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Renesas IDT71256SA15YI
- Part No.:
- IDT71256SA15YI
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-BSOJ (0.300", 7.62mm Width)
- Datasheet:
-
IDT71256SA15YI.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28SOJ
- Quantity:
- Payment:
- Shipping:
Inventory:3,337
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Product details
Overview
IDT71256SA15YI from Renesas Electronics is a 32K × 8-bit (256 Kbit) high-speed CMOS static RAM operating at 5 V, with 15 ns access time and industrial temperature range (–40°C to +85°C), packaged in 28-pin 300-mil plastic SOJ (PJG28). It features TTL-compatible bidirectional I/O, separate chip select (CS) and output enable (OE), and low-power standby modes (ISB = 40 mA, ISB1 = 15 mA). It is used in legacy industrial control systems requiring deterministic, non-refreshed memory with fast random access.
For engineers reviewing the IDT71256SA15YI datasheet, IDT71256SA15YI pinout, IDT71256SA15YI application, or IDT71256SA15YI equivalent, this page delivers verified timing parameters, package-specific DC/AC electrical characteristics, functional truth table behavior, and validated industrial-grade alternatives - all aligned to the Renesas-rebranded 2020 datasheet (Doc #2948).
Technical Context
The IDT71256SA15YI implements fully static asynchronous logic with no clocks or refresh required. Its address decoder supports 15 address inputs (A0–A14), enabling full 32K-word addressing, and its control architecture separates chip selection (CS) from output gating (OE), allowing flexible bus sharing and partial-memory disable.
It uses dual standby current modes: TTL-level standby (ISB = 40 mA max at VCC = 5.5 V) when CS > VIH, and deeper CMOS-level standby (ISB1 = 15 mA max) when CS > VHC and all inputs are valid high/low - critical for power-sensitive industrial embedded designs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144 bits), fixed parallel interface with no internal banking or multiplexing |
| Access Time (tAA) | 15 ns max - guarantees data valid within 15 ns of stable address + CS assertion, enabling ≤66.7 MHz burst read capability |
| Supply Voltage | 4.5 V to 5.5 V - compatible with standard 5 V TTL logic rails without regulation overhead |
| I/O Compatibility | TTL-compatible inputs and outputs - interfaces directly with 74LS/ALS logic and microcontrollers without level shifters |
| Operating Temperature | –40°C to +85°C - qualified for industrial environments including factory automation and motor drive controllers |
| Standby Current (ISB1) | 15 mA max at VCC = 5.5 V - enables low-power sleep mode when CS held above VHC and no bus activity occurs |
| Output Enable Delay (tOE) | 7 ns max - allows rapid read-enable toggling during multi-device memory arbitration |
Pinout & Package
Package: 28-pin 300-mil plastic SOJ (PJG28), surface-mount, gull-wing leads, JEDEC MS-013 compliant.
| 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 | Bidirectional Data Bus | 8-bit TTL-compatible data path; direction controlled by WE and OE states per truth table |
| CS | Chip Select | Active-low enable; device enters standby (high-Z outputs) when high; controls ISB/ISB1 current modes |
| OE | Output Enable | Active-low; gates output drivers independently of CS - enables memory sharing on common data bus |
| WE | Write Enable | Active-low; initiates write cycle when CS and WE both low; determines tWP (10 ns min) and tDW (7 ns min) |
| VCC | Power Supply | +5 V supply pin; must be decoupled locally due to dynamic ICC = 150 mA max during active read/write |
| GND | Ground | Reference return for all signals and power; requires low-inductance connection to minimize noise coupling |
Key Features
| Feature | Design Value |
|---|---|
| Asynchronous Static Operation | No clock, no refresh, no wait states - simplifies timing-critical control firmware and eliminates DRAM controller overhead |
| Dual Standby Current Modes | ISB = 40 mA (TTL-level CS) and ISB1 = 15 mA (CMOS-level CS) - enables hierarchical power management in multi-SRAM systems |
| Separate OE and CS Control | Allows memory-mapped peripherals to share data bus while IDT71256SA15YI remains selected but output-disabled |
| TTL-Compatible I/O | VIH = 2.2 V min, VOL = 0.4 V max at 8 mA - ensures robust noise margin and direct interfacing with legacy 5 V microcontrollers |
| Industrial Temperature Qualification | Tested and guaranteed across –40°C to +85°C - supports deployment in uncontrolled enclosures and extended thermal cycles |
Applications
| Industrial PLC Data Buffers | Legacy CNC Motion Controller Memory |
|---|---|
|
Use Scenario: Storing real-time I/O status, motion trajectory points, and ladder logic variables in programmable logic controllers with no external memory controller. IC Role / Device Role / Timing Role: Primary volatile data store accessed via parallel bus from 80C188 or similar industrial MPU; provides deterministic 15 ns read latency. Use Value: Eliminates need for external wait-state generation or SRAM controller ASIC, reducing BOM count and PCB area in space-constrained DIN-rail modules. |
Use Scenario: Holding interpolated position tables and servo loop coefficients in retrofit CNC panels where original design used 5 V TTL-based memory subsystems. IC Role / Device Role / Timing Role: Drop-in replacement for obsolete 28-pin SRAMs in motion control boards; maintains identical pinout and timing margins under worst-case temperature. Use Value: Enables life-extension of fielded CNC equipment without redesigning memory interface logic or requalifying entire board assembly. |
| Avionics Test Equipment Buffers | Ruggedized Data Acquisition Modules |
|
Use Scenario: Capturing transient sensor waveforms during ground-test of aircraft subsystems, where memory must retain data integrity during thermal shock and vibration. IC Role / Device Role / Timing Role: High-reliability buffer memory interfaced to FPGA-based capture engines; operates continuously at +85°C ambient with minimal derating. Use Value: Meets DO-254 traceability requirements for Class E hardware due to Renesas' long-lifecycle support and documented industrial qualification. |
Use Scenario: Logging analog-to-digital conversion results in oil-field downhole tools exposed to wide temperature swings and EMI-rich environments. IC Role / Device Role / Timing Role: Non-refreshed storage element synchronized to microcontroller's parallel bus; tolerates voltage droop during battery switchover events. Use Value: Guarantees data retention during brown-out conditions thanks to low ISB1 current and wide VCC range (4.5–5.5 V). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar static RAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY62128EV30LL-45ZSXI | 32K × 8-bit, 45 ns access, 3.3 V core (with 5 V tolerant I/O), SOJ-28 package | Requires level translation or mixed-voltage design; slower access invalidates timing-critical 15 ns use cases | Select only if system already uses 3.3 V logic and can absorb 30 ns longer read latency |
| AS6C4008-15ZIN | 512K × 8-bit, 15 ns access, 5 V operation, SOJ-28, but larger density and higher ICC (200 mA) | Higher capacity may cause address decoding changes; increased dynamic current demands stronger decoupling | Choose only when memory expansion beyond 256 Kbit is needed and PCB layout accommodates higher power dissipation |
Compared with IDT71256SA15YI, CY62128EV30LL-45ZSXI trades speed for voltage compatibility, while AS6C4008-15ZIN trades pin-compatibility for density - neither offers identical 15 ns / 5 V / industrial-temp performance in the same footprint.
Availability
IDT71256SA15YI is available at Aetrix Electronics and suitable for industrial PLC data buffering, legacy CNC motion controller upgrades, avionics test equipment, and ruggedized data acquisition modules requiring stable component supply across extended product lifecycles.
Supply support for IDT71256SA15YI 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 delivering microcontrollers, analog, power, and memory solutions for automotive, industrial, and infrastructure markets.
IDT71256SA15YI belongs to Renesas' legacy high-speed parallel SRAM product line, designed specifically for industrial and aerospace applications demanding deterministic timing, wide temperature operation, and long-term supply stability.
FAQ
What is the maximum operating frequency supported by IDT71256SA15YI?
IDT71256SA15YI does not operate on a clock signal - it is an asynchronous static RAM. Its maximum effective read rate is determined by tRC (read cycle time) of 15 ns, supporting up to 66.7 million read cycles per second in continuous operation. This assumes full address and control setup/hold compliance per the AC timing table in the Renesas datasheet (2948, Rev. Jun.29.20).
Does IDT71256SA15YI require external refresh circuitry?
No, IDT71256SA15YI is a fully static RAM and requires no refresh cycles or external refresh circuitry. Its CMOS memory array retains data indefinitely as long as VCC is applied and temperature remains within –40°C to +85°C. This eliminates complexity in microcontroller-based systems that lack dedicated DRAM controllers.
Can IDT71256SA15YI be used with modern 3.3 V microcontrollers?
IDT71256SA15YI operates strictly at 5 V (4.5–5.5 V) and has TTL-compatible I/O thresholds - it is not 3.3 V tolerant. Direct connection to 3.3 V MCUs risks input overvoltage and output level mismatch. A level-shifting solution (e.g., TXB0108 or discrete resistor dividers) is required for safe interoperability with IDT71256SA15YI.
What is the difference between ISB and ISB1 standby current in IDT71256SA15YI?
IDT71256SA15YI defines two standby modes: ISB (40 mA max) activates when CS > VIH (≥2.2 V), and ISB1 (15 mA max) activates when CS > VHC (VCC – 0.2 V) and all inputs are valid high/low. ISB1 achieves deeper power savings but requires stricter input voltage compliance - critical for battery-backed industrial systems using IDT71256SA15YI.
Is IDT71256SA15YI RoHS-compliant and halogen-free?
Yes, IDT71256SA15YI is a "Green" part per Renesas ordering information (2948, pg. 7), meaning it complies with RoHS Directive 2011/65/EU and is halogen-free. The "G" suffix in package codes (e.g., YGI) denotes green material set, and the device carries Renesas' Restricted Hazardous Substance declaration per the 2020 datasheet revision.
IDT71256SA15YI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 28-BSOJ (0.300", 7.62mm Width)
- 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:
- 15ns
- Access Time:
- 15 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-SOJ
IDT71256SA15YI FAQ
1.How can I place an order for IDT71256SA15YI through Aetrix?
Please submit a Request for Quotation (RFQ) for IDT71256SA15YI 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 IDT71256SA15YI reliable?
The price and inventory of IDT71256SA15YI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IDT71256SA15YI is usually 5 days.
3.What payment methods are accepted for IDT71256SA15YI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IDT71256SA15YI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for IDT71256SA15YI?
IDT71256SA15YI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your IDT71256SA15YI 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 IDT71256SA15YI?
For technical support, including IDT71256SA15YI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IDT71256SA15YI requirements.
6.How does Aetrix verify that IDT71256SA15YI is sourced from the original manufacturer or authorized distributors?
All IDT71256SA15YI 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 IDT71256SA15YI meets industry standards.
7.What is the process for return or replacement of IDT71256SA15YI?
All IDT71256SA15YI units undergo pre-shipment inspection (PSI). If there is an issue with IDT71256SA15YI, 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 IDT71256SA15YI part is unused and in its original packaging.
Return procedure for IDT71256SA15YI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
IDT71256SA15YI Tags
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