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Renesas IDT71256SA20YI
- Part No.:
- IDT71256SA20YI
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-BSOJ (0.300", 7.62mm Width)
- Datasheet:
-
IDT71256SA20YI.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28SOJ
- Quantity:
- Payment:
- Shipping:
Inventory:1,817
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Product details
Overview
IDT71256SA20YI from Renesas Electronics is a 32K × 8-bit (262,144-bit) high-speed CMOS static RAM operating at 5V with 20 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 (ISB1 = 15 mA). It serves as main memory or buffer in legacy industrial controllers requiring deterministic, non-refreshed data retention.
For engineers reviewing the IDT71256SA20YI datasheet, IDT71256SA20YI pinout, IDT71256SA20YI application, or IDT71256SA20YI equivalent, key selection criteria include guaranteed 20 ns read/write cycle timing under industrial temperature, CS/OE dual-control architecture for flexible bus interfacing, SOJ package compatibility with legacy PCB footprints, and CMOS-level standby current optimization for power-constrained embedded systems.
Technical Context
The IDT71256SA20YI implements fully static asynchronous logic with no clocks or refresh required, supporting direct connection to microprocessor address/data buses via TTL-compatible inputs and outputs. Its control architecture uses independent CS and OE pins to decouple memory selection from output gating-enabling simultaneous chip enable and output disable for bus contention management.
It supports two distinct standby modes: ISB (TTL-level CS deassertion, 40 mA max) and ISB1 (CMOS-level CS deassertion, 15 mA max), both validated across –40°C to +85°C. The device uses high-reliability CMOS fabrication and meets green (RoHS-compliant) material requirements per ordering code "YI".
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144-bit total); matches standard 8-bit data bus width without byte masking logic |
| Access Time (tAA) | 20 ns max at VCC = 4.5–5.5 V and TA = –40°C to +85°C; ensures timing closure with 50 MHz CPU buses |
| Read Cycle Time (tRC) | 20 ns max; defines minimum interval between successive read operations on same chip |
| Standby Current (ISB1) | 15 mA max at VCC = 5.5 V and f = 0; enables ultra-low-power sleep mode when CS > VHC |
| Supply Voltage | 4.5 V to 5.5 V; compatible with legacy 5V TTL/CMOS system rails without regulation overhead |
| I/O Compatibility | TTL input thresholds (VIH ≥ 2.2 V, VIL ≤ 0.8 V) and output drive (VOH ≥ 2.4 V @ –4 mA, VOL ≤ 0.4 V @ 8 mA) |
| Operating Temperature | –40°C to +85°C; qualified for industrial automation, motor drives, and outdoor instrumentation |
Pinout & Package
Package: 28-pin 300-mil plastic SOJ (PJG28), JEDEC MS-012AC compliant, lead-free and RoHS-compliant per "YI" suffix.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus (32K = 2¹⁵); latched internally on CS transition; no external latch required |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit TTL-compatible data path; direction controlled by WE and CS; high-impedance when deselected or OE high |
| CS | Chip Select Input | Active-low enable; controls power state (ISB/ISB1) and memory array activation; primary chip-enable signal |
| OE | Output Enable Input | Active-low; gates output drivers only; allows CS assertion while holding outputs in high-Z to avoid bus contention |
| WE | Write Enable Input | Active-low; initiates write cycle when CS = L; determines timing reference for tDW, tDH, and tWP parameters |
| VCC | Power Supply | +5V supply pin; must be decoupled locally; supports full 4.5–5.5 V range across industrial temperature |
| GND | Ground Reference | Signal and power ground; requires low-inductance connection to minimize noise coupling into memory array |
Key Features
| Feature | Design Value |
|---|---|
| Dual Control Architecture (CS + OE) | Enables independent chip selection and output gating-critical for shared-bus systems where multiple devices coexist |
| CMOS-Level Standby (ISB1) | Reduces quiescent current to 15 mA when CS driven above VHC (≈4.8 V), enabling deeper power savings than TTL-level ISB |
| 20 ns Industrial-Grade Timing | Guaranteed tAA and tRC ≤ 20 ns over full –40°C to +85°C range-eliminates derating for thermal margin in harsh environments |
| TTL-Compatible I/O | Direct interface to legacy 5V microcontrollers and FPGAs without level-shifting; VOH/VOL meet 8 mA/–4 mA drive specs |
| Green (RoHS) Compliance | Lead-free SOJ package with halogen-free molding compound; satisfies environmental compliance for industrial OEM shipments |
Applications
| Industrial PLC Memory Buffer | Legacy CNC Controller Data Store |
|---|---|
|
Use Scenario: Storing real-time I/O mapping tables and motion trajectory buffers in programmable logic controllers deployed in factory-floor cabinets. IC Role / Device Role / Timing Role: Primary 32K × 8 non-refreshed RAM providing deterministic read/write latency for cyclic scan execution. Use Value: 20 ns access time ensures sub-1 µs memory access within 1 ms PLC scan cycles; industrial temp rating prevents thermal shutdown during cabinet overheating. |
Use Scenario: Holding G-code segment buffers and axis position history in retrofit CNC motion controllers using 80C188 or similar 5V CPUs. IC Role / Device Role / Timing Role: Asynchronous SRAM interfaced directly to CPU address/data bus with CS/OE handshaking for burst transfers. Use Value: SOJ package matches legacy board layouts; TTL compatibility avoids redesign of bus termination; ISB1 mode cuts standby power during spindle idle periods. |
| Avionics Data Logger Cache | Railway Signaling Event Recorder |
|
Use Scenario: Capturing flight sensor snapshots (pressure, temperature, attitude) at 1 kHz in certified avionics black-box recorders. IC Role / Device Role / Timing Role: High-reliability static RAM used as write-through cache before EEPROM archiving; no refresh failures possible. Use Value: Fully static operation eliminates timing jitter from refresh cycles; –40°C to +85°C rating covers aircraft cabin and avionics bay extremes. |
Use Scenario: Logging train position, speed, and signal aspect transitions in EN 5012x-compliant railway interlocking systems. IC Role / Device Role / Timing Role: Deterministic memory for safety-critical event buffering where predictability outweighs density. Use Value: Guaranteed 20 ns timing enables worst-case analysis per IEC 61508; green packaging meets EU rail environmental directives. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-speed static RAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY62256LL-20ZSXI | Same 32K × 8 organization, 20 ns access, but uses 28-pin TSOP (ZS) instead of SOJ; ISB1 = 25 mA (vs. 15 mA) | Requires PCB footprint change; higher standby current reduces battery backup runtime in portable loggers | Choose if TSOP layout already exists and lower ISB1 is not critical |
| AS6C4008-20TIN | Pin-compatible 28-pin SOJ, 20 ns, but rated only for commercial temp (0°C to +70°C); ISB1 = 12 mA | Not suitable for uncontrolled-temperature deployments like outdoor signaling cabinets or engine bays | Choose only for cost-sensitive commercial-grade systems with ambient thermal management |
Compared with IDT71256SA20YI, CY62256LL-20ZSXI offers identical speed but higher standby current and different package, while AS6C4008-20TIN provides lower ISB1 but lacks industrial temperature qualification-making IDT71256SA20YI the sole option meeting both 20 ns timing and –40°C to +85°C operation in SOJ.
Availability
IDT71256SA20YI is available at Aetrix Electronics and suitable for industrial PLC memory buffers, legacy CNC controller data stores, avionics data logger caches, and railway signaling event recorders requiring stable component supply across extended lifecycles.
Supply support for IDT71256SA20YI 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 is a global semiconductor leader specializing in microcontrollers, analog, power, and memory solutions for industrial, automotive, and infrastructure markets.
IDT71256SA20YI belongs to Renesas' legacy high-speed CMOS SRAM product line, designed specifically for deterministic, non-refreshed memory applications in industrial control, instrumentation, and safety-critical embedded systems.
FAQ
What is the maximum guaranteed access time for IDT71256SA20YI across its full operating temperature range?
IDT71256SA20YI guarantees a maximum address access time (tAA) of 20 ns over the full industrial temperature range of –40°C to +85°C at VCC = 4.5 V to 5.5 V. This value is production-tested and specified in the AC Electrical Characteristics table for part number 71256SA20, confirming deterministic timing behavior without derating for thermal margin in harsh environments.
Does IDT71256SA20YI require a clock or refresh circuitry to retain data?
No, IDT71256SA20YI uses fully static asynchronous CMOS design and requires no clock signals or periodic refresh cycles to retain stored data. Its internal latching circuitry maintains state indefinitely as long as VCC remains within specification (4.5–5.5 V) and temperature stays within –40°C to +85°C-making it ideal for fail-safe logging and control applications.
What does the "YI" suffix in IDT71256SA20YI indicate?
The "YI" suffix in IDT71256SA20YI denotes two key attributes: "Y" specifies the 28-pin 300-mil plastic SOJ (PJG28) package, and "I" indicates industrial temperature grade (–40°C to +85°C). This suffix also implies RoHS-compliant, green (lead-free) construction per Renesas' ordering conventions documented in the datasheet's Ordering Information section.
How does the dual-control architecture (CS + OE) of IDT71256SA20YI improve system bus management?
IDT71256SA20YI's separate CS and OE pins allow independent control of chip selection and output driver enablement. This permits CS to remain asserted while OE is deasserted-keeping the device powered and ready but placing I/O lines in high-impedance to prevent bus contention during multi-device arbitration, a capability not supported by single-enable SRAMs.
Is IDT71256SA20YI still recommended for new designs according to Renesas documentation?
Yes-IDT71256SA20YI is actively supported and not marked obsolete. The Renesas datasheet revision dated June 29, 2020 explicitly removed the prior "Not recommended for new designs" notice (which was withdrawn in February 2001), and updated industrial temperature availability, green compliance, and ordering information-confirming ongoing manufacturability and technical support for IDT71256SA20YI.
IDT71256SA20YI 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:
- 20ns
- Access Time:
- 20 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
IDT71256SA20YI FAQ
1.How can I place an order for IDT71256SA20YI through Aetrix?
Please submit a Request for Quotation (RFQ) for IDT71256SA20YI 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 IDT71256SA20YI reliable?
The price and inventory of IDT71256SA20YI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IDT71256SA20YI is usually 5 days.
3.What payment methods are accepted for IDT71256SA20YI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IDT71256SA20YI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for IDT71256SA20YI?
IDT71256SA20YI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your IDT71256SA20YI 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 IDT71256SA20YI?
For technical support, including IDT71256SA20YI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IDT71256SA20YI requirements.
6.How does Aetrix verify that IDT71256SA20YI is sourced from the original manufacturer or authorized distributors?
All IDT71256SA20YI 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 IDT71256SA20YI meets industry standards.
7.What is the process for return or replacement of IDT71256SA20YI?
All IDT71256SA20YI units undergo pre-shipment inspection (PSI). If there is an issue with IDT71256SA20YI, 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 IDT71256SA20YI part is unused and in its original packaging.
Return procedure for IDT71256SA20YI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
IDT71256SA20YI 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
Microchip Technology
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M24C02-FMC6TG
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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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