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Renesas 71256L35DB
- Part No.:
- 71256L35DB
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-CDIP (0.600", 15.24mm)
- Datasheet:
-
71256L35DB.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28CDIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,094
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Product details
Overview
71256L35DB from Renesas Electronics is a 256K (32K × 8-bit) low-power CMOS static RAM with military-grade reliability, 35ns maximum access time, 2V data retention capability, and compliance with MIL-STD-883 Class B. It serves as non-volatile SRAM buffer in avionics control units requiring deterministic timing and battery-backed memory persistence during power loss.
For engineers reviewing the 71256L35DB datasheet, 71256L35DB pinout, 71256L35DB application, or 71256L35DB equivalent, key selection criteria include military temperature range (–55°C to +125°C), ceramic DIP package compatibility, TTL-level I/O interface, and standby current of 3mA at VCC = 5.5V.
Technical Context
This device implements a fully decoded 15-bit address space (A0–A14) driving a 262,144-bit memory array with bidirectional 8-bit I/O (I/O0–I/O7). Chip Select (CS), Write Enable (WE), and Output Enable (OE) provide three-level control for read/write/standby state transitions.
Its dual standby modes-TTL-level (ISB = 3mA) and CMOS-level (ISB1 = 1.5mA)-are triggered by CS logic level, enabling system-level power optimization without external sequencing. Data retention at 2V is guaranteed across full military temperature range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 256Kbit (32K × 8-bit) - supports byte-wide data bus interfacing without external multiplexing |
| Access Time | 35ns max - ensures sub-28.6MHz synchronous read cycles in real-time control loops |
| Supply Voltage | 5.0V ±10% - compatible with legacy 5V TTL logic families and industrial power rails |
| Standby Current | 3mA (TTL-level CS) - reduces system idle power by >90% vs active operation (115mA) |
| Data Retention | 2V minimum - enables direct connection to backup lithium battery without regulator |
| Operating Temp | –55°C to +125°C - qualified for airborne and ground vehicle mission-critical environments |
| Package | 28-pin 600-mil ceramic DIP (CD28) - provides hermetic sealing and thermal stability under shock/vibration |
Pinout & Package
71256L35DB uses a 28-pin ceramic dual in-line package (CD28, 600-mil width) with through-hole mounting and hermetic ceramic construction for military environmental resilience.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit parallel address bus accepting full 32K address space; TTL-compatible thresholds |
| I/O0–I/O7 | Data Input/Output | Bidirectional 8-bit data path with high-impedance tri-state control via OE/WE/CS |
| CS | Chip Select | Active-low enable controlling both access and automatic entry into low-power standby mode |
| WE | Write Enable | Active-low signal gating write operations; determines write cycle timing (tWC = 35ns) |
| OE | Output Enable | Active-low control for output drivers; allows read data to appear on I/O lines only when asserted |
| VCC | Power Supply | +5V supply pin; supports 4.5–5.5V range with 1W max power dissipation rating |
| GND | Ground Reference | Signal and power return path; requires low-impedance PCB plane for noise immunity |
Key Features
| Feature | Design Value |
|---|---|
| MIL-STD-883 Class B compliance | Qualified for high-reliability defense/aerospace systems with full screening, burn-in, and environmental stress testing |
| 2V data retention | Operates in battery-backup mode down to 2.0V, eliminating need for external voltage supervisor or regulator |
| TTL-compatible I/O | Direct interface with legacy 5V microcontrollers and FPGAs without level-shifting circuitry |
| Dual standby modes | Reduces power to 3mA (TTL CS) or 1.5mA (CMOS CS), enabling adaptive power management in multi-voltage systems |
| Hermetic ceramic DIP | 600-mil CD28 package resists moisture ingress, thermal cycling, and mechanical shock per MIL-STD-202 |
Applications
| Avionics Flight Control Unit | Tactical Radio Transceiver Buffer |
|---|---|
|
Use Scenario: Real-time storage of flight parameter logs and control command history during engine start-up and in-flight power transients. IC Role / Device Role / Timing Role: Non-volatile SRAM buffer retaining critical telemetry even during 500ms main power interruption. Use Value: Eliminates need for external EEPROM write cycles, reducing latency and wear-out in safety-critical logging. |
Use Scenario: Storing encrypted voice packet headers and channel configuration tables in manpack radios operating across desert and arctic environments. IC Role / Device Role / Timing Role: High-speed, temperature-stable memory for rapid header lookup and cipher key caching. Use Value: Guarantees 35ns access at –55°C and +125°C, enabling deterministic MAC-layer processing under extreme thermal stress. |
| Missile Guidance System Memory | Armored Vehicle C4ISR Terminal |
|
Use Scenario: Holding target acquisition coordinates and inertial navigation updates during launch vibration and electromagnetic pulse events. IC Role / Device Role / Timing Role: Radiation-tolerant, hermetically sealed SRAM preserving mission-critical data during high-G acceleration. Use Value: Ceramic DIP package and MIL-STD-883 qualification ensure zero bit errors under 20,000g shock profiles. |
Use Scenario: Caching battlefield map tiles and encrypted comms keys in mobile command posts subjected to repeated thermal cycling and EMI. IC Role / Device Role / Timing Role: Low-power standby mode (3mA) extends battery life during extended reconnaissance missions. Use Value: 2V data retention allows direct integration with 3.6V LiSOCl₂ primary batteries via simple resistive divider. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar static RAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| IS61LV25616AL-10TLI | 3.3V-only supply, 10ns access, 44-pin TSOP-II package | Lacks military temp rating and 2V retention; suited for commercial embedded systems | Select only if migrating to 3.3V architecture and waiving MIL-STD-883 requirements |
| CY62128EV30LL-45ZSXI | 5V supply, 45ns access, SOIC-28 package, no 2V retention | Industrial temp only (–40°C to +85°C); lower cost but unqualified for airborne use | Acceptable for ground-based test equipment where hermeticity and extended temp are not required |
Compared with 71256L35DB, IS61LV25616AL-10TLI offers faster speed but mandates voltage redesign and forfeits military qualification, while CY62128EV30LL-45ZSXI trades access time and environmental robustness for lower procurement cost in non-safety-critical roles.
Availability
71256L35DB is available at Aetrix Electronics and suitable for avionics flight control units, tactical radio transceivers, missile guidance systems, and armored vehicle C4ISR terminals requiring stable component supply across extended product lifecycles.
Supply support for 71256L35DB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Renesas Electronics Corporation is a global semiconductor leader specializing in microcontrollers, analog, power, and memory solutions for automotive, industrial, and aerospace markets.
The 71256L series was designed specifically for high-reliability military and aerospace applications demanding extended temperature operation, hermetic packaging, and battery-backed data integrity without external support circuitry.
FAQ
What is the maximum operating temperature range for the 71256L35DB?
The 71256L35DB is rated for continuous operation from –55°C to +125°C, meeting MIL-STD-883 Class B environmental screening requirements for airborne and ground vehicle platforms. This range is validated across all AC and DC electrical parameters in the datasheet, including 35ns access time and 3mA standby current.
Does the 71256L35DB support true battery backup operation?
Yes, the 71256L35DB supports true battery backup: it retains stored data at VCC as low as 2.0V across its full military temperature range, consuming only 5μW typical in this mode. No external circuitry is needed-the device automatically enters retention mode when VCC drops below operational threshold.
Is the 71256L35DB pin-compatible with other members of the 71256 family?
Yes, the 71256L35DB shares identical pinout and footprint with all 71256S/L variants in the CD28 (600-mil ceramic DIP) package, including 71256S25DB, 71256L25DB, and 71256S35DB. Signal assignments, power pins, and timing control logic are functionally identical across speed grades and power variants.
What package type does the 71256L35DB use, and is it RoHS-compliant?
The 71256L35DB uses a 28-pin 600-mil ceramic dual in-line package (CD28), which is hermetically sealed and MIL-STD-883 qualified. Per Renesas' ordering information, "Green" versions are available-these meet RoHS Directive 2011/65/EU and are marked with "G" suffix in orderable part numbers.
How does the standby power consumption of the 71256L35DB compare to standard SRAMs?
The 71256L35DB draws just 3mA in TTL-level standby (ISB) and 1.5mA in CMOS-level standby (ISB1), representing >97% reduction versus its active current of 115mA. This is achieved through internal power-gating architecture activated solely by CS high, eliminating need for external sleep controllers.
71256L35DB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 28-CDIP (0.600", 15.24mm)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Volatile
- Memory Format:
- SRAM
- Technology:
- SRAM - Asynchronous
- Memory Size:
- 256Kbit
- Memory Organization:
- 32K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- 35ns
- Access Time:
- 35 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -55°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 28-CDIP
71256L35DB FAQ
1.How can I place an order for 71256L35DB through Aetrix?
Please submit a Request for Quotation (RFQ) for 71256L35DB on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for 71256L35DB reliable?
The price and inventory of 71256L35DB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71256L35DB is usually 5 days.
3.What payment methods are accepted for 71256L35DB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71256L35DB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71256L35DB?
71256L35DB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71256L35DB order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for 71256L35DB?
For technical support, including 71256L35DB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71256L35DB requirements.
6.How does Aetrix verify that 71256L35DB is sourced from the original manufacturer or authorized distributors?
All 71256L35DB products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 71256L35DB meets industry standards.
7.What is the process for return or replacement of 71256L35DB?
All 71256L35DB units undergo pre-shipment inspection (PSI). If there is an issue with 71256L35DB, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The 71256L35DB part is unused and in its original packaging.
Return procedure for 71256L35DB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71256L35DB Tags
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AT24C02C-XHM-T
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