onsemi MC14584BCP Hex Schmitt Trigger Inverter IC: Datasheet and Application Overview
The onsemi MC14584BCP is a monolithic complementary MOS (CMOS) integrated circuit constructed with N- and P-channel enhancement mode transistors. This IC belongs to a classic family of logic devices and remains highly relevant for its unique signal conditioning capabilities. It contains six independent Schmitt trigger inverters, each functioning as a single-input inverter with the exceptional noise immunity and waveform shaping properties inherent to Schmitt trigger input circuitry.
A defining feature of the MC14584BCP is its hysteresis voltage characteristic. Unlike a standard inverter, which has a single, sharp transition voltage (V~T~), a Schmitt trigger has two distinct threshold voltages: a positive-going threshold (V~T+~) and a negative-going threshold (V~T-~). The difference between these two voltages is the hysteresis (V~H~). This built-in noise margin ensures that a slow-moving or noisy input signal will produce a clean, sharp, jitter-free digital output signal. This makes the IC exceptionally resistant to electrical noise on input lines.
Key Electrical Characteristics
The device operates across a broad voltage range, typically from 3.0V to 18V, making it suitable for both 5V TTL and higher-voltage CMOS systems. Key parameters from the datasheet include:
High Noise Immunity: Typically 45% of the supply voltage at V~DD~ = 10V.
Low Power Consumption: Quiescent current of just 1µA at 25°C, making it ideal for battery-powered applications.
Hysteresis Voltage (V~H~): Typically 0.9V at V~DD~ = 5V and 2.3V at V~DD~ = 10V.
Fanout: Capable of driving up to 50 LS TTL inputs, 74HC, or 74HCT loads.
Primary Applications Overview
The combination of inversion and hysteresis enables a wide array of practical applications:
1. Waveform Squaring: The most common use is to convert sine waves or other analog waveforms into clean, digital square waves. This is essential in clock recovery circuits from noisy sources.
2. Pulse Shaping: It effectively restores degraded or rounded digital pulses to their original sharp, rectangular form.
3. Noise Filtering/Debouncing: A critical application is switch debouncing. The hysteresis prevents a single mechanical switch closure from being interpreted as multiple logic transitions, providing a clean output from a bouncing input.
4. RC Oscillator Circuits: A single Schmitt trigger inverter, a resistor, and a capacitor can form a simple yet highly stable multivibrator oscillator. The frequency of oscillation is determined by the values of R and C. Multiple inverters on the same chip can be used to create complex timing and clock generation circuits.
Package and Configuration
The MC14584BCP is offered in a standard 14-pin plastic dual in-line package (PDIP). The pinout follows a common configuration for hex inverter ICs, with pins 1, 3, 5, 9, 11, and 13 as inputs and pins 2, 4, 6, 8, 10, and 12 as their corresponding inverted outputs. V~DD~ (positive supply) is connected to pin 14, and V~SS~ (ground) is connected to pin 7.
ICGOODFIND: The onsemi MC14584BCP is a versatile and robust solution for signal conditioning tasks. Its integrated hysteresis provides superior noise immunity and reliable operation in electrically noisy environments. Key strengths include its low power consumption, wide operating voltage range, and ability to perform essential functions like waveform squaring, debouncing, and oscillation. It remains a fundamental component for designers looking to interface analog domains with digital logic cleanly and effectively.
Keywords: Schmitt Trigger, Hysteresis, Waveform Shaping, Noise Immunity, Signal Conditioning.
