Overview
The SN74HC21DR, produced by Texas Instruments, is a dual 4-input AND gate integrated circuit. This device contains two independent AND gates, each performing the Boolean function Y = A ● B ● C ● D in positive logic. It is part of the 74HC series, known for its high-speed CMOS logic and low power consumption.
The SN74HC21DR is available in a 14-pin SOIC package and operates over a wide voltage range of 2 V to 6 V and a temperature range of -40°C to 85°C, making it versatile for various digital logic applications.
Key Specifications
| Parameter | Min | Nom | Max | Unit |
|---|---|---|---|---|
| Supply Voltage (VCC) | 2 | 5 | 6 | V |
| Operating Temperature Range | -40 | 85 | °C | |
| High-Level Input Voltage (VIH) | 1.5 (VCC=2V) | 3.15 (VCC=4.5V) | 4.2 (VCC=6V) | V |
| Low-Level Input Voltage (VIL) | 0.5 (VCC=2V) | 1.35 (VCC=4.5V) | 1.8 (VCC=6V) | V |
| Quiescent Supply Current (ICC) | 20 | µA | ||
| Output High/Low Current | 5.2 | mA | ||
| Propagation Delay (tpd) | 11 (VCC=6V) | 19 (VCC=6V) | 24 (VCC=6V) | ns |
| Input Transition Time | 10 (VCC=6V) | 15 (VCC=6V) | 19 (VCC=6V) | ns |
Key Features
- Buffered Inputs: Ensures stable input signals.
- Wide Operating Voltage Range: 2 V to 6 V, making it compatible with various power supply systems.
- Wide Operating Temperature Range: -40°C to 85°C, suitable for a broad range of environmental conditions.
- High Fanout Capability: Supports up to 10 LSTTL loads.
- Low Power Consumption: Significant power reduction compared to LSTTL logic ICs.
- Balanced CMOS Push-Pull Outputs: Allows the device to sink and source similar currents, ensuring balanced output performance.
Applications
- Combining Power Good Signals: Useful in power management systems where multiple signals need to be combined.
- Enable Digital Signals: Can be used to enable or disable digital signals based on multiple input conditions.
- General Digital Logic Circuits: Suitable for various digital logic applications requiring AND gate functionality.
Q & A
- What is the function of the SN74HC21DR?
The SN74HC21DR contains two independent 4-input AND gates, each performing the Boolean function Y = A ● B ● C ● D in positive logic.
- What is the operating voltage range of the SN74HC21DR?
The operating voltage range is from 2 V to 6 V.
- What is the operating temperature range of the SN74HC21DR?
The operating temperature range is from -40°C to 85°C.
- What is the maximum propagation delay of the SN74HC21DR at 6 V?
The maximum propagation delay at 6 V is 24 ns.
- How many LSTTL loads can the SN74HC21DR support?
The device supports up to 10 LSTTL loads.
- What is the quiescent supply current of the SN74HC21DR?
The quiescent supply current is typically up to 20 µA.
- What is the package type of the SN74HC21DR?
The SN74HC21DR is available in a 14-pin SOIC package.
- Is the SN74HC21DR RoHS compliant?
- What are the typical applications of the SN74HC21DR?
- What is the input transition time of the SN74HC21DR at 6 V?
- Can the SN74HC21DR drive larger currents?
