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Renesas 71256L100TDB
- Part No.:
- 71256L100TDB
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-CDIP (0.300", 7.62mm)
- Datasheet:
-
71256L100TDB.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28CDIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,921
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Product details
Overview
71256L100TDB from Renesas is a 256K-bit (32K × 8) low-power CMOS static RAM with military-grade reliability, 100ns max access time, –55°C to +125°C operating range, and 2V battery backup data retention. It serves as nonvolatile system memory in avionics control units, radar signal buffers, and hardened telemetry recorders where power loss resilience and extended temperature operation are critical.
For engineers reviewing the 71256L100TDB datasheet, 71256L100TDB pinout, 71256L100TDB application, or 71256L100TDB equivalent, key selection criteria include military-qualified timing consistency across full temperature range, TTL-compatible I/O interface, standby current of 1.5mA at VCC = 5.5V, and ceramic DIP package compatibility with legacy high-reliability PCB layouts.
Technical Context
This device implements a fully decoded 15-bit address space (A0–A14) driving a 32K × 8-bit memory array using high-reliability CMOS process. Its dual standby modes-TTL-level (ISB = 3mA) and CMOS-level (ISB1 = 1.5mA)-are triggered by CS logic level, enabling precise system-level power gating without external sequencing.
The 71256L100TDB supports WE-controlled and CS-controlled write cycles with defined tDW (40ns), tWP (55ns), and tWHZ (40ns) parameters, ensuring deterministic bus arbitration in synchronous digital systems. All AC timing parameters-including tAA, tACS, and tRC-are guaranteed over the full –55°C to +125°C range per MIL-STD-883 Class B.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144 bits), single-port parallel SRAM |
| Access Time (tAA) | 100ns max at –55°C to +125°C; enables synchronization with 10MHz system clocks |
| Supply Voltage | 5.0V ±10% (4.5–5.5V); compatible with standard TTL/CMOS logic rails |
| Standby Current (ISB1) | 1.5mA max at VCC = 5.5V, CMOS-level CS; reduces idle power in battery-backed systems |
| Data Retention | 2.0V min VCC; retains contents during brownout or main supply failure |
| Operating Temperature | –55°C to +125°C; qualified per MIL-STD-883 Class B for mission-critical deployment |
| I/O Compatibility | TTL-input and TTL-output levels; eliminates level-shifter requirements in mixed-logic designs |
Pinout & Package
71256L100TDB uses a 28-pin 300-mil ceramic dual in-line package (CERDIP), designated SD28 in Renesas ordering nomenclature. This hermetically sealed package ensures long-term reliability in high-humidity, high-vibration, and radiation-prone environments typical of aerospace and defense platforms.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit unidirectional address bus; fully decoded to select one of 32,768 memory locations |
| I/O0–I/O7 | Bi-directional Data Bus | 8-bit shared input/output path; high-impedance when CS or OE inactive |
| CS | Chip Select | Active-low enable; controls entry into standby mode (ISB/ISB1) when deasserted |
| WE | Write Enable | Active-low write strobe; determines write cycle timing (tWP, tDW) and bus direction |
| OE | Output Enable | Active-low output gate; isolates data bus during reads when CS is active |
| VCC | Power Supply | +5V ±10% main supply; powers core logic and I/O drivers |
| GND | Ground Reference | Signal and power return; requires low-impedance connection to minimize noise coupling |
Key Features
| Feature | Design Value |
|---|---|
| Battery backup data retention | Operates down to 2.0V VCC with ≤800μA ICCDR, enabling seamless transition to backup power without data loss |
| MIL-STD-883 Class B compliance | Full screening including thermal cycling, mechanical shock, and burn-in ensures field reliability in harsh operational environments |
| Dual standby current modes | ISB = 3mA (TTL CS threshold) and ISB1 = 1.5mA (CMOS CS threshold) allow flexible system power management strategies |
| Hermetic ceramic DIP packaging | SD28 300-mil CERDIP provides moisture resistance, thermal stability, and long-term solder joint integrity |
| Guaranteed AC timing over full temp range | All read/write parameters (tRC, tWC, tOE, tCHZ) specified at –55°C/+125°C - no derating required |
Applications
| Avionics Flight Control Memory | Radar Signal Buffering |
|---|---|
Use Scenario: Stores real-time sensor fusion outputs and actuator command history in fly-by-wire flight computers. IC Role / Device Role / Timing Role: Nonvolatile shadow RAM holding critical state variables during transient power interruptions. Use Value: 2V data retention ensures zero data loss during engine start-up voltage sag or generator fault conditions. |
Use Scenario: Buffers digitized RF echo samples between ADC capture and FFT processing in pulse-Doppler radar front ends. IC Role / Device Role / Timing Role: High-speed parallel SRAM providing deterministic 100ns read/write latency for time-critical sample streaming. Use Value: Guaranteed tAA ≤100ns across –55°C to +125°C eliminates timing margin uncertainty in wide-temperature airborne deployments. |
| Secure Telemetry Recorder | Hardened Industrial PLC Module |
Use Scenario: Captures encrypted mission telemetry streams in satellite payload subsystems with periodic downlink. IC Role / Device Role / Timing Role: Battery-backed memory preserving last-known valid state and encrypted logs during orbital eclipse periods. Use Value: 1.5mA ISB1 current at full temperature range extends backup battery life beyond 10 years in low-duty-cycle recording. |
Use Scenario: Holds firmware configuration tables and I/O mapping registers in nuclear plant safety-rated programmable logic controllers. IC Role / Device Role / Timing Role: MIL-B-qualified SRAM serving as deterministic configuration store immune to EMI-induced bit flips. Use Value: Hermetic CERDIP packaging and MIL-STD-883 screening prevent latent failures in high-radiation, high-vibration reactor environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-reliability SRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY62256LN-100ZSXI | 100ns access, 32K × 8, SOIC-28, industrial temp only (–40°C to +85°C) | Lacks MIL-STD-883 qualification and battery backup capability | Use only in commercial/industrial systems where military screening and 2V retention are not required |
| AS6C4008-100TIN | 100ns access, 512K × 8, TSSOP-32, industrial temp, no battery backup | Higher density but incompatible pinout and package; no military qualification or data retention | Select only when board redesign permits larger footprint and higher capacity is needed without retention or screening |
Compared with CY62256LN-100ZSXI and AS6C4008-100TIN, the 71256L100TDB uniquely delivers MIL-STD-883 Class B screening, 2V battery backup, and hermetic CERDIP packaging - making it irreplaceable in applications demanding guaranteed operation under extreme environmental stress and power continuity.
Availability
71256L100TDB is available at Aetrix Electronics and suitable for avionics flight control, radar signal buffering, and secure telemetry recording requiring stable component supply across extended product lifecycles and obsolescence-sensitive programs.
Supply support for 71256L100TDB 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 71256L100TDB belongs to Renesas' legacy high-reliability SRAM product line, designed specifically for military, aerospace, and safety-critical industrial applications demanding guaranteed performance across extreme temperature and voltage conditions.
FAQ
What is the maximum operating temperature range for the 71256L100TDB?
The 71256L100TDB is rated for continuous operation from –55°C to +125°C and is fully qualified per MIL-STD-883 Class B. All AC and DC electrical specifications - including tAA = 100ns, ISB1 = 1.5mA, and VDR = 2.0V - are guaranteed across this full military temperature range without derating.
Does the 71256L100TDB support true battery backup operation?
Yes, the 71256L100TDB supports true battery backup: it retains stored data at VCC as low as 2.0V with ICCDR ≤800μA across all temperatures. This capability is intrinsic to the "L" (low-power) variant and is verified in Table 11 of the Renesas datasheet under Data Retention Characteristics.
What package type does the 71256L100TDB use, and is it lead-free?
The 71256L100TDB uses a 28-pin 300-mil ceramic dual in-line package (CERDIP), identified as SD28 in Renesas ordering codes. Per the August 2020 datasheet revision, "Green parts available" confirms RoHS-compliant, lead-free terminations - verified in the Ordering Information section (page 9).
How does the 71256L100TDB enter low-power standby mode?
The 71256L100TDB enters standby automatically when CS is driven HIGH. At TTL-level thresholds (CS > VIH), it draws ISB = 3mA; at CMOS-level thresholds (CS > VHC), it draws the lower ISB1 = 1.5mA. Both states maintain full data integrity and require no additional control signals or sequencing.
Is the 71256L100TDB pin-compatible with other members of the 71256 family?
Yes, all 71256S/L variants - including 71256L100TDB - share identical 28-pin SD28 CERDIP pinout and functional assignment (A0–A14, I/O0–I/O7, CS, WE, OE, VCC, GND). Speed grade differences (20ns to 100ns) and power variants (S vs L) do not affect pin compatibility or interface behavior.
71256L100TDB 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:
- 100ns
- Access Time:
- 100 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
71256L100TDB FAQ
1.How can I place an order for 71256L100TDB through Aetrix?
Please submit a Request for Quotation (RFQ) for 71256L100TDB 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 71256L100TDB reliable?
The price and inventory of 71256L100TDB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71256L100TDB is usually 5 days.
3.What payment methods are accepted for 71256L100TDB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71256L100TDB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71256L100TDB?
71256L100TDB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71256L100TDB 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 71256L100TDB?
For technical support, including 71256L100TDB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71256L100TDB requirements.
6.How does Aetrix verify that 71256L100TDB is sourced from the original manufacturer or authorized distributors?
All 71256L100TDB 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 71256L100TDB meets industry standards.
7.What is the process for return or replacement of 71256L100TDB?
All 71256L100TDB units undergo pre-shipment inspection (PSI). If there is an issue with 71256L100TDB, 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 71256L100TDB part is unused and in its original packaging.
Return procedure for 71256L100TDB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71256L100TDB Tags
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