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Renesas 71256L70TDB
- Part No.:
- 71256L70TDB
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-CDIP (0.300", 7.62mm)
- Datasheet:
-
71256L70TDB.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28CDIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,803
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Product details
Overview
71256L70TDB from Renesas Electronics is a 256K (32K × 8-bit) high-speed CMOS static RAM with military-grade reliability, 70 ns access time, -55°C to +125°C operating temperature range, and low-power standby current of 1.5 mA (typ.). It serves as non-volatile data buffer in avionics control units requiring deterministic timing and battery-backed retention.
For engineers reviewing the 71256L70TDB datasheet, 71256L70TDB pinout, 71256L70TDB application, or 71256L70TDB equivalent, key selection criteria include military-qualified SOJ/DIP packaging, 2V data retention capability, TTL-compatible I/O, and MIL-STD-883 Class B compliance for harsh-environment embedded systems.
Technical Context
The 71256L70TDB implements a full CMOS static memory array with asynchronous parallel interface, supporting independent read/write cycles via separate CS, WE, and OE controls. Its architecture enables zero-wait-state operation at 70 ns tAA and tACS under military temperature extremes.
It features dual standby modes: TTL-level standby (ISB1 = 1.5 mA @ VCC = 5.5 V) triggered by CS > VHC, and battery backup mode (ICCDR ≤ 200 μA @ VDR = 2.0 V) enabling data retention during main power loss - both validated across -55°C to +125°C.
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 - guarantees deterministic read latency in real-time flight control loops |
| Supply Voltage | 5.0 V ± 10% - compatible with standard military 5V rail without regulation overhead |
| Operating Temperature | -55°C to +125°C - qualified per MIL-STD-883 Class B for airborne/spaceborne deployment |
| Data Retention Voltage | 2.0 V min - sustains memory state from backup battery during primary power failure |
| Standby Current (ISB1) | 1.5 mA max @ VCC = 5.5 V - reduces system-level cooling load in sealed avionics enclosures |
| I/O Compatibility | TTL input thresholds (VIH = 2.2 V, VIL = 0.8 V) and output drive (VOL = 0.4 V @ 8 mA) - interoperable with legacy 5V logic families |
Pinout & Package
71256L70TDB is supplied in a 28-pin 300-mil ceramic dual in-line package (CDIP), designated SD28 in Renesas ordering nomenclature. This hermetically sealed package ensures long-term reliability in high-humidity, high-vibration aerospace environments.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus supporting full 32K-word addressing; CMOS inputs with 11 pF max capacitance |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit TTL-compatible data path; high-impedance when CS or OE inactive; supports read/write multiplexing |
| CS | Chip Select | Active-low enable controlling device activation and automatic entry into low-power standby (ISB1) when high |
| WE | Write Enable | Active-low signal initiating write cycle; controls data latching and disables outputs during write |
| OE | Output Enable | Active-low control for output drivers; allows read data to appear on I/O pins only when asserted |
| VCC | Power Supply | +5 V ± 10% supply pin; supports up to 1.0 W total power dissipation |
| GND | Ground Reference | Signal and power ground reference; required for stable DC bias and noise margin |
Key Features
| Feature | Design Value |
|---|---|
| MIL-STD-883 Class B qualification | Fully tested to military screening standards including burn-in, temperature cycling, and hermeticity - eliminates need for additional qualification testing in defense programs |
| 2V data retention mode | Retains stored data with ≤200 μA current draw from 2.0 V battery source - enables seamless failover in mission-critical black-box recorders |
| Low-power standby (ISB1) | 1.5 mA typical consumption in full CMOS standby - reduces thermal load in densely packed avionics line-replaceable units (LRUs) |
| TTL-compatible I/O | Direct interface with legacy 5V microcontrollers and FPGAs without level-shifting circuitry - simplifies board design and improves signal integrity |
| 70 ns military-grade speed | Guaranteed tAA and tACS ≤ 70 ns over full -55°C to +125°C range - meets hard real-time deadlines in radar pulse processing subsystems |
Applications
| Avionics Flight Control Unit | Tactical Radio Baseband Processor |
|---|---|
|
Use Scenario: Real-time servo command buffering and sensor fusion data staging in fly-by-wire systems. IC Role / Device Role / Timing Role: High-reliability scratchpad RAM holding actuator position history and PID loop coefficients. Use Value: 70 ns access ensures sub-millisecond response to airframe instability events; MIL-STD-883 qualification guarantees operation during rapid thermal transients. |
Use Scenario: Intermediate frequency (IF) sample storage and modulation parameter caching in software-defined radios. IC Role / Device Role / Timing Role: Low-latency, battery-backed memory for waveform configuration tables and channel equalization coefficients. Use Value: 2V data retention preserves radio settings during battery swap; 1.5 mA ISB1 minimizes standby drain in manpack deployments. |
| Spacecraft Onboard Computer Cache | Missile Guidance Inertial Measurement Unit |
|
Use Scenario: Non-volatile storage of boot firmware checksums and telemetry history in radiation-tolerant satellite subsystems. IC Role / Device Role / Timing Role: Radiation-hardened-adjacent SRAM used for critical state snapshotting prior to safe-mode entry. Use Value: Ceramic DIP package resists outgassing in vacuum; -55°C to +125°C rating covers orbital thermal extremes without derating. |
Use Scenario: Gyro/accelerometer calibration coefficient storage and real-time navigation vector accumulation. IC Role / Device Role / Timing Role: Deterministic-access memory for Kalman filter state variables updated at 1 kHz. Use Value: 70 ns tAA enables full 32K-word update within 2.2 ms - meeting guidance loop timing budgets under high-g launch conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-reliability static RAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| IS61LV25616AL-70TQLI | 32K × 16-bit organization, 3.3 V supply, 70 ns access, commercial/industrial temp only (-40°C to +85°C) | Lacks MIL-STD-883 qualification and 2V data retention; suitable for ground-based test equipment but not flight hardware | Select only for cost-sensitive terrestrial industrial controllers where military certification is unnecessary |
| CY62256LN-70ZSXI | 32K × 8-bit, 5 V supply, 70 ns access, industrial temp (-40°C to +85°C), no battery backup mode | No data retention below 4.5 V; unqualified for military environments; lower screening rigor than MIL-STD-883 Class B | Acceptable for ruggedized but non-mission-critical embedded systems such as vehicle ECUs with extended temp requirements |
Compared with IS61LV25616AL-70TQLI and CY62256LN-70ZSXI, the 71256L70TDB uniquely delivers MIL-STD-883 Class B qualification, guaranteed -55°C to +125°C operation, and 2V battery-backed data retention - making it the sole option for certified airborne and spaceflight applications requiring full environmental and reliability assurance.
Availability
71256L70TDB is available at Aetrix Electronics and suitable for avionics flight control units, tactical radio baseband processors, spacecraft onboard computers, and missile guidance inertial measurement units requiring stable component supply across extended product lifecycles.
Supply support for 71256L70TDB 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 71256L70TDB belongs to Renesas' legacy high-reliability static RAM product line, engineered specifically for military, aerospace, and industrial applications demanding guaranteed performance across extreme temperatures and long-term operational stability.
FAQ
What is the maximum operating temperature range for the 71256L70TDB?
The 71256L70TDB is rated for continuous operation from -55°C to +125°C and is fully qualified to MIL-STD-883 Class B screening requirements. This range is verified across all AC and DC parameters including access time, standby current, and data retention - making it suitable for engine-mounted avionics and space-rated electronics where thermal extremes are routine.
Does the 71256L70TDB support battery backup operation, and what voltage is required?
Yes, the 71256L70TDB supports battery backup data retention at VDR ≥ 2.0 V, consuming ≤ 200 μA typical current. This mode maintains stored data indefinitely while main VCC is removed - a critical feature for black-box recorders and fault-logging systems in defense platforms where power interruption must not cause memory loss.
Is the 71256L70TDB pin-compatible with other members of the 71256 family?
Yes, the 71256L70TDB shares identical 28-pin SD28 CDIP pinout and signal definitions with all 71256S/L variants in the same package type, including 71256L55TDB and 71256L85TDB. Address, data, and control pin assignments are functionally identical - enabling speed-bin upgrades without PCB redesign.
What is the standby current specification for the 71256L70TDB, and how is it triggered?
The 71256L70TDB draws 1.5 mA maximum standby current (ISB1) when CS is held above VHC (VCC − 0.2 V) with no address transitions. This full CMOS standby mode is automatically entered and maintained as long as CS remains high - providing predictable power savings in intermittently active subsystems like telemetry transmitters.
Which package type does the 71256L70TDB use, and what are its mechanical identifiers?
The 71256L70TDB uses a 28-pin 300-mil ceramic dual in-line package (CDIP), identified by Renesas as SD28. Its body dimensions are 0.900" × 0.300", with 0.100" lead spacing and hermetic ceramic construction - ensuring moisture resistance and mechanical robustness in high-vibration military platforms.
71256L70TDB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 28-CDIP (0.300", 7.62mm)
- 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
71256L70TDB FAQ
1.How can I place an order for 71256L70TDB through Aetrix?
Please submit a Request for Quotation (RFQ) for 71256L70TDB 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 71256L70TDB reliable?
The price and inventory of 71256L70TDB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71256L70TDB is usually 5 days.
3.What payment methods are accepted for 71256L70TDB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71256L70TDB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71256L70TDB?
71256L70TDB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71256L70TDB 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 71256L70TDB?
For technical support, including 71256L70TDB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71256L70TDB requirements.
6.How does Aetrix verify that 71256L70TDB is sourced from the original manufacturer or authorized distributors?
All 71256L70TDB 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 71256L70TDB meets industry standards.
7.What is the process for return or replacement of 71256L70TDB?
All 71256L70TDB units undergo pre-shipment inspection (PSI). If there is an issue with 71256L70TDB, 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 71256L70TDB part is unused and in its original packaging.
Return procedure for 71256L70TDB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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