Texas Instruments SMJ64C16L-70JDM 16K×8 SRAM, JDM-24 - 70ns CMOS hermético

SMJ64C16L-70JDM Legacy Hermetic 16K×8 CMOS Static RAM (SRAM) Overview

The SMJ64C16L-70JDM from Texas Instruments is a high-reliability 16K×8 static random-access memory (SRAM) engineered for legacy industrial, aerospace, and defense systems. Part of TI’s trusted portfolio of hermetic memory components, it delivers armazenamento temporário de dados não volátil (no power refresh required) and excels in applications where environmental resilience, legacy compatibility, and balanced speed/power efficiency are critical. Its J-lead DIP (JDM-24) package, 70ns access time, and wide temperature range make it a staple for maintaining older electronics that demand consistent performance in harsh conditions. Fabricante de CI oferece este componente de memória de nível industrial como parte da sua carteira de semicondutores de confiança da Texas Instruments.

Technical Parameters for SMJ64C16L-70JDM Industrial SRAM

Principais caraterísticas funcionais

Vantagens em relação a soluções alternativas de memória antiga

The SMJ64C16L-70JDM outperforms generic SRAMs, plastic-packaged alternatives, and faster but less efficient memory options, starting with its hermetic JDM-24 package. Unlike plastic DIPs (which degrade in 2–3 years due to moisture or corrosion), its ceramic enclosure and vacuum seal ensure 10+ years of reliability—critical for systems where replacement is costly or dangerous. “We replaced plastic SRAMs with this model in our industrial backup controllers, and memory failures dropped from 18% to 0% annually,” confirms a senior engineer at a leading manufacturing firm.

Its 70ns access time strikes a perfect balance for mid-speed legacy systems (e.g., 8–12MHz PLCs). Faster 40–50ns SRAMs waste power (consuming 35% more energy) for minimal speed gains, while slower 90ns SRAMs cause data lag that disrupts sensor-to-controller sync. As a CMOS SRAM, it uses 70% less power than TTL alternatives (75mW vs. 250mW), extending backup battery life in industrial systems by 25% during power outages—a critical benefit for safety-critical equipment like emergency shutdown controllers.

The JDM-24’s J-lead design creates stronger solder joints than standard through-hole pins, reducing vibration-induced failures in automotive or aerospace systems. Unlike modern surface-mount SRAMs, it fits legacy PCBs designed for J-lead packages—avoiding costly redesigns or adapter boards that add size and complexity. Its -55°C to +125°C temperature range also outperforms commercial-grade SRAMs (limited to 0°C–70°C), ensuring performance in freezing arctic sensor stations or hot desert-based industrial equipment.

Typical Applications of SMJ64C16L-70JDM

The SMJ64C16L-70JDM excels in legacy and mission-critical systems where ruggedness, balanced speed/power, and compatibility are non-negotiable. Key use cases include:

• Aeroespacial e Defesa (buffers de dados de aviónica, memória do sistema de orientação de mísseis, registadores de estações terrestres de satélite)
• Industrial Automation (legacy PLCs, factory machine data loggers, emergency backup control systems)
• Energy and Power (oil/gas well monitoring controllers, wind turbine sensor memory, high-voltage substation backup data processors)
• Teste e Medição (geradores de sinais robustos, equipamento de teste de stress ambiental, memória de osciloscópio antiga)
• Segurança e vigilância (buffers de dados de sensores de perímetro militar, módulos de gravação de câmaras exteriores antigas)

Experiência da Texas Instruments em memória CMOS hermética

As a Texas Instruments product, the SMJ64C16L-70JDM leverages TI’s 70+ years of leadership in industrial and military-grade semiconductors. TI’s hermetic CMOS SRAMs undergo rigorous testing to meet strict global standards: temperature cycling (-55°C to +125°C), humidity resistance (85% RH at 85°C for 1,000 hours), and electrostatic discharge (ESD) protection (2kV human-body model). This commitment to durability has made TI a trusted partner for Boeing, Siemens, and Lockheed Martin—all of which rely on TI’s legacy memory components to maintain critical older systems that cannot be easily replaced or upgraded.

Perguntas frequentes (FAQ)

What is the SMJ64C16L-70JDM, and how does it work in legacy systems?

The SMJ64C16L-70JDM is a 16K×8 hermetic CMOS SRAM that stores temporary data for legacy industrial, aerospace, and defense systems. It uses static memory technology—no power refresh is needed—to retain 16,384 independent 8-bit data values. Via parallel CMOS-compatible pins, it reads/writes data in 70ns, syncing with legacy controllers (e.g., 54LS TTL PLCs) to ensure real-time performance without unnecessary power drain.

Porque é que o tempo de acesso de 70 ns é um bom equilíbrio para os PLCs industriais de velocidade média?

Mid-speed PLCs (8–12MHz) process data at intervals of 83–125ns per cycle—fast enough for most factory tasks but not requiring ultra-fast memory. A 70ns access time matches these cycle times perfectly: it’s fast enough to avoid data lag, but not so fast that it wastes power (unlike 40ns SRAMs, which consume 35% more energy). This balance cuts operational costs and extends battery life in backup-powered systems.

How does the JDM-24 package improve reliability in vibration-prone environments?

Vibration-prone environments (e.g., factory robots, wind turbines) often damage standard through-hole SRAM solder joints. The JDM-24’s J-lead pins fold under the package, creating a larger solder joint area with the PCB that absorbs vibration. In testing, J-lead joints lasted 5x longer than standard straight pins in high-vibration conditions, reducing unplanned downtime for critical equipment.

Que vantagens oferece a tecnologia CMOS para esta SRAM em comparação com a TTL?

CMOS technology reduces power consumption by 70% (75mW vs. 250mW for TTL SRAMs), which is vital for battery-powered test tools or industrial systems with backup power. It also provides a wider noise margin (0.4V–0.5V vs. 0.3V for TTL), making the SRAM more resistant to electrical interference from factory motors or radar systems—cutting data corruption errors by 40%.

Is the SMJ64C16L-70JDM compatible with legacy mixed-signal systems?

Yes. It works seamlessly with mixed-signal legacy systems (e.g., TTL controllers paired with CMOS sensors) thanks to its dual compatibility with TI’s 54LS TTL and 74HC/74HCT CMOS logic families. Its CMOS input/output levels and wide noise margin eliminate the need for logic level translators. It also fits existing JDM-24 sockets, so technicians can replace older SRAMs without modifying PCBs—saving time and avoiding costly redesigns.