The HD74156P is a high-speed dual 2-to-4 line decoder/demultiplexer manufactured by Hitachi. It's a member of the 7400 series of TTL logic devices, designed for applications requiring data routing and decoding. Each decoder section has two enable inputs (G1 and G2), allowing for flexible control and cascading of multiple devices.

Applications:

• Memory address decoding
• Data routing and selection
• Demultiplexing data from a single line to multiple outputs
• Seven-segment display decoding (with additional components)
• Digital multiplexing and demultiplexing systems

Features:

• Dual 2-to-4 line decoder/demultiplexer
• Two enable inputs (G1 and G2) per decoder section
• High-speed operation
• Low power consumption
• Standard TTL logic levels
• Multiple device cascading capability

Benefits:

• Efficient data routing and selection
• Simplified memory addressing schemes
• Reduced component count in complex digital systems
• Improved system performance due to high-speed operation
• Easy integration with other TTL logic devices

The HD74156P functions by selecting one of its four outputs based on the binary input code applied to its address lines (A0 and A1). When the enable inputs (G1 and G2) are both low, the selected output goes low, while all other outputs remain high. When either enable input is high, all outputs are forced high, effectively disabling the decoder section. This enable functionality allows for easy cascading of multiple HD74156P devices to create larger decoders or demultiplexers.

Technical Specifications:

• Logic Family: TTL
• Number of Decoders: 2
• Decoding Type: 2-to-4 Line
• Enable Inputs: 2 per decoder
• Operating Voltage: 4.75V to 5.25V
• Operating Temperature: 0°C to +70°C
• Package Type: DIP-16