Texas Instruments SMJ68CE16S-45JDM 128K×8 SRAM, JDM-32 - 45ns Hermetisch CMOS

SMJ68CE16S-45JDM Legacy Hermetic 128K×8 CMOS Static RAM (SRAM) Overview

The SMJ68CE16S-45JDM from Texas Instruments is a high-reliability 128K×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 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-32) package, 45ns access time, and wide temperature range make it a staple for maintaining older electronics that demand consistent, high-performance data handling in harsh conditions. IC-fabrikant biedt deze geheugencomponent van industriële kwaliteit aan als onderdeel van zijn portfolio van vertrouwde Texas Instruments halfgeleiders.

Technical Parameters for SMJ68CE16S-45JDM Industrial SRAM

Belangrijkste functionele kenmerken

Voordelen ten opzichte van alternatieve legacygeheugenoplossingen

The SMJ68CE16S-45JDM outperforms generic SRAMs, plastic-packaged alternatives, and slower memory options, starting with its hermetic JDM-32 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 60ns plastic SRAMs with this model in our 22MHz aerospace radar loggers, and target tracking errors dropped by 30%,” confirms a senior engineer at a leading defense electronics firm.

Its 45ns access time is 25% faster than 60ns SRAMs, eliminating micro-lag in high-speed legacy systems (20–25MHz controllers). For example, a factory sensor hub using a 60ns SRAM took 1.2ms to process 250 8-bit sensor data points; switching to this 45ns model cut processing time to 0.9ms. This ensured the PLC received data in time to adjust motor speeds, reducing defective parts by 32% in high-speed assembly lines—directly boosting throughput.

As a CMOS SRAM, it uses 60% less power than TTL alternatives (90mW vs. 225mW), extending backup battery life in industrial systems by 28% 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.

The JDM-32’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 failure points. Its -55°C to +125°C temperature range also outperforms commercial-grade SRAMs (0°C–70°C), ensuring performance in freezing arctic sensors, hot engine bays, or coastal radar systems.

Typical Applications of SMJ68CE16S-45JDM

The SMJ68CE16S-45JDM 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 data buffers, missile guidance system memory, radar target tracking loggers, flight test data recorders)
• Industrial Automation (20–25MHz legacy PLCs, factory sensor hubs, high-speed production line controllers, precision machine tools)
• Test and Measurement (ruggedized signal generators, high-frequency oscilloscopes, dynamic strain gauges, environmental stress test equipment)
• Energy and Power (oil/gas well high-speed monitoring controllers, wind turbine pitch control sensor memory)
• Security and Surveillance (military perimeter radar data buffers, legacy high-speed camera recording modules)

Texas Instruments' expertise in hermetisch CMOS-geheugen

As a Texas Instruments product, the SMJ68CE16S-45JDM leverages TI’s 70+ years of leadership in industrial and military-grade semiconductors. TI’s hermetic CMOS SRAMs are engineered for both performance and 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 or reliability.

Veelgestelde vragen (FAQ)

What is the SMJ68CE16S-45JDM, and how does it support high-speed legacy systems?

The SMJ68CE16S-45JDM is a 128K×8 hermetic CMOS SRAM designed for high-speed legacy industrial, aerospace, and defense systems. It stores temporary data without power refresh (a core SRAM benefit) and retains 131,072 independent 8-bit values. Via its CMOS-compatible parallel interface, it reads/writes data in 45ns—fast enough to sync with 20–25MHz controllers (e.g., TI 54LS TTL PLCs) and avoid the micro-lag that disrupts high-speed operations.

Why is 45ns access time critical for 20–25MHz industrial PLCs?

20–25MHz PLCs operate on 40–50ns cycles. A 45ns access time aligns with this range, ensuring the SRAM delivers data exactly when the PLC needs it. Slower 60ns SRAMs create a 10–20ns lag per cycle, which accumulates over 1,000 cycles to cause 10–20ms delays. These delays misalign high-speed conveyors, miscalculate sensor readings, or trigger false safety alerts—all leading to costly downtime or defective products.

How does the JDM-32 package improve reliability in coastal or industrial environments?

The JDM-32’s hermetic ceramic enclosure seals the SRAM in inert gas, blocking salt (coastal), dust (factories), or chemicals (oil/gas sites) that degrade plastic DIPs. Its J-lead pins form larger, vibration-resistant solder joints with PCBs—critical for factory robots or aircraft, where vibration breaks standard through-hole joints. This design ensures 10+ years of use vs. 2–3 years for plastic SRAMs.

Welke voordelen biedt CMOS-technologie boven TTL voor dit SRAM?

CMOS technology cuts power use by 60% (90mW vs. 225mW for TTL), extending backup battery life in critical systems. It also has a wider noise margin (0.4V–0.5V vs. TTL’s 0.3V), making it more resistant to electrical interference from factory motors or radar—reducing data corruption errors by 40% and minimizing unplanned downtime.

Is the SMJ68CE16S-45JDM compatible with mixed-signal legacy systems (TTL + CMOS)?

Yes. It works seamlessly with mixed-signal systems using TI 54LS TTL controllers and 74HC/74HCT CMOS sensors. Its CMOS I/O levels are TTL-compatible (VIL ≤ 0.8V, VIH ≥ 2.0V), so no logic translators are needed. It also fits existing JDM-32 sockets, letting technicians replace older SRAMs without PCB modifications—saving time and avoiding costly infrastructure overhauls.