Texas Instruments SMJ64C16S-35JDM 16K×8 SRAM, JDM-24 - 35ns CMOS Hermético

SMJ64C16S-35JDM Legacy Hermetic 16K×8 CMOS Static RAM (SRAM) Overview

The SMJ64C16S-35JDM from Texas Instruments is a high-reliability 16K×8 static random-access memory (SRAM) engineered for high-speed legacy industrial, aerospace, and defense systems. Part of TI’s trusted portfolio of hermetic memory components, it delivers ultra-fast, non-refresh temporary data storage—ideal for applications where speed, environmental resilience, and legacy compatibility are non-negotiable. Its J-lead DIP (JDM-24) package, 35ns access time, and wide temperature range make it a staple for maintaining older electronics that demand consistent, high-performance data handling in harsh conditions. Fabricante de CI ofrece este componente de memoria de calidad industrial como parte de su cartera de semiconductores de confianza de Texas Instruments.

Technical Parameters for SMJ64C16S-35JDM Industrial SRAM

Parámetro	Valor	Unidad
Función	16K×8 Static Random-Access Memory (SRAM)
Configuración de la memoria	16,384 × 8	Bits (128 Kbits / 16 Kbytes total)
Tiempo de acceso (máx.)	35	ns (a 5V, 25°C)
Rango de tensión de alimentación	4,5 a 5,5	V (alimentación única, compatible con CMOS)
Disipación de potencia en reposo (típica)	80	mW (a 5 V, sin carga)
Tipo de envase	JDM-24 (J-Lead Dual In-Line Package, 24-pin, hermetic ceramic)
Temperatura de funcionamiento	-55 a +125	°C (grado industrial/militar)

Características funcionales clave

Característica	Especificación
Tipo de interfaz	8 bits en paralelo (pines de dirección/datos/control compatibles con CMOS)
Compatibilidad de familias lógicas	TI 74HC/74HCT CMOS, 54LS TTL (compatibilidad con sistemas heredados de señal mixta)
Margen de ruido (mín.)	0,4 V (nivel bajo); 0,5 V (nivel alto) (estabilidad industrial)
Corriente de salida	-8mA (sink); +4mA (source) (típico, CMOS-compliant)
Normas de fiabilidad	Conforme a MIL-STD-883 (hermeticidad, ciclos de temperatura, protección ESD)

Ventajas sobre otras soluciones de memoria heredada

The SMJ64C16S-35JDM outperforms generic SRAMs, plastic-packaged alternatives, and slower 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 50ns plastic SRAMs with this model in our 28MHz industrial PLCs, and production line downtime from memory lag dropped by 40%,” confirms a senior engineer at a leading automotive manufacturing firm.

Its 35ns access time is 30% faster than 50ns SRAMs, eliminating micro-lag in high-speed legacy systems (25–30MHz controllers). For example, a factory sensor hub using a 50ns SRAM took 1.0ms to process 200 8-bit sensor data points; switching to this 35ns model cut processing time to 0.7ms. This ensured the PLC received data in time to adjust motor speeds, reducing defective parts by 35% in high-speed assembly lines—directly boosting throughput and reducing waste.

As a CMOS SRAM, it uses 65% less power than TTL alternatives (80mW vs. 225mW), extending backup battery life in industrial systems by 30% during power outages. This is a critical benefit for safety-critical equipment like emergency shutdown controllers, where prolonged battery life prevents operational gaps or safety risks—especially in remote industrial sites with limited backup power.

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, complexity, and potential failure points. Its -55°C to +125°C temperature range also outperforms commercial-grade SRAMs (limited to 0°C–70°C), ensuring consistent performance in freezing arctic sensors, hot engine bays, or coastal radar systems.

Typical Applications of SMJ64C16S-35JDM

The SMJ64C16S-35JDM excels in legacy and mission-critical systems where ultra-fast speed, ruggedness, and compatibility are non-negotiable. Key use cases include:

• Aerospace and Defense (avionics telemetry buffers, missile guidance system memory, radar target tracking loggers, high-speed flight test data recorders)
• Industrial Automation (25–30MHz legacy PLCs, factory high-speed sensor hubs, precision machine tool controllers, automotive assembly line sync systems)
• Test and Measurement (high-frequency oscilloscopes, dynamic strain gauges, ruggedized signal generators, environmental stress test equipment)
• Energy and Power (oil/gas well high-speed monitoring controllers, wind turbine pitch control sensor memory, high-voltage substation data processors)
• Security and Surveillance (military perimeter radar data buffers, legacy high-speed camera recording modules, threat detection system memory)

Experiencia de Texas Instruments en memorias CMOS herméticas

As a Texas Instruments product, the SMJ64C16S-35JDM leverages TI’s 70+ years of leadership in industrial and military-grade semiconductors. TI’s hermetic CMOS SRAMs are not just built for performance—they are engineered for longevity. Each unit undergoes rigorous testing to meet strict global standards: temperature cycling (-55°C to +125°C for 1,000 cycles), humidity resistance (85% RH at 85°C for 1,000 hours), and electrostatic discharge (ESD) protection (2kV human-body model, per MIL-STD-883 Method 3015).

This commitment to durability has made TI a trusted partner for industry leaders like Boeing (aerospace), Siemens (industrial automation), and Lockheed Martin (defense)—all of which rely on TI’s legacy memory components to maintain critical older systems that cannot be easily replaced. For businesses managing high-speed legacy infrastructure, TI’s components ensure continuity without sacrificing speed, efficiency, or reliability.

Preguntas más frecuentes (FAQ)

What is the SMJ64C16S-35JDM, and how does it support high-speed legacy systems?

The SMJ64C16S-35JDM is a 16K×8 hermetic CMOS SRAM designed for high-speed legacy industrial, aerospace, and defense systems. It stores temporary data without requiring power refresh (a core advantage of SRAM technology) and retains 16,384 independent 8-bit data values. Via its CMOS-compatible parallel interface, it reads and writes data in 35ns—fast enough to sync with 25–30MHz controllers (e.g., TI 54LS TTL PLCs) and eliminate the micro-lag that disrupts high-speed operations.

Why is 35ns access time critical for 25–30MHz industrial PLCs?

25–30MHz PLCs operate on cycles of 33–40 nanoseconds (ns) per instruction. A 35ns access time aligns perfectly with this range, ensuring the SRAM delivers data to the PLC exactly when needed—no delays, no lag. Slower 50ns SRAMs create a 10–17ns lag per cycle, which accumulates over hundreds of instructions to cause 10–17ms delays. These delays misalign high-speed conveyors, miscalculate sensor readings, or trigger false safety alerts—all of which lead to costly downtime, defective products, or even safety risks.

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

The JDM-24 package is a hermetic ceramic J-lead dual in-line package (DIP) optimized for harsh conditions. Unlike plastic DIPs (which absorb moisture, dust, and chemicals over time), the JDM-24’s ceramic enclosure is sealed with an inert gas—blocking contaminants like salt (coastal environments), factory dust, or oil/gas chemicals from reaching the chip. Its J-lead pins also form larger, more vibration-resistant solder joints with PCBs than straight pins, reducing failure risk in high-vibration systems like factory robots or aircraft.

What benefits does CMOS technology offer over TTL for this SRAM?

CMOS technology delivers two key advantages over TTL (Transistor-Transistor Logic) for this SRAM: lower power consumption and better noise immunity. At 80mW (typical quiescent power), it uses 65% less energy than TTL SRAMs (which consume ~225mW), extending battery life in backup-powered systems—critical for remote industrial sites. It also has a wider noise margin (0.4V for low levels, 0.5V for high levels) vs. TTL’s 0.3V margin, making it more resistant to electrical interference from factory motors or radar systems—cutting data corruption errors by 45%.

Is the SMJ64C16S-35JDM compatible with mixed-signal legacy systems (TTL + CMOS)?

Yes, it is fully compatible with mixed-signal legacy systems that use both TI 54LS TTL controllers and 74HC/74HCT CMOS sensors. Its CMOS input/output (I/O) levels are TTL-compatible (VIL ≤ 0.8V, VIH ≥ 2.0V), so it can read data from CMOS sensors and send commands to TTL controllers without needing logic level translators. Additionally, it fits existing JDM-24 sockets, so technicians can replace older SRAMs without modifying PCBs—saving time and avoiding the cost of redesigning legacy infrastructure.