# 231 series integrated circuits

> Early Soviet RTL hybrid circuit based on 111 series dies

**Wikidata**: [Q130446680](https://www.wikidata.org/wiki/Q130446680)  
**Source**: https://4ort.xyz/entity/231-series-integrated-circuits

## Summary
The 231 series integrated circuits were early Soviet hybrid circuits developed by Angstrem in 1970, based on the 111 series dies and using resistor–transistor logic (RTL). They were part of a broader Soviet integrated circuit designation system and combined different semiconductor devices and passive components on a substrate.

## Key Facts
- **Instance of**: Integrated circuit series and resistor–transistor logic (RTL) circuit
- **Subclass of**: Hybrid integrated circuit
- **Uses**: 111 series integrated circuits as a base
- **Developer and manufacturer**: Angstrem
- **Country of origin**: Soviet Union
- **Complies with**: Soviet integrated circuit designation standards
- **Point in time**: Introduced in 1970
- **Image available**: [231ie1_2.jpg](https://commons.wikimedia.org/wiki/Special:FilePath/231ie1_2.jpg)
- **Commons category**: 231 series integrated circuits

## FAQs
### Q: What type of technology did the 231 series use?
A: The 231 series used resistor–transistor logic (RTL), a common early integrated circuit design in the Soviet Union.

### Q: Who developed the 231 series integrated circuits?
A: The 231 series was developed by Angstrem, a Soviet electronics manufacturer.

### Q: How does the 231 series relate to the 111 series?
A: The 231 series was based on the 111 series dies, indicating a direct lineage in Soviet integrated circuit design.

### Q: What was the significance of the Soviet integrated circuit designation?
A: The Soviet integrated circuit designation system, which the 231 series followed, standardized the naming and classification of early Soviet electronics components.

### Q: Are there any images available of the 231 series?
A: Yes, an image of the 231 series is available on Wikimedia Commons: [231ie1_2.jpg](https://commons.wikimedia.org/wiki/Special:FilePath/231ie1_2.jpg).

## Why It Matters
The 231 series integrated circuits represent a key development in Soviet electronics, bridging early hybrid circuit technology with the broader integrated circuit series. As part of the Soviet integrated circuit designation system, they contributed to the standardization and advancement of electronic components in the Cold War era. Their use of RTL and hybrid design principles reflects the constraints and innovations of Soviet engineering during the 1970s. While less documented than Western counterparts, the 231 series highlights the Soviet Union’s independent contributions to early integrated circuit technology.

## Notable For
- **Hybrid design**: Combined semiconductor devices and passive components on a substrate, a hallmark of early Soviet electronics.
- **RTL implementation**: Used resistor–transistor logic, a common but less publicized design in the Soviet context.
- **Soviet standardization**: Followed the Soviet integrated circuit designation system, ensuring compatibility with other Soviet-era components.
- **Angstrem development**: Developed by Angstrem, a significant Soviet electronics manufacturer.
- **1970 introduction**: Marked a key milestone in Soviet integrated circuit production.

## Body
### Classification and Design
The 231 series is classified as both an **integrated circuit series** and a **hybrid integrated circuit**, meaning it combined multiple semiconductor devices and passive components on a single substrate. This hybrid approach was common in early Soviet electronics, balancing miniaturization with functional integration.

### Technology and Development
Developed by **Angstrem**, the 231 series used **resistor–transistor logic (RTL)**, a design philosophy that relied on resistors and transistors to perform logic operations. This was a common approach in the Soviet Union during the 1970s, though less documented than Western RTL implementations.

### Relationship to Other Series
The 231 series was directly based on the **111 series dies**, indicating a lineage in Soviet integrated circuit design. Both series were part of the broader **Soviet integrated circuit designation system**, which standardized naming and classification for early electronics components.

### Historical Context
Introduced in **1970**, the 231 series reflects the Soviet Union’s independent development of integrated circuit technology during the Cold War. While less publicized than Western advancements, it contributed to the Soviet electronics industry’s capabilities in the 1970s.

### Media and Documentation
An image of the 231 series is available on **Wikimedia Commons**, providing visual documentation of the circuits. The series is also categorized under **231 series integrated circuits** in the Commons, aiding further research.