Texas Instruments SMJ64C16S-55JDM 16K×8 SRAM, JDM-24 - 55ns CMOS hermético

SMJ64C16S-55JDM Legacy Hermetic 16K×8 CMOS Static RAM (SRAM) Overview

The SMJ64C16S-55JDM 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 provides fast temporary data storage with no power refresh needed—ideal for applications where environmental resilience and legacy compatibility are non-negotiable. Its J-lead DIP (JDM-24) package, 55ns access time, and wide temperature range ensure seamless integration with older electronics while enduring harsh conditions like high heat or corrosion. 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 SMJ64C16S-55JDM Industrial SRAM

Parâmetro	Valor	Unidade
Função	Memória estática de acesso aleatório (SRAM) de 16K×8
Configuração da memória	16,384 × 8	Bits (128 Kbits / 16 Kbytes total)
Tempo de acesso (máximo)	55	ns (a 5V, 25°C)
Gama de tensão de alimentação	4,5 a 5,5	V (alimentação única, compatível com CMOS)
Dissipação de potência quiescente (típica)	85	mW (a 5V, sem carga)
Tipo de embalagem	JDM-24 (Pacote J-Lead Dual In-Line, 24 pinos, cerâmica hermética)
Gama de temperaturas de funcionamento	-55 a +125	°C (de tipo industrial/militar)

Principais caraterísticas funcionais

Caraterística	Especificação
Tipo de interface	Paralelo de 8 bits (pinos de endereço/dados/controlo compatíveis com CMOS)
Compatibilidade de famílias lógicas	TI 74HC/74HCT CMOS, 54LS TTL (suporte de sistema legado de sinal misto)
Margem de ruído (mín.)	0,4V (nível baixo); 0,5V (nível alto) (estabilidade de nível industrial)
Corrente de acionamento de saída	-8mA (dissipador); +4mA (fonte) (típico, compatível com CMOS)
Normas de fiabilidade	Em conformidade com a norma MIL-STD-883 (hermeticidade, ciclos de temperatura, proteção ESD)

Vantagens em relação a soluções alternativas de memória antiga

The SMJ64C16S-55JDM outperforms generic SRAMs and plastic-packaged alternatives, 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 generic plastic SRAMs with this component in our factory PLCs, and unplanned downtime from memory failures dropped by 80%,” confirms a senior engineer at a leading manufacturing firm.

Its 55ns access time balances speed and efficiency for mid-speed legacy systems (e.g., 10–20MHz controllers). Slower 70ns SRAMs cause data lag, leading to unsynchronized machine control in production lines, while faster 40ns SRAMs waste power—unnecessary for non-high-speed applications. As a CMOS SRAM, it consumes 60% less power than TTL alternatives (85mW vs. 210mW), extending battery life in portable test tools by 25%.

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 warehouse sensors or hot desert-based industrial equipment.

Typical Applications of SMJ64C16S-55JDM

The SMJ64C16S-55JDM excels in legacy and mission-critical systems where ruggedness, speed, 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)
• Automação industrial (PLCs antigos, registadores de dados de máquinas de fábrica, sistemas de controlo de processos a altas temperaturas)
• Teste e Medição (geradores de sinais robustos, equipamento de teste de stress ambiental, memória de osciloscópio antiga)
• Energy and Power (oil/gas well monitoring controllers, high-voltage substation data processors, wind turbine sensor memory)
• 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 SMJ64C16S-55JDM 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 SMJ64C16S-55JDM, and how does it work in legacy systems?

The SMJ64C16S-55JDM 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 55ns, syncing with legacy controllers (e.g., 54LS TTL PLCs) to ensure real-time performance without lag.

Why is 55ns access time important for industrial data loggers?

Industrial data loggers capture sensor data at intervals as short as 2ms, requiring memory that can store/retrieve data quickly. A 55ns access time means the SRAM can process one data point in 55 billionths of a second—fast enough to keep up with 18MHz controller clock speeds. Slower 70ns SRAMs would cause buffer overflow, leading to lost data points that result in incomplete quality control records or machine health monitoring gaps.

How does the JDM-24 package improve reliability in coastal or industrial environments?

Coastal and industrial environments expose electronics to salt, dust, or chemicals that corrode plastic and metal. The JDM-24’s hermetic ceramic enclosure seals the SRAM in an inert gas, blocking contaminants. Its J-lead pins also create a larger solder joint area with PCBs than straight pins, resisting corrosion and vibration. This design ensures 10+ years of use vs. 2–3 years for plastic DIP SRAMs in these harsh conditions.

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

CMOS technology reduces power consumption by 60% (85mW vs. 210mW for TTL SRAMs), which is vital for battery-powered test tools or energy-constrained industrial systems. 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 35%.

Is the SMJ64C16S-55JDM 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.