semiconductor. Featuring high-speed Schottky logic and 3-state (tri-state) outputs, this device is ideal for driving bus lines, buffering memory address registers, and general-purpose digital signal conditioning in industrial control, telecommunications, and data-processing applications. The 74F240PC inverting buffer provides reliable signal inversion and buffering with excellent output drive capability.
Key Features
- 8-channel octal inverting buffer with independent control per channel pair
- 3-state (tri-state) outputs for bus-driving and high-impedance isolation
- High output sink current: 64 mA (commercial) / 48 mA (military)
- Source current: 12 mA for fast rise times and low propagation delay
- Input clamp diodes limit high-speed termination effects
- Guaranteed 4000V minimum ESD protection
- 20-pin PDIP package with DIP rail compatibility
Technical Specifications
- Inverting channels: 8 (organized as four 2-input buffers with shared output enable per pair)
- Output drive: 64 mA sink / 12 mA source (commercial grade)
- Package type: 20-pin PDIP (plastic DIP with rail)
- Logic family: Fast Schottky TTL (74F series)
- Propagation delay: Guaranteed low skew, less than 2.0 ns output skew
- ESD protection: 4000V human body model minimum
Typical Applications
- Bus line drivers and buffers for address/data buses in memory systems
- Clock distribution and buffering in synchronous digital circuits
- Signal inversion and conditioning in logic interfaces
- Legacy microprocessor and microcontroller support circuits
- Industrial control panel logic and PLC analog conditioning circuits
- Telecommunications equipment timing and control logic
Compatibility & Replacements
Compatible With
- TTL and CMOS logic families (5V standard logic systems)
- Memory address bus architectures (Intel, Motorola, and generic 8/16-bit processors)
- Clock distribution systems with 3-state control requirements
- Industrial relay logic and discrete PLC-based control systems
- Breadboard prototyping and embedded design environments
Replaces / Drop-In Replacement For
- 54F240 (military temperature-range variant of the same logic function)
- Earlier generation TTL buffer/drivers (74LS240 with logic changes required)
- Custom discrete inverter/buffer implementations in legacy boards
Works With
- Standard 5V TTL/CMOS logic interfaces
- PCB breadboards and wire-wrap prototyping
- Manual schematic capture and discrete logic design tools
- Generic logic analyzer equipment and digital multimeters
