74LS85 Comparator Integrated Circuit — 4‑Bit TTL Magnitude Comparator (DIP‑16)

The 74LS85 is a 4‑bit magnitude comparator IC from the reliable 74LS TTL logic family. Packaged in a DIP‑16 through‑hole format, it performs fast digital comparison of two binary or BCD words and can be easily cascaded for wider word lengths. Ideal for Arduino, Raspberry Pi (with level shifting), and general microcontroller projects, as well as professional digital logic designs.

⚙️ Key Features

• 4‑bit magnitude comparator for A vs. B comparisons (A>B, A=B, A
• Compares two 4‑bit binary or BCD words with deterministic logic outputs
• TTL‑compatible I/O for direct interface with other 74xx/TTL logic families
• High‑speed performance with low propagation delay (see specs)
• Low power consumption characteristic of LS‑TTL technology
• Cascading support via dedicated cascade inputs/outputs to build 8‑, 12‑, or 16‑bit comparators
• DIP‑16 through‑hole package for easy prototyping and breadboarding

📐 Technical Specifications

• Package Type: DIP‑16
• Logic Family: 74LS (TTL)
• Operating Voltage (VCC): 4.75 V to 5.25 V
• Operating Temperature (Commercial): 0°C to 70°C
• Propagation Delay Time: 15 ns
• Function: 4‑bit digital magnitude comparator with cascade capability
• I/O Compatibility: TTL/LS‑TTL
• Pin Count: 16

🧩 Typical Applications

• Binary comparison in digital logic systems
• BCD comparison for numerical and display subsystems
• System‑level high‑speed logic where deterministic timing is required
• Computing systems and digital instrumentation
• Industrial control systems and automation
• Educational labs, Arduino projects, and microcontroller prototyping

🔌 Integration Tips (Arduino, Raspberry Pi, Microcontrollers)

• Power the IC at 5 V (VCC = 4.75–5.25 V). This aligns directly with many Arduino boards (e.g., Uno, Mega).
• When interfacing with 3.3 V systems like Raspberry Pi, use a proper logic‑level shifter on the 74LS85 outputs to protect 3.3 V GPIO.
• To compare words wider than 4 bits, use the cascade inputs/outputs to chain multiple 74LS85 devices.
• Keep wiring short and well‑routed to maintain the specified propagation delay and signal integrity.

✅ Why Choose This Module for Your Lab or Project?

• Proven 74LS series reliability for production and education
• Fast, deterministic digital magnitude comparison without firmware overhead
• Excellent for electronics components libraries, modules, and embedded microcontroller designs