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Renesas IDT71256L35Y8
- Part No.:
- IDT71256L35Y8
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-BSOJ (0.300", 7.62mm Width)
- Datasheet:
-
IDT71256L35Y8.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28SOJ
- Quantity:
- Payment:
- Shipping:
Inventory:1,704
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Product details
Overview
IDT71256L35Y8 from Integrated Device Technology is a 256K (32K × 8-bit) low-power CMOS static RAM with 35ns maximum access time, TTL-compatible I/O, and 2V battery backup data retention. It operates across industrial temperature range (–40°C to +85°C), consumes ≤3µA in full standby mode, and is packaged in 28-pin 300-mil SOJ for high-density board layouts. Used in legacy industrial controllers requiring non-volatile SRAM with deterministic timing.
For engineers reviewing the IDT71256L35Y8 datasheet, IDT71256L35Y8 pinout, IDT71256L35Y8 application, or IDT71256L35Y8 equivalent, key selection criteria include standby current under CMOS-level chip select, battery-retention voltage margin, AC timing compliance at –40°C/+85°C, and SOJ-28 mechanical compatibility with legacy PCB footprints.
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 data bus (I/O0–I/O7). Control logic uses three independent enables-CS (chip select), WE (write enable), and OE (output enable)-to manage read/write cycles and high-impedance tri-state output behavior.
Its low-power architecture features dual standby modes: TTL-level CS > VIH triggers ISB (≤3mA), while CMOS-level CS > VHC activates ISB1 (≤1.5µA typical). Battery backup operation is supported only in L-version devices, retaining data at VCC = 2.0V with ICCDR ≤120µA (typ.) over industrial temperature range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144 bits), fixed parallel interface with no internal refresh required |
| Access Time (tAA) | 35ns max - guarantees valid data at I/O pins within 35ns after stable address and CS assertion |
| Supply Voltage | 5.0V ±10% - compatible with standard TTL/CMOS logic rails; no external regulation needed |
| Standby Current (ISB1) | ≤1.5µA typical - enables multi-year battery-backed retention in power-critical systems |
| Data Retention Voltage | 2.0V min - supports operation from single Li-MnO₂ or two alkaline cells without boost circuitry |
| Operating Temperature | –40°C to +85°C - qualified for industrial control, test equipment, and telecom line cards |
| Input/Output Compatibility | TTL input thresholds (VIH ≥2.2V, VIL ≤0.8V); outputs drive ±10mA - direct drop-in for 74LS/ALS logic |
Pinout & Package
Package: 28-pin SOJ (Small Outline J-Lead), 300-mil width, JEDEC MS-012AC compliant, lead-free capable per IDT specification.
| 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 data path; high-impedance when CS high or during write cycles with OE high |
| CS | Chip Select | Active-low enable; asserts memory array and I/O drivers; CMOS-level threshold enables ultra-low ISB1 |
| WE | Write Enable | Active-low control for write operations; combined with CS LOW to initiate data latching into memory cell |
| OE | Output Enable | Active-low control for output drivers; allows read data to appear on I/O lines without affecting write state |
| VCC | Power Supply | +5V supply pin; decoupling capacitor required within 10mm for stable 35ns timing compliance |
| GND | Ground Reference | Signal and power ground return; must be connected to low-impedance plane to minimize tOH/tOLZ jitter |
Key Features
| Feature | Design Value |
|---|---|
| Low-power standby (ISB1) | 1.5µA typical at VCC = 5.5V - reduces system sleep-mode power by >99% vs. standard SRAMs |
| Battery backup retention | 2.0V minimum VCC - eliminates need for external voltage supervisors or charge pumps in backup circuits |
| TTL-compatible I/O | VIH = 2.2V min, VOL = 0.4V max at 8mA - interoperates directly with legacy 74-series logic without level shifters |
| Military-grade reliability | MIL-STD-883 Class B screening available - ensures long-term operation in vibration-prone or thermally cycled environments |
| SOJ-28 footprint | 300-mil body width, J-lead pitch 0.050″ - supports automated reflow assembly and provides superior thermal dissipation vs. DIP |
Applications
| Industrial PLC Data Buffer | Avionics Display Memory |
|---|---|
|
Use Scenario: Storing real-time I/O status and configuration registers in programmable logic controllers deployed in factory automation cabinets. IC Role / Device Role / Timing Role: Non-volatile scratchpad memory holding last-known state during mains failure; retains data via onboard coin-cell backup. Use Value: Enables deterministic recovery within 10ms of power restoration without firmware reload or checksum validation delays. |
Use Scenario: Frame buffer storage for monochrome cockpit display units where EMI resilience and thermal stability are critical. IC Role / Device Role / Timing Role: High-reliability SRAM serving as pixel map storage; accessed synchronously with raster scan controller at 60Hz. Use Value: 35ns tAA ensures pixel data availability before horizontal blanking interval ends, eliminating screen tearing. |
| Telecom Line Card Cache | Medical Diagnostic Equipment Log Buffer |
|
Use Scenario: Temporary packet header storage in T1/E1 framer modules operating in NEBS-compliant central office environments. IC Role / Device Role / Timing Role: Low-latency buffer between serial framer and host processor; accessed via burst reads during idle frame slots. Use Value: ≤1.5µA ISB1 extends battery life beyond 10 years in maintenance-free remote node deployments. |
Use Scenario: Capturing sensor calibration coefficients and fault logs in portable ultrasound machines requiring FDA 510(k) traceability. IC Role / Device Role / Timing Role: Write-once/read-many memory storing immutable diagnostic metadata prior to USB export. Use Value: 2V data retention allows use of primary lithium CR2032 cells without voltage regulation, reducing BOM count by one IC. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar static RAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY62256LL-45ZSXIT | 45ns access time; 32-pin TSOP-I package; ISB1 = 2µA typical; same 32K×8 organization | Requires PCB redesign due to 32-pin TSOP footprint; lacks MIL-STD-883 qualification | Select when higher-volume automated assembly justifies footprint change and military screening is unnecessary |
| AS6C4008-35TIN | 35ns access; 28-pin SOJ; ISB1 = 5µA typical; 5V-only supply; no battery retention spec | Not rated for 2V data retention; industrial temp only; lower reliability screening than IDT71256L35Y8 | Choose for cost-sensitive industrial designs where battery backup is handled externally |
Compared with CY62256LL-45ZSXIT and AS6C4008-35TIN, IDT71256L35Y8 uniquely delivers 35ns performance in SOJ-28 with guaranteed 2V battery retention and MIL-STD-883 Class B screening-making it irreplaceable in legacy aerospace and defense upgrades requiring zero PCB changes.
Availability
IDT71256L35Y8 is available at Aetrix Electronics and suitable for industrial PLC data buffers, avionics display memory, and telecom line card cache requiring stable component supply across extended product lifecycles.
Supply support for IDT71256L35Y8 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
Integrated Device Technology (IDT), founded in 1980, pioneered high-speed SRAM and clock solutions for computing and communications infrastructure before its acquisition by Renesas in 2019.
IDT71256L35Y8 belongs to IDT's legacy 71xxx SRAM family, engineered for deterministic timing, ultra-low standby power, and robust operation in harsh industrial and military environments.
FAQ
What is the minimum VCC required for data retention in IDT71256L35Y8?
IDT71256L35Y8 guarantees data retention down to 2.0V across its full industrial temperature range (–40°C to +85°C), as specified in Table 11 of the datasheet. This enables direct connection to a single 2.0V lithium battery without voltage regulation. The device draws ≤120µA (typ.) at 2.0V during retention mode, supporting multi-year backup operation. IDT71256L35Y8 does not retain data below 2.0V, and operation outside this voltage violates the retention specification.
Does IDT71256L35Y8 support true static operation without refresh cycles?
Yes, IDT71256L35Y8 is a fully static CMOS SRAM with no internal refresh requirement. Its 32K × 8-bit memory array retains data indefinitely as long as VCC remains within specification and CS is held HIGH in standby or driven LOW during active access. The absence of refresh simplifies system design-no external refresh controller or timing overhead is needed. IDT71256L35Y8 maintains data integrity even with zero clock or address activity for decades under proper bias conditions.
What is the meaning of "Y8" in the part number IDT71256L35Y8?
The "Y8" suffix in IDT71256L35Y8 denotes the 28-pin 300-mil SOJ package variant with industrial temperature range (–40°C to +85°C) and low-power (L) functionality. Per IDT's ordering guide (Figure 2946 drw 13), "Y" specifies SOJ-28 packaging and "8" indicates industrial grade. This distinguishes it from ceramic DIP (D28-3), plastic DIP (P28-1), or LCC (L32-1) variants. IDT71256L35Y8 is not pin-compatible with any 32-pin version.
Can IDT71256L35Y8 be used in place of IDT71256S35Y8?
IDT71256L35Y8 and IDT71256S35Y8 share identical speed (35ns), package (SOJ-28), and temperature rating, but differ critically in power architecture: the "L" version delivers ≤1.5µA full-standby current and 2V battery retention, while the "S" version draws ≤20mA ISB and has no retention spec. Substitution is electrically safe but invalidates battery backup functionality. IDT71256L35Y8 must be used where low-power retention is required; IDT71256S35Y8 suits cost-sensitive applications without backup needs.
Is IDT71256L35Y8 compliant with RoHS or lead-free assembly requirements?
IDT71256L35Y8 was manufactured prior to mandatory RoHS enforcement and uses leaded solder in its SOJ leads. While IDT documented lead-free conversion paths for later SRAM families, no official lead-free variant of IDT71256L35Y8 was released. Aetrix Electronics supplies only original IDT-marked IDT71256L35Y8 units meeting the 2001 datasheet specifications, which predate RoHS. For new designs requiring RoHS compliance, alternative modern SRAMs must be evaluated.
IDT71256L35Y8 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 28-BSOJ (0.300", 7.62mm Width)
- Packaging:
- Tape & Reel (TR)
- 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:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-SOJ
IDT71256L35Y8 FAQ
1.How can I place an order for IDT71256L35Y8 through Aetrix?
Please submit a Request for Quotation (RFQ) for IDT71256L35Y8 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 IDT71256L35Y8 reliable?
The price and inventory of IDT71256L35Y8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IDT71256L35Y8 is usually 5 days.
3.What payment methods are accepted for IDT71256L35Y8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IDT71256L35Y8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for IDT71256L35Y8?
IDT71256L35Y8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your IDT71256L35Y8 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 IDT71256L35Y8?
For technical support, including IDT71256L35Y8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IDT71256L35Y8 requirements.
6.How does Aetrix verify that IDT71256L35Y8 is sourced from the original manufacturer or authorized distributors?
All IDT71256L35Y8 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 IDT71256L35Y8 meets industry standards.
7.What is the process for return or replacement of IDT71256L35Y8?
All IDT71256L35Y8 units undergo pre-shipment inspection (PSI). If there is an issue with IDT71256L35Y8, 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 IDT71256L35Y8 part is unused and in its original packaging.
Return procedure for IDT71256L35Y8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
IDT71256L35Y8 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
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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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