Subelement E: Digital Logic— Topic 33: Types of Logic
Question 3-33E3
Element 3 (GROL)What is the common power supply voltage for TTL series integrated circuits?
Explanation
TTL (Transistor-Transistor Logic) integrated circuits are a foundational family of digital logic widely used in electronics, including many amateur radio projects and equipment. These devices are specifically designed to operate with a nominal power supply voltage of **5 volts DC**. This voltage provides the correct bias for the internal transistors and ensures reliable switching between logic "high" and logic "low" states.
* **A) 12 volts** and **B) 13.6 volts** are common power supply voltages for general amateur radio equipment, often derived from car batteries or AC-to-DC converters. However, these voltages are significantly too high for standard TTL ICs and would likely cause irreparable damage.
* **C) 1 volt** is far too low to properly power TTL circuits, which require a higher voltage to define their logic levels and operate their internal components.
Related Questions
3-33E1 What is the voltage range considered to be valid logic low input in a TTL device operating at 5 volts?3-33E2 What is the voltage range considered to be a valid logic high input in a TTL device operating at 5.0 volts?3-33E4 TTL inputs left open develop what logic state?3-33E5 Which of the following instruments would be best for checking a TTL logic circuit?3-33E6 What do the initials TTL stand for?