Texas Instruments

CD74HCT21M

CD74HCT21M Description

The CD74HCT21M from Texas Instruments is a high-speed dual 4-input AND gate integrated circuit (IC) in the 74HCT series, designed for robust digital logic applications. Housed in a 14-pin SOIC package, this surface-mount device operates within a 4.5V to 5.5V supply range, making it compatible with 5V TTL and CMOS systems. It features a maximum propagation delay of 27ns at 4.5V with a 50pF load, ensuring reliable performance in timing-critical circuits. With low quiescent current (2µA max) and symmetrical output drive (4mA sink/source), it balances power efficiency and signal integrity.

CD74HCT21M Features

• Logic Type: Dual 4-input AND gate (2 circuits).
• High Noise Immunity: HCT technology ensures compatibility with TTL levels (input high: 2V, low: 0.8V).
• Low Power Consumption: 2µA max quiescent current minimizes standby power.
• Robust Output Drive: 4mA output current supports moderate fan-out requirements.
• Wide Operating Voltage: 4.5V–5.5V suits mixed-voltage systems.
• Reliable Packaging: Tube-packed SOIC-14 with MSL1 (unlimited shelf life) for easy handling.
• Compliance: ROHS3 and REACH unaffected, meeting environmental standards.

CD74HCT21M Applications

Ideal for digital systems requiring multi-input logic consolidation, the CD74HCT21M excels in:

• Signal Conditioning: Combining multiple sensor outputs in industrial control systems.
• Address Decoding: Enabling complex memory or peripheral selection in microcontrollers.
• Clock Synchronization: Gating clock signals in timing circuits.
• Error Detection: Implementing parity checks or fault-monitoring logic.
  Its TTL-compatible inputs and CMOS-level efficiency make it a versatile choice for embedded systems, automotive electronics, and test equipment.

Conclusion of CD74HCT21M

The CD74HCT21M stands out for its speed, power efficiency, and compatibility in 5V logic designs. Its dual 4-input AND configuration reduces component count in complex logic networks, while HCT technology bridges TTL and CMOS interfaces. With Texas Instruments' reliability and industry-standard packaging, it is a pragmatic solution for high-noise environments and power-sensitive applications. Engineers can leverage its performance in prototyping, automation, and signal processing with confidence.