What is CD4093 IC? Pin Diagram, Circuit and Applications

The CD4093 is a CMOS quad two-input NAND gate featuring Schmitt trigger inputs that improve noise immunity and enable reliable switching with slow or noisy input signals. It is widely used in oscillators, debounce circuits, waveform shaping, timing circuits, and digital logic applications.

Key features of CD4093

• Schmitt Trigger Action: Built-in hysteresis on every input, meaning it switches at different voltage points for positive going (Vp) and negative going (Vn) signals without needing external components.
• Infinite Input Rise/Fall Tolerance: There is no limit on input rise and fall times, allowing it to safely process extremely slow changing analog style signals.
• Defined Hysteresis: Hysteresis voltage is typically 0.9 V (at Vdd = 5 V) and 2.3 V (at Vdd = 10 V).
• High Noise Immunity: Noise immunity is greater than 50%, making it highly reliable in electrically noisy environments.
• Automotive Qualified: Meets AEC-Q100 standards for automotive applications.
• Wide Voltage Range: Parametric ratings at 5 V, 10 V, and 15 V, with an absolute maximum operating range up to 18V (20V absolute max).
• Robust ESD Protection: 2000 V Human Body Model (HBM), 1000-V Charge Device Model (CDM), and 200-V Machine Model.
• Standardized Output: Symmetrical output characteristics.

CD4093 Pin Diagram

Pin Number	Pin Name	Description
1	A	Data Input 1 for Gate 1
2	B	Data Input 2 for Gate 1
3	J	NAND Output for Gate 1 ($J = \overline{A \cdot B}$)
4	K	NAND Output for Gate 2 ($K = \overline{C \cdot D}$)
5	C	Data Input 1 for Gate 2
6	D	Data Input 2 for Gate 2
7	$V_{SS}$	Ground / Negative Power Supply
8	E	Data Input 1 for Gate 3
9	F	Data Input 2 for Gate 3
10	L	NAND Output for Gate 3 ($L = \overline{E \cdot F}$)
11	M	NAND Output for Gate 4 ($M = \overline{G \cdot H}$)
12	G	Data Input 1 for Gate 4
13	H	Data Input 2 for Gate 4
14	$V_{DD}$	Positive Power Supply (3V to 18V operating range)

• Reference : CD4093B-Q1 (CMOS Quad 2-Input NAND Schmitt Trigger) datasheet

Example Use Case

• Simple Astable Multivibrator (Clock Oscillator)

Applications of CD4093

• Wave and Pulse Shapers: Squaring up slow, sloppy, or noisy waveforms into crisp digital signals.
• High Noise Environment Systems: Automotive or industrial environments where electrical interference could cause false triggering in standard logic gates.
• Monostable Multivibrators (One-Shots): Generating a pulse of a specific duration.
• Astable Multivibrators: Creating simple clock oscillators.
• Standard NAND Logic: Can be used anywhere a standard quad 2-input NAND gate is required, but with the added benefit of input filtering.

Summary

CD4093 provides four NAND gates with Schmitt trigger inputs, making it ideal for noisy environments and timing applications.