Overview
The SN74HC08NSR, produced by Texas Instruments, is a quadruple 2-input AND gate integrated circuit. This device is part of the HC (High-Speed CMOS) logic family and is designed to perform the Boolean function Y = A ● B in positive logic for each of its four independent gates.
It is characterized by its wide operating voltage range of 2 V to 6 V and a temperature range of –40°C to +85°C, making it versatile for various applications. The SN74HC08NSR is available in several package options, including SOIC, SSOP, PDIP, and TSSOP, to suit different design requirements.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC Supply Voltage | –0.5 | 7 | V | |
| Input Clamp Current (IIK) | ±20 | mA | ||
| Output Clamp Current (IOK) | ±20 | mA | ||
| Continuous Output Current (IO) | ±25 | mA | ||
| Junction Temperature (TJ) | 150 | °C | ||
| Storage Temperature (Tstg) | –60 | 150 | °C | |
| Operating Temperature Range | –40 | 85 | °C | |
| Input Leakage Current (II) | ±1 | µA | ||
| Supply Current (ICC) | 20 | µA | ||
| Input Capacitance (Ci) | 10 | pF |
Key Features
- Buffered Inputs: The device features buffered inputs to enhance signal integrity.
- Wide Operating Voltage Range: Operates from 2 V to 6 V, making it suitable for a variety of applications.
- Wide Operating Temperature Range: Functions over a temperature range of –40°C to +85°C.
- High Fanout Capability: Supports fanout up to 10 LSTTL loads.
- Power Reduction: Significant power reduction compared to LSTTL logic ICs.
- Balanced CMOS Push-Pull Outputs: Outputs are capable of sinking and sourcing similar currents, ensuring balanced operation.
- Standard CMOS Inputs: High impedance inputs with low leakage current.
- Clamp Diode Structure: Inputs and outputs have both positive and negative clamping diodes for protection.
Applications
- Combining Power Good Signals: Can be used to combine multiple power good signals into a single output.
- Enable Digital Signals: Useful in enabling or disabling digital signals based on specific conditions.
- Logic Circuits: Ideal for constructing complex logic circuits, such as 4-input AND gates by combining multiple 2-input AND gates.
- General Digital Logic: Suitable for various digital logic applications requiring AND gate functionality.
Q & A
- What is the operating voltage range of the SN74HC08NSR?
The operating voltage range is from 2 V to 6 V.
- What is the temperature range for the SN74HC08NSR?
The device operates over a temperature range of –40°C to +85°C.
- How many independent AND gates does the SN74HC08NSR contain?
The device contains four independent 2-input AND gates.
- What is the maximum continuous output current for the SN74HC08NSR?
The maximum continuous output current is ±25 mA.
- What type of inputs does the SN74HC08NSR have?
The device has standard CMOS inputs with high impedance.
- How should unused inputs be handled on the SN74HC08NSR?
Unused inputs must be held at VCC or GND to ensure proper device operation.
- What is the purpose of the clamping diodes in the SN74HC08NSR?
The clamping diodes protect the inputs and outputs from voltage spikes beyond the specified ratings.
- What is the recommended bypass capacitor for the power supply of the SN74HC08NSR?
A 0.1-μF capacitor is recommended, and it is acceptable to parallel multiple bypass caps to reject different frequencies of noise.
- Can the SN74HC08NSR drive larger capacitive loads?
Yes, but it is recommended to add a series resistor between the output and the capacitor to limit output current and prevent damage.
- What are the implications of slow or floating CMOS inputs on the SN74HC08NSR?
Slow or floating inputs can cause oscillations and excessive current consumption; using a Schmitt-trigger input can help condition the input signal.
