My Inquiry
My Account
Renesas 71256L45DB
- Part No.:
- 71256L45DB
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-CDIP (0.600", 15.24mm)
- Datasheet:
-
71256L45DB.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28CDIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,246
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
71256L45DB from Renesas Electronics is a 256K (32K × 8-bit) low-power CMOS static RAM with military-grade reliability, 45ns maximum access time, 2V data retention capability, and compliance with MIL-STD-883 Class B. It operates across –55°C to +125°C and delivers 1.5mA standby current in full CMOS-level standby mode, serving as nonvolatile memory backup in avionics and ruggedized control systems.
For engineers reviewing the 71256L45DB datasheet, 71256L45DB pinout, 71256L45DB application, or 71256L45DB equivalent, key selection criteria include military temperature support, battery-backed data retention at 2V, TTL-compatible I/O, ceramic DIP packaging, and verified 45ns read/write timing under worst-case conditions.
Technical Context
The 71256L45DB implements a fully static memory array with asynchronous parallel interface, using high-reliability CMOS process technology. Its dual standby modes-TTL-level (ISB = 3mA) and CMOS-level (ISB1 = 1.5mA)-are triggered by chip select (CS) logic level, enabling system-level power optimization without external control logic.
It supports WE-controlled and CS-controlled write cycles with defined setup/hold timing (tAS = 0ns, tDH = 0ns), features TTL-compatible input thresholds (VIH = 2.2V min, VIL = 0.8V max), and guarantees data retention down to 2.0V supply while drawing ≤800μA ICCDR across all military temperatures.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144-bit total), byte-wide parallel interface |
| Access Time (tAA) | 45ns max at –55°C to +125°C, enabling real-time data buffering in deterministic systems |
| 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 disable, reducing idle power in battery-critical designs |
| Data Retention Voltage | 2.0V min, allowing operation from single-cell lithium or backup coin cells without regulation |
| Input/Output Compatibility | TTL-compatible inputs (VIH ≥ 2.2V, VIL ≤ 0.8V); outputs drive ±10mA loads |
| Operating Temperature | –55°C to +125°C, qualified per MIL-STD-883 Class B for mission-critical deployment |
Pinout & Package
71256L45DB is housed in a 28-pin 600-mil ceramic dual in-line package (CDIP, code CD28), rated for high-reliability military environments and offering hermetic sealing and thermal stability.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus supporting full 32K-word addressing; no internal latching |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit TTL-compatible data path; high-impedance when CS or OE inactive |
| CS | Chip Select | Active-low enable; controls entry into standby (ISB/ISB1) and memory activation |
| WE | Write Enable | Active-low signal defining write cycle boundaries; enables data capture on falling edge |
| OE | Output Enable | Active-low control for output drivers; independent of CS/WE for flexible bus sharing |
| VCC | Power Supply | 5V ±10% main supply; powers core logic and I/O buffers |
| GND | Ground Reference | Common return for all signals and power; decoupling required per MIL-STD-883 layout rules |
Key Features
| Feature | Design Value |
|---|---|
| Low-power standby (ISB1) | 1.5mA max at VCC = 5.5V enables >1-year battery backup with standard 2V lithium cells |
| 2V data retention | Guaranteed data hold at 2.0V supply across full –55°C to +125°C range, eliminating need for voltage supervisors |
| MIL-STD-883 Class B compliance | Qualified for shock, vibration, temperature cycling, and hermeticity per military screening standards |
| TTL-compatible I/O | Direct interface with legacy 5V microcontrollers and FPGAs without level-shifting circuitry |
| Two standby modes | Configurable ISB (TTL-level CS) and ISB1 (CMOS-level CS) for optimal power vs. wake-up latency trade-off |
Applications
| Avionics Flight Data Recorder | Tactical Radio Baseband Buffer |
|---|---|
Use Scenario: Continuous logging of inertial navigation and sensor telemetry during powered flight and post-crash survival mode. IC Role / Device Role / Timing Role: Nonvolatile SRAM buffer retaining critical last-minute data when main power fails and 2V backup sustains memory. Use Value: Meets DO-160E Section 22 crash survivability requirements via guaranteed 2V data retention and MIL-STD-883 qualification. |
Use Scenario: Real-time modulation/demodulation data buffering in software-defined radios operating in extreme ambient temperatures. IC Role / Device Role / Timing Role: High-speed parallel memory interfacing directly with FPGA-based baseband processors under –55°C to +125°C conditions. Use Value: 45ns access time ensures zero-cycle wait states at 10MHz bus rates; ceramic DIP withstands thermal shock during rapid field deployment. |
| Missile Guidance System Memory | Ruggedized Industrial PLC Module |
Use Scenario: Storing guidance coefficients and trajectory updates during launch acceleration and sustained hypersonic flight. IC Role / Device Role / Timing Role: Mission-critical storage element with deterministic 45ns read/write timing and radiation-tolerant CMOS process. Use Value: MIL-STD-883 Class B qualification ensures immunity to mechanical stress and thermal transients exceeding 20g and 50°C/min ramp rates. |
Use Scenario: Retaining configuration and fault-history data in oilfield control cabinets exposed to wide thermal swings and EMI. IC Role / Device Role / Timing Role: Battery-backed memory preserving state during brownouts, with direct TTL interface to legacy 8051-based controllers. Use Value: 1.5mA ISB1 current extends backup battery life to >5 years; ceramic package resists moisture ingress per IP67 enclosure requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar static RAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 71256S45DB | Standard-power variant (ISB1 = 20mA vs. 1.5mA); identical timing, package, and temperature rating | Lacks 2V data retention; requires regulated 5V supply only | Select when lowest standby power is not required and system already provides stable 5V rail |
| IS61LV256AL-10TLI | 3.3V-only supply (3.0–3.6V), 10ns access, SOJ-28; no MIL-STD-883 qualification or 2V retention | Designed for commercial/industrial embedded systems, not military environments | Choose for cost-sensitive, non-military designs requiring faster access and lower voltage operation |
Compared with 71256S45DB, the 71256L45DB reduces standby current by 93% enabling true battery backup; compared with IS61LV256AL-10TLI, it trades speed and voltage flexibility for MIL-qualified reliability and 2V retention-critical for unregulated, long-duration, high-stress deployments.
Availability
71256L45DB is available at Aetrix Electronics and suitable for avionics data loggers, tactical radio baseband subsystems, missile guidance modules, and ruggedized industrial PLCs requiring stable component supply across extended military temperature ranges and long-term obsolescence management.
Supply support for 71256L45DB 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 71256L45DB belongs to Renesas' legacy high-reliability SRAM product line, engineered specifically for defense and aerospace applications demanding MIL-STD-883 qualification, extended temperature operation, and battery-backed data integrity.
FAQ
What is the minimum supply voltage required for data retention in the 71256L45DB?
The 71256L45DB guarantees data retention down to 2.0V across its full military temperature range (–55°C to +125°C). This allows direct connection to unregulated 2V lithium backup cells without voltage regulation circuitry, simplifying design and improving system-level reliability during main power loss.
Does the 71256L45DB support both WE-controlled and CS-controlled write operations?
Yes, the 71256L45DB supports both WE-controlled and CS-controlled write cycles as defined in its timing waveforms. The device accepts writes when CS and WE are simultaneously low, with precise setup/hold requirements (tAS = 0ns, tDH = 0ns) validated across all military temperatures.
What is the difference between ISB and ISB1 standby current specifications for the 71256L45DB?
ISB (20mA max) activates when CS exceeds VIH (≥2.2V), providing TTL-level standby; ISB1 (1.5mA max) activates when CS exceeds VHC (VCC – 0.2V), delivering deeper CMOS-level power savings. Designers select based on system logic family and wake-up latency tolerance.
Is the 71256L45DB pin-compatible with the 71256S45DB?
Yes, the 71256L45DB and 71256S45DB share identical pinout, package (CD28 ceramic DIP), and AC/DC electrical specifications except for standby current and data retention voltage. They are functionally interchangeable in hardware layouts, though firmware may require adjustment for power management behavior.
What packaging and screening options are available for the 71256L45DB?
The 71256L45DB is supplied in a 28-pin 600-mil ceramic DIP (CD28) and is screened to MIL-STD-883 Class B, including tests for thermal cycling, mechanical shock, vibration, and hermeticity. It is not offered in plastic packages or commercial temperature grades.
71256L45DB 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:
- 45ns
- Access Time:
- 45 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
71256L45DB FAQ
1.How can I place an order for 71256L45DB through Aetrix?
Please submit a Request for Quotation (RFQ) for 71256L45DB 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 71256L45DB reliable?
The price and inventory of 71256L45DB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71256L45DB is usually 5 days.
3.What payment methods are accepted for 71256L45DB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71256L45DB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71256L45DB?
71256L45DB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71256L45DB 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 71256L45DB?
For technical support, including 71256L45DB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71256L45DB requirements.
6.How does Aetrix verify that 71256L45DB is sourced from the original manufacturer or authorized distributors?
All 71256L45DB 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 71256L45DB meets industry standards.
7.What is the process for return or replacement of 71256L45DB?
All 71256L45DB units undergo pre-shipment inspection (PSI). If there is an issue with 71256L45DB, 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 71256L45DB part is unused and in its original packaging.
Return procedure for 71256L45DB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71256L45DB Tags
-
M24C02-WMN6TP
STMicroelectronics
-
AT24C02C-XHM-T
Microchip Technology
-
AT21CS01-STUM10-T
Microchip Technology
-
AT24C02C-SSHM-T
Microchip Technology
-
24LC01BT-I/OT
Microchip Technology
-
M24C02-FMC6TG
STMicroelectronics
-
AT24CS02-SSHM-T
Microchip Technology
-
93LC46BT-I/OT
Microchip Technology
-
AT24C04C-SSHM-T
Microchip Technology
-
24LC01BT-I/SN
Microchip Technology
-
24AA02UIDT-I/OT
Microchip Technology
-
AT24C08C-STUM-T
Microchip Technology
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
