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Renesas 71256L70DB
- Part No.:
- 71256L70DB
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-CDIP (0.600", 15.24mm)
- Datasheet:
-
71256L70DB.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28CDIP
- Quantity:
- Payment:
- Shipping:
Inventory:2,028
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Product details
Overview
71256L70DB from Renesas Electronics is a 256K (32K × 8-bit) low-power CMOS static RAM with military-grade reliability, 70 ns access time, 5 V supply, and –55°C to +125°C operating range. It features battery backup data retention at 2 V, TTL-compatible I/O, and automatic standby mode triggered by chip select high. Used in avionics control modules requiring nonvolatile SRAM with radiation-tolerant timing stability.
For engineers reviewing the 71256L70DB datasheet, 71256L70DB pinout, 71256L70DB application, or 71256L70DB equivalent, key selection criteria include military temperature compliance, 2 V data retention capability, 70 ns read cycle time under full military grade conditions, and ceramic DIP package mechanical robustness for high-vibration environments.
Technical Context
The 71256L70DB implements a fully static memory array with asynchronous parallel interface, using high-reliability CMOS process qualified to MIL-STD-883 Class B. Its control logic supports CS/WE/OE three-strobe operation with separate read and write timing paths, and automatic transition to low-power standby when CS is deasserted.
It delivers 70 ns address access time (tAA), 70 ns read cycle time (tRC), and 70 ns write cycle time (tWC) across the full –55°C to +125°C range. Standby current is 1.5 mA typical at VCC = 5.5 V, and data retention draws only 800 µA max at 2.0 V - enabling long-term backup without external regulators.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144 bits), byte-wide parallel interface |
| Access Time (tAA) | 70 ns max over –55°C to +125°C - guarantees deterministic read latency in real-time flight control systems |
| Supply Voltage | 5.0 V ±10% (4.5–5.5 V) - compatible with standard military 5 V power rails |
| Data Retention Voltage | 2.0 V min - enables direct connection to backup lithium battery without voltage regulation |
| Standby Current (ISB1) | 1.5 mA max at VCC = 5.5 V, CMOS-level CS - reduces system idle power by >95% vs active mode |
| Operating Temperature | –55°C to +125°C - qualified per MIL-STD-883 Class B for deployment in engine-mounted or space-constrained avionics |
| Package Type | 28-pin 600 mil ceramic DIP (CD28) - hermetically sealed, leaded, high thermal mass for thermal shock resistance |
Pinout & Package
71256L70DB is housed in a 28-pin 600 mil ceramic dual in-line package (CD28), featuring hermetic sealing, gold-plated leads, and MIL-STD-883-compliant construction for extended life in harsh environments.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus supporting full 32K-word decoding; TTL-compatible thresholds ensure noise margin in noisy platforms |
| I/O0–I/O7 | Bi-directional Data Bus | 8-bit parallel data path with 3-state outputs; supports simultaneous read/write handshaking via OE/WE |
| CS | Chip Select | Active-low enable; drives device into 1.5 mA standby mode when high - critical for power-gating in multi-SRAM systems |
| WE | Write Enable | Active-low write strobe; controls write cycle timing (tWP ≥ 45 ns) and disables outputs during write to prevent bus contention |
| OE | Output Enable | Active-low output control; allows multiplexed bus sharing without external transceivers |
| VCC | Power Supply | +5 V supply pin; decoupling required within 10 mm due to fast switching currents (ICC = 115 mA typ.) |
| GND | Ground Reference | Signal and power ground return; must be connected to low-impedance plane to maintain 0.4 V VOL under 10 mA load |
Key Features
| Feature | Design Value |
|---|---|
| Battery backup data retention | Operates down to 2.0 V with ≤800 µA ICCDR - eliminates need for external retention regulators in mission-critical black-box recorders |
| MIL-STD-883 Class B qualification | Fully tested per Method 5005, 5007, 5011 - ensures reliability in launch vibration, thermal cycling, and radiation-prone aerospace deployments |
| Low-power standby mode | 1.5 mA ISB1 at VCC = 5.5 V - enables >10× reduction in quiescent power vs active operation for dormant subsystems |
| TTL-compatible I/O | VIH = 2.2 V min, VIL = 0.8 V max - interoperable with legacy 5 V microcontrollers and FPGAs without level shifters |
| Hermetic ceramic DIP packaging | CD28 footprint (600 mil width) with glass-sealed leads - prevents moisture ingress and provides superior thermal dissipation vs plastic packages |
Applications
| Avionics Flight Data Recorder | Tactical Radio Baseband Buffer |
|---|---|
|
Use Scenario: Continuous buffering of sensor telemetry and navigation state during powered operation, with seamless retention during main power loss. IC Role / Device Role / Timing Role: Primary volatile buffer with battery-backed retention; serves as last-write cache before nonvolatile flash commit. Use Value: 70 ns tAA ensures no data loss during 10 kHz sampling bursts; 2 V retention sustains 30+ days on coin cell without recharge circuitry. |
Use Scenario: Real-time modulation/demodulation data staging between FPGA baseband processor and RF transceiver IC. IC Role / Device Role / Timing Role: Synchronous FIFO replacement with deterministic 70 ns read/write latency and zero wait-state operation. Use Value: TTL-compatible I/O eliminates level-shifting components; MIL-temp rating supports operation inside sealed radio chassis exposed to desert or arctic extremes. |
| Missile Guidance Control Memory | Spacecraft Onboard Telemetry Cache |
|
Use Scenario: Storing guidance algorithm coefficients and inertial measurement updates during boost phase where power may fluctuate. IC Role / Device Role / Timing Role: High-reliability scratchpad memory interfaced directly to radiation-hardened microcontroller. Use Value: MIL-STD-883 Class B qualification validates survivability under 10,000 g shock; 70 ns tRC enables closed-loop control loop execution < 100 µs. |
Use Scenario: Temporary storage of science instrument readings prior to downlink compression and transmission during orbital eclipse periods. IC Role / Device Role / Timing Role: Low-power buffer retaining data across 90-minute eclipse cycles using onboard battery bus. Use Value: 800 µA max ICCDR at 2 V extends eclipse survival time by >40% vs standard SRAM; CD28 package resists atomic oxygen erosion in LEO. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar static RAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| IS61LV25616AL-70TQLI | 32K × 16-bit organization, 3.3 V supply, 70 ns access, 100-pin TQFP - higher density but incompatible voltage and bus width | Requires level translation and data bus remapping; unsuitable for drop-in replacement in 5 V, 8-bit legacy designs | Select only if upgrading to 3.3 V architecture and needing wider data path; not suitable for 71256L70DB footprint or voltage domain. |
| CY62256LN-70ZSXI | 32K × 8-bit, 5 V, 70 ns, SOIC-28 package - same speed and organization but plastic package, industrial temp only (–40°C to +85°C) | Lacks MIL-STD-883 qualification and hermetic sealing; cannot meet avionics or missile environmental requirements | Acceptable for commercial/industrial embedded systems where cost and board space outweigh military reliability needs. |
Compared with IS61LV25616AL-70TQLI and CY62256LN-70ZSXI, the 71256L70DB uniquely combines military temperature range, ceramic DIP packaging, 2 V data retention, and MIL-STD-883 Class B qualification - making it irreplaceable in safety-critical aerospace hardware where failure modes are non-negotiable.
Availability
71256L70DB is available at Aetrix Electronics and suitable for avionics flight data recorders, tactical radio baseband buffers, and missile guidance control systems requiring stable component supply across extended production lifecycles and extreme environmental certification.
Supply support for 71256L70DB 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 infrastructure markets.
The 71256L70DB belongs to Renesas' legacy high-reliability SRAM product line, designed specifically for defense, aerospace, and industrial applications demanding MIL-qualified performance, long-term obsolescence support, and hermetic packaging integrity.
FAQ
What is the maximum operating temperature range for the 71256L70DB?
The 71256L70DB is rated for operation from –55°C to +125°C and is fully qualified to MIL-STD-883 Class B. This specification is verified across all AC and DC parameters in the datasheet, including 70 ns access time and 1.5 mA standby current, ensuring guaranteed performance in engine bays, missile canisters, and space-rated enclosures.
Does the 71256L70DB support true battery backup operation below 5 V?
Yes - the 71256L70DB supports data retention at 2.0 V minimum (VDR), drawing ≤800 µA typical. This is explicitly specified in Table 11 of the datasheet and validated across military temperature ranges, enabling direct connection to 2 V lithium batteries without regulator circuitry.
Is the 71256L70DB pin-compatible with other members of the 71256 family?
Yes - the 71256L70DB shares identical pinout and package (CD28) with all 71256S/L variants in 600 mil ceramic DIP, including 71256S70DB and 71256L55DB. Signal assignments, power/ground locations, and timing control logic are functionally identical; only speed grade and power class differ.
What package type does the 71256L70DB use, and why is it significant?
The 71256L70DB uses a 28-pin 600 mil ceramic DIP (CD28) package. This hermetically sealed, leaded package meets MIL-STD-883 mechanical and environmental test requirements, offering superior moisture resistance, thermal stability, and long-term reliability compared to plastic SOIC or SOJ alternatives - essential for aerospace and defense deployments.
How does the standby power mode work on the 71256L70DB?
The 71256L70DB enters low-power standby automatically when CS is driven HIGH. In full standby (ISB1 mode), it draws only 1.5 mA max at VCC = 5.5 V. This feature is implemented in silicon and verified across temperature - enabling system-level power savings without firmware intervention or external control logic.
71256L70DB 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:
- 70ns
- Access Time:
- 70 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
71256L70DB FAQ
1.How can I place an order for 71256L70DB through Aetrix?
Please submit a Request for Quotation (RFQ) for 71256L70DB 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 71256L70DB reliable?
The price and inventory of 71256L70DB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71256L70DB is usually 5 days.
3.What payment methods are accepted for 71256L70DB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71256L70DB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71256L70DB?
71256L70DB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71256L70DB 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 71256L70DB?
For technical support, including 71256L70DB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71256L70DB requirements.
6.How does Aetrix verify that 71256L70DB is sourced from the original manufacturer or authorized distributors?
All 71256L70DB 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 71256L70DB meets industry standards.
7.What is the process for return or replacement of 71256L70DB?
All 71256L70DB units undergo pre-shipment inspection (PSI). If there is an issue with 71256L70DB, 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 71256L70DB part is unused and in its original packaging.
Return procedure for 71256L70DB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71256L70DB Tags
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M24C02-WMN6TP
STMicroelectronics
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AT24C02C-XHM-T
Microchip Technology
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AT21CS01-STUM10-T
Microchip Technology
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AT24C02C-SSHM-T
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24LC01BT-I/OT
Microchip Technology
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M24C02-FMC6TG
STMicroelectronics
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AT24CS02-SSHM-T
Microchip Technology
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93LC46BT-I/OT
Microchip Technology
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AT24C04C-SSHM-T
Microchip Technology
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24LC01BT-I/SN
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24AA02UIDT-I/OT
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AT24C08C-STUM-T
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