Overview
The SN74AC14DR is a hex Schmitt-trigger inverter produced by Texas Instruments. This device is part of the 74AC series, known for its high-speed CMOS logic. It features six independent inverting buffers with Schmitt-trigger inputs, which provide hysteresis to improve noise immunity. The device operates over a wide voltage range from 2V to 6V, making it versatile for various digital circuit applications.
Key Specifications
| Parameter | Min | Max | Unit | Conditions | |
|---|---|---|---|---|---|
| VCC Operating Voltage | 2 | 6 | V | ||
| Input Voltage | 0 | 6 | V | ||
| tPLH (Propagation Delay, A to Y) | 1.5 | 5 | 10 | ns | VCC = 5V, TA = 25°C |
| tPHL (Propagation Delay, A to Y) | 1.5 | 5 | 8.5 | ns | VCC = 5V, TA = 25°C |
| Operating Temperature | -40 | 85 | °C | ||
| Low-level Output Current (IOL) | 12 | 24 | mA | VCC = 3V to 5.5V | |
| Junction-to-Ambient Thermal Resistance (RθJA) | 89.9 | °C/W | SOIC Package |
Key Features
- VCC operation from 2V to 6V, allowing for voltage translation from 3.3V to 5V.
- Inputs accept voltages up to 6V, making them tolerant to higher input levels.
- Schmitt-trigger inputs with different threshold levels for positive-going (VT+) and negative-going (VT−) signals, enhancing noise immunity.
- Temperature-compensated circuits that can be triggered from slow input ramps, providing clean and jitter-free output signals.
- Balanced CMOS push-pull outputs capable of sinking and sourcing similar currents.
- Slow edge rates to minimize output ringing.
- Inputs are TTL-voltage compatible.
- Clamp diode structure on inputs and outputs to protect against overvoltage.
Applications
- Synchronizing inverted clock inputs in digital circuits.
- Debouncing switches to eliminate noise and ensure clean signal transitions.
- Inverting digital signals in various logic circuits.
- Bus interface applications where output ringing is a concern, due to the device's low drive and slow edge rates.
- Use in D-type flip-flops, counters, and other sequential logic circuits.
Q & A
- What is the operating voltage range of the SN74AC14DR?
The SN74AC14DR operates over a voltage range from 2V to 6V.
- What is the propagation delay of the SN74AC14DR at 5V?
The propagation delay (tPLH and tPHL) is typically 5ns, with a maximum of 10ns and 8.5ns respectively at 5V and 25°C.
- What are the key benefits of the Schmitt-trigger inputs in the SN74AC14DR?
The Schmitt-trigger inputs provide hysteresis, which improves noise immunity by having different threshold levels for positive-going and negative-going signals.
- What are the typical applications of the SN74AC14DR?
Typical applications include synchronizing inverted clock inputs, debouncing switches, inverting digital signals, and use in bus interface applications where output ringing is a concern.
- What is the maximum low-level output current (IOL) of the SN74AC14DR?
The maximum low-level output current (IOL) is 24 mA at VCC = 5.5V.
- What is the junction-to-ambient thermal resistance (RθJA) for the SOIC package?
The junction-to-ambient thermal resistance (RθJA) for the SOIC package is 89.9°C/W.
- How do the balanced CMOS push-pull outputs of the SN74AC14DR benefit the circuit design?
The balanced CMOS push-pull outputs can sink and source similar currents, which helps in maintaining stable output levels and preventing bus contention.
- What precautions should be taken when using the SN74AC14DR in a circuit?
Precautions include ensuring that load currents do not exceed 35 mA per output, outputs are not pulled above VCC, and routing and load conditions are considered to prevent ringing.
- Is the SN74AC14DR suitable for high-speed applications?
Yes, the SN74AC14DR is suitable for high-speed applications due to its fast propagation delay and ability to handle high-frequency signals.
- What is the significance of the clamp diode structure in the SN74AC14DR?
The clamp diode structure protects the inputs and outputs from overvoltage conditions, ensuring the device's reliability and longevity.
