onsemi MC14584BDR2G Hex Schmitt Trigger IC: Datasheet, Application Circuit, and Pinout Configuration
The onsemi MC14584BDR2G is a highly reliable integrated circuit belonging to the CD4000 series, renowned for its robustness and wide operating voltage range. This IC is a hex inverting Schmitt trigger, meaning it contains six independent inverters within a single 14-pin package. Each gate incorporates Schmitt trigger technology at its input, which provides hysteresis—a critical feature that drastically improves noise immunity and converts slowly changing or noisy input signals into clean, sharp digital output waveforms. This makes the MC14584BDR2G an indispensable component for signal conditioning, waveform shaping, and bounce elimination in switch inputs.
Pinout Configuration
The MC14584BDR2G is housed in a standard SOIC-14 package. The pinout is logically arranged, with the six inverters utilizing most of the available pins.
Pins 1, 3, 5, 9, 11, 13: These are the inputs (A) for the six individual Schmitt trigger inverters (Input 1 through Input 6).
Pins 2, 4, 6, 8, 10, 12: These are the corresponding outputs (Y) for each inverter (Output 1 through Output 6).
Pin 7: Ground (VSS). This pin must be connected to the negative supply rail or ground.
Pin 14: Positive Supply (VDD). This pin is connected to the positive voltage supply, which can range from 3.0V to 18V, offering great flexibility for various logic level systems.
Datasheet Overview and Key Specifications
The manufacturer's datasheet provides all necessary information for designing the IC into a circuit. Key absolute maximum ratings and electrical characteristics include:
Supply Voltage Range (VDD): 3.0 V to 18 V
High-Level Output Voltage (VOH): Typically 4.95V (at VDD=5V, IOH=-0.44mA)
Low-Level Output Voltage (VOL): Typically 0.05V (at VDD=5V, IOL=0.44mA)
Hysteresis (ΔVT): A defining feature. The typical positive-going threshold voltage (VT+) is higher than the negative-going threshold voltage (VT-). For example, at a VDD of 5V, VT+ is approximately 3.0V and VT- is 2.2V, resulting in a typical hysteresis of 0.8V.
Operating Temperature Range: -55°C to +125°C, making it suitable for industrial and automotive applications.
Application Circuit: Debouncing a Mechanical Switch
One of the most common uses for a Schmitt trigger like the MC14584BDR2G is to eliminate switch bounce. The inherent hysteresis cleans up the erratic signal generated when a mechanical switch is pressed or released.
Circuit Setup:
1. Connect VDD (Pin 14) to a positive supply voltage (e.g., 5V).
2. Connect VSS (Pin 7) to ground.
3. Connect a mechanical pushbutton switch between VDD and one of the inverter inputs (e.g., Pin 1).
4. Connect a pull-down resistor (e.g., 10kΩ) between the same input (Pin 1) and ground (VSS). This ensures the input is pulled to a defined low logic level when the switch is open.
5. The corresponding output (Pin 2) will provide a clean, bounce-free digital signal. When the switch is pressed, the output goes from high to low without any oscillating pulses, and vice-versa.
This clean output can then be fed directly into a microcontroller or other digital logic input, ensuring reliable and error-free operation.
The onsemi MC14584BDR2G stands as a fundamental solution for managing imperfect digital signals. Its built-in hysteresis, wide voltage operation, and hex inverter configuration provide designers with a simple, effective, and cost-efficient method for signal conditioning, noise rejection, and switch debouncing across a vast array of electronic applications.
Keywords: Schmitt Trigger, Signal Conditioning, Hysteresis, Switch Debouncing, SOIC-14
