74373 Octal D-Type Latch with 3-Output State IC

74373 Octal D-Type Transparent Latch with 3-State Outputs

The 74373 is an octal D-type transparent latch with tri-state outputs designed for temporary data storage, buffering and bus interfacing in digital systems. Built in TTL technology, the IC offers high-speed switching, strong noise immunity and compatibility with other TTL devices, making it ideal for microprocessor and microcontroller systems.

Key Features

• 8-bit (octal) D-type transparent latch
• 3-state (tri-state) outputs for bus-oriented applications
• Latch Enable (LE) selects transparent or latched operation
• Output Enable (OE) provides high-impedance (Hi-Z) control for shared buses
• TTL logic family for compatibility with common digital systems
• Capable of driving ±8 mA output currents for typical loads
• Fast propagation delay (typical 20 ns) for high-speed designs
• Standard 20-pin Dual Inline Package (DIP) for easy prototyping and PCB mounting

How the 74373 Works

• When LE (Latch Enable) is HIGH, outputs track the D inputs (transparent mode).
• When LE transitions LOW, the last data present on the D inputs is stored and held (latched mode).
• When OE (Output Enable) is HIGH, outputs are placed in a high-impedance state, allowing multiple devices to share a common bus without contention.
• When OE is LOW, the latched or transparent data is driven to the outputs.

Common Applications

• Microprocessor and microcontroller data buffering
• Bus interfacing and shared-bus systems
• Temporary data storage and register latching
• Memory address latching and I/O port buffering
• Peripheral data holding and timing/synchronization circuits

Specifications

• Type: Octal D-type latch with tri-state outputs
• Logic family: TTL (Transistor-Transistor Logic)
• Supply voltage (VCC): 4.75 V to 5.25 V
• Input High Voltage (VIH): ≥ 2.0 V
• Input Low Voltage (VIL): ≤ 0.8 V
• Output current (IOL/IOH): ±8 mA
• Propagation delay (typical): 20 ns
• Operating temperature: 0°C to +70°C
• Package: 20-pin Dual Inline Package (DIP)

Package, Handling and Integration

The 74373 comes in a standard 20-pin DIP, suitable for breadboards and printed circuit boards. Its TTL compatibility simplifies integration with other TTL devices and legacy systems. Use OE to safely connect multiple devices to a shared data bus and LE to capture or pass data as required by your timing needs.

Note: Images are for illustration purposes only.