SMJ68CE16L-70JDM Legacy Hermetic 128K×8 CMOS Static RAM (SRAM) Overview
The SMJ68CE16L-70JDM 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 non-refresh temporary data storage—ideal for applications where environmental resilience, legacy compatibility, and balanced speed/power efficiency are non-negotiable. Its J-lead DIP (JDM-32) package, 70ns access time, and wide temperature range make it a staple for maintaining older electronics that demand consistent performance in harsh conditions. الشركة المصنعة للدوائر المتكاملة تقدم هذه الذاكرة الصناعية كجزء من محفظتها من أشباه الموصلات الموثوق بها من تكساس إنسترومنتس.
Technical Parameters for SMJ68CE16L-70JDM Industrial SRAM
| المعلمة | القيمة | الوحدة |
|---|---|---|
| الوظيفة | ذاكرة وصول عشوائي ثابتة (SRAM) سعة 128K × 8 | |
| تكوين الذاكرة | 131,072 × 8 | بت (إجمالي 1024 كيلوبايت / 128 كيلوبايت) |
| وقت الوصول (الحد الأقصى) | 70 | نانو ثانية (عند 5 فولت، 25 درجة مئوية) |
| نطاق جهد الإمداد | 4.5 إلى 5.5 | فولت (إمداد واحد، متوافق مع CMOS) |
| تبديد طاقة التهدئة (نموذجي) | 82 | ميجاوات (عند 5 فولت، بدون حمل) |
| نوع الحزمة | JDM-32 (حزمة J-DM-32 (حزمة J-Lead ثنائية الخط، 32 سنًا، سيراميك محكم الإغلاق) | |
| نطاق درجة حرارة التشغيل | -55 إلى +125 | درجة مئوية (درجة صناعية/عسكرية) |
الخصائص الوظيفية الرئيسية
| الخصائص | المواصفات |
|---|---|
| نوع الواجهة | 8 بت متوازية (دبابيس عنوان/بيانات/تحكم متوافقة مع CMOS) |
| توافق عائلة المنطق | TI 74HC/74HCT CMOS, 54LS TTL (دعم نظام الإشارات المختلطة القديمة) |
| هامش الضوضاء (الحد الأدنى) | 0.4 فولت (مستوى منخفض)؛ 0.5 فولت (مستوى عالٍ) (ثبات من الدرجة الصناعية) |
| تيار محرك الإخراج | -8 مللي أمبير (بالوعة)؛ +4 مللي أمبير (مصدر) (نموذجي، متوافق مع CMOS) |
| معايير الموثوقية | متوافق مع MIL-STD-883 (الإحكام، وتدوير درجة الحرارة، والحماية من التفكك الكهرومغناطيسي) |
مزايا تتفوق على حلول الذاكرة القديمة البديلة
The SMJ68CE16L-70JDM outperforms generic SRAMs, plastic-packaged alternatives, and faster but inefficient 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. “We replaced 90ns plastic SRAMs with this model in our 12MHz industrial PLCs, and memory failures dropped from 16% to 0% annually,” confirms a senior engineer at a leading manufacturing automation firm.
🔥 المنتجات الأكثر مبيعًا
Its 70ns access time strikes a perfect balance for mid-speed legacy systems (8–15MHz controllers). Faster 40–50ns SRAMs waste 30% more power for minimal speed gains, while slower 90ns SRAMs cause data lag. For example, a factory sensor hub using a 90ns SRAM took 1.8ms to process 300 8-bit data points; switching to this 70ns model cut time to 1.4ms—fast enough for real-time control without unnecessary energy use.
As a CMOS SRAM, it uses 65% less power than TTL alternatives (82mW vs. 235mW), extending backup battery life by 22% in industrial systems. This is critical for emergency shutdown controllers, where longer battery life prevents operational gaps in remote sites like offshore oil rigs.
🌟 المنتجات المميزة
The JDM-32’s J-lead design creates 2x stronger solder joints than standard through-hole pins, reducing vibration failures in factory robots or aircraft. Unlike modern surface-mount SRAMs, it fits legacy JDM-32 sockets—avoiding costly PCB redesigns. Its -55°C to +125°C range also outperforms commercial SRAMs (0°C–70°C), working reliably in freezing arctic sensors or hot desert-based equipment.
Typical Applications of SMJ68CE16L-70JDM
The SMJ68CE16L-70JDM excels in legacy and mission-critical systems where ruggedness, balanced efficiency, and compatibility matter. Key use cases include:
📩 اتصل بنا
- Aerospace and Defense (avionics data buffers, missile guidance system memory, satellite ground station loggers)
- Industrial Automation (8–15MHz 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 processors)
- Test and Measurement (ruggedized signal generators, environmental stress test equipment, legacy oscilloscope memory)
- Security and Surveillance (military perimeter sensor data buffers, legacy outdoor camera recording modules)
خبرات شركة تكساس إنسترومنتس في ذاكرة CMOS المحكمية
As a Texas Instruments product, the SMJ68CE16L-70JDM leverages TI’s 70+ years of leadership in industrial and military-grade semiconductors. TI’s hermetic CMOS SRAMs undergo rigorous testing: temperature cycling (-55°C to +125°C for 1,000 cycles), humidity resistance (85% RH at 85°C for 1,000 hours), and ESD protection (2kV human-body model, per MIL-STD-883).
This durability makes TI a trusted partner for Boeing (aerospace), Siemens (industrial automation), and Lockheed Martin (defense)—all rely on TI’s legacy memory to maintain critical older systems. For businesses managing legacy infrastructure, TI’s components ensure continuity without sacrificing reliability or efficiency.
الأسئلة المتداولة (FAQ)
What is the SMJ68CE16L-70JDM, and how does it support legacy systems?
The SMJ68CE16L-70JDM is a 128K×8 hermetic CMOS SRAM for legacy industrial/aerospace systems. It stores 131,072 independent 8-bit values without power refresh. Via CMOS-compatible parallel pins, it reads/writes in 70ns, syncing with 8–15MHz controllers (e.g., 54LS TTL PLCs) to deliver real-time performance without wasted power.
Why is 70ns access time ideal for 8–15MHz industrial PLCs?
8–15MHz PLCs operate on 67–125ns cycles. A 70ns access time matches this range: fast enough to avoid data lag, but not so fast that it wastes power (unlike 40ns SRAMs, which use 30% more energy). This balance cuts operational costs and extends backup battery life for critical systems.
كيف تعمل حزمة JDM-32 على تحسين الموثوقية في البيئات القاسية؟
The JDM-32’s hermetic ceramic enclosure seals the SRAM in inert gas, blocking salt, dust, or chemicals that degrade plastic DIPs. Its J-lead pins form larger solder joints, resisting vibration. This design ensures 10+ years of use vs. 2–3 years for plastic SRAMs in coastal/factory environments.
What benefits does CMOS technology offer over TTL for this SRAM?
CMOS cuts power use by 65% (82mW vs. 235mW for TTL), extending battery life in backups. 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—reducing data corruption errors by 40%.
Is the SMJ68CE16L-70JDM compatible with mixed-signal legacy systems?
Yes. It works with TI 54LS TTL controllers and 74HC/74HCT CMOS sensors—no logic translators needed, thanks to TTL-compatible CMOS I/O levels. It fits existing JDM-32 sockets, letting technicians replace older SRAMs without PCB modifications—saving time and avoiding costly redesigns.
