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Renesas IDT71256SA12YI8
- Part No.:
- IDT71256SA12YI8
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-BSOJ (0.300", 7.62mm Width)
- Datasheet:
-
IDT71256SA12YI8.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28SOJ
- Quantity:
- Payment:
- Shipping:
Inventory:4,061
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Product details
Overview
IDT71256SA12YI8 from Renesas Electronics is a 32K × 8-bit (262,144-bit) high-speed CMOS static RAM with 12 ns access time, industrial temperature range (–40°C to +85°C), single 5V supply operation, TTL-compatible I/O, and bidirectional data bus. It serves as main or buffer memory in real-time control systems requiring deterministic, clockless read/write cycles.
For engineers reviewing the IDT71256SA12YI8 datasheet, IDT71256SA12YI8 pinout, IDT71256SA12YI8 application, or IDT71256SA12YI8 equivalent, this part delivers verified 12 ns address access, 12 ns read cycle time, low-power standby modes (ISB1 = 15 mA), and SOJ-28 packaging for legacy industrial board replacements where asynchronous SRAM timing and pin-level compatibility are critical.
Technical Context
The IDT71256SA12YI8 implements fully static asynchronous circuitry-no clocks, no refresh required-and uses dual-control enable logic with independent Chip Select (CS) and Output Enable (OE) inputs to manage output gating and device selection. Its architecture supports simultaneous address decoding and data path activation without internal latching delays.
All 15 address lines (A0–A14), 8 bidirectional I/O pins (I/O0–I/O7), and three control inputs (CS, WE, OE) operate at TTL voltage levels (VIH = 2.2 V min, VIL = 0.8 V max) with 5 V ±10% supply. Standby current drops to 15 mA under CMOS-level deselection (CS > VHC), enabling low-power hold states in battery-backed systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144-bit total); enables byte-wide data transfers without external multiplexing |
| Access Time (tAA) | 12 ns max; guarantees data valid within 12 ns of stable address and CS assertion-critical for tight-loop microcontroller interfaces |
| Read Cycle Time (tRC) | 12 ns min; allows consecutive reads at up to 83.3 MHz sustained rate in burst-access configurations |
| Supply Voltage | 4.5 V to 5.5 V; compatible with standard 5 V TTL/CMOS logic rails without regulation overhead |
| Operating Temperature | –40°C to +85°C; qualified for industrial environments including factory automation and transportation control units |
| Standby Current (ISB1) | 15 mA max at VCC = 5.5 V; achieved only when CS driven above VHC (≈4.8 V), enabling ultra-low-power sleep mode |
| I/O Compatibility | TTL input thresholds and output drive (VOH ≥ 2.4 V @ –4 mA, VOL ≤ 0.4 V @ 8 mA); interoperable with 74LS, 74F, and early microprocessor buses |
Pinout & Package
Package: 28-pin 300-mil Plastic SOJ (PJG28), JEDEC MS-013 compliant, lead pitch 0.05 inch, body width 0.3 inch. Pin 1 index marked by notch or dot; mounting compatible with wave or reflow soldering per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit unidirectional address bus; selects one of 32,768 memory locations; no internal latching-address must be stable before CS low |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit TTL-compatible data path; direction controlled by WE and CS; high-impedance when CS high or OE high during read |
| CS | Chip Select Input | Active-low device enable; controls power state (ISB vs ISB1) and output driver activation; primary device selection signal |
| WE | Write Enable Input | Active-low write strobe; initiates write cycle when CS low; determines timing window for data setup/hold relative to address |
| OE | Output Enable Input | Active-low output gate; enables data drivers independently of CS; allows output disable while chip remains selected |
| VCC | Power Supply | +5 V supply pin; decoupling capacitor (0.1 µF ceramic) required within 0.5 inch for noise immunity in high-speed operation |
| GND | Ground Reference | Signal and power ground return; must be connected to low-impedance plane to maintain VIH/VIL margins under switching noise |
Key Features
| Feature | Design Value |
|---|---|
| 12 ns guaranteed access time | Meets real-time interrupt response deadlines in PLCs and motion controllers where memory latency directly impacts loop jitter |
| Dual enable architecture (CS + OE) | Enables partial bus sharing: multiple devices can share I/O lines while using separate OE signals for selective read arbitration |
| CMOS-level standby (ISB1 = 15 mA) | Reduces system standby power by >65% versus TTL-level standby (ISB = 50 mA), extending battery life in portable test equipment |
| TTL-compatible I/O with 5 V supply | Eliminates level-shifting components when interfacing with legacy 80Cxx, Z80, or 68000-based controllers and peripheral ASICs |
| Industrial temperature qualification | Validated operation across full –40°C to +85°C range with no derating-required for rail signaling, energy metering, and outdoor kiosks |
Applications
| Industrial PLC Memory Buffer | Legacy Microprocessor System Cache |
|---|---|
|
Use Scenario: Storing I/O scan data and intermediate logic results in programmable logic controllers operating in ambient temperatures up to 70°C. IC Role / Device Role / Timing Role: Asynchronous SRAM buffer between CPU and field I/O modules; provides zero-wait-state access for ladder logic execution. Use Value: 12 ns tAA ensures sub-microsecond data availability per scan cycle, reducing overall scan time by up to 18% versus 15 ns alternatives. |
Use Scenario: Serving as instruction/data cache in 8-bit and 16-bit embedded systems based on Z80, 8085, or 68000 architectures. IC Role / Device Role / Timing Role: Byte-wide memory mapped at fixed address space; accessed via standard bus cycles without wait-state insertion. Use Value: TTL-compatible I/O and 5 V operation eliminate interface logic, reducing BOM count and PCB area in retro-computing and instrumentation designs. |
| Automotive Diagnostic Tool RAM | Medical Device Data Logger |
|
Use Scenario: Temporary storage of OBD-II protocol responses and sensor calibration tables in handheld diagnostic scanners deployed in vehicle service bays. IC Role / Device Role / Timing Role: Non-refresh volatile memory holding transient CAN message payloads and lookup tables during active session. Use Value: Industrial temperature rating ensures reliable operation inside vehicles parked under direct sun exposure where cabin temps exceed 80°C. |
Use Scenario: Capturing high-resolution analog waveform samples from ECG or EEG front-ends in portable patient monitors with battery backup. IC Role / Device Role / Timing Role: High-speed acquisition buffer accepting burst writes from ADC controllers; holds data until host processor initiates DMA transfer. Use Value: 12 ns tWC and tDW specifications guarantee accurate capture of 100+ kSPS sampled data without loss during power-fail transitions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar static RAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY62256LL-12ZXC | Same 32K × 8 organization and 12 ns speed, but uses 28-pin TSOP (SOIC-type) package; ISB1 = 25 mA (vs 15 mA) | Preferred for new PCB layouts with surface-mount constraints; less suitable for through-hole SOJ socket replacement | Select when board space is limited and reflow assembly is used; verify trace impedance for 12 ns edge rates on TSOP layout |
| AS6C4008-12PIN | 12 ns access, industrial temp, but requires 2.7–3.6 V supply; not 5 V compatible | Used in modern low-voltage portable medical devices; incompatible with legacy 5 V bus systems | Choose only if entire system operates at 3.3 V; not a drop-in replacement for IDT71256SA12YI8 due to supply voltage mismatch |
Compared with CY62256LL-12ZXC and AS6C4008-12PIN, the IDT71256SA12YI8 uniquely combines 5 V TTL compatibility, SOJ-28 through-hole mountability, and 15 mA CMOS standby current-making it the sole viable option for maintaining legacy industrial controller hardware while meeting updated power and thermal requirements.
Availability
IDT71256SA12YI8 is available at Aetrix Electronics and suitable for industrial PLCs, automotive diagnostic tools, medical data loggers, and legacy microprocessor system upgrades requiring stable component supply across extended product lifecycles.
Supply support for IDT71256SA12YI8 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.
The IDT71256SA12YI8 belongs to Renesas' legacy high-speed CMOS SRAM product line, originally developed by Integrated Device Technology (IDT) and optimized for deterministic, low-latency memory access in real-time embedded control systems.
FAQ
What is the maximum operating frequency supported by the IDT71256SA12YI8?
The IDT71256SA12YI8 does not use a clock and therefore has no operating frequency specification. Its performance is defined by timing parameters: minimum read cycle time (tRC) is 12 ns, supporting up to 83.3 million read cycles per second in ideal conditions. Actual throughput depends on system bus protocol, address stability, and control signal timing margins-not a clock signal.
Is the IDT71256SA12YI8 RoHS compliant and halogen-free?
Yes, the IDT71256SA12YI8 is a Renesas "Green" part, meaning it complies with RoHS Directive 2011/65/EU and is halogen-free per IEC 61249-2-21. This is confirmed in the Ordering Information section of the Renesas datasheet (Rev. Jun.29.20), where "G" suffix denotes green material content.
Can the IDT71256SA12YI8 be used with a 3.3 V microcontroller interface?
No-the IDT71256SA12YI8 requires a 4.5 V to 5.5 V supply and is specified for TTL-compatible signaling (VIH ≥ 2.2 V, VIL ≤ 0.8 V). Direct connection to 3.3 V logic risks violating input high-voltage minimums and may cause unreliable reads/writes. Level translation (e.g., TXB0108) is mandatory for safe 3.3 V system integration.
Does the IDT71256SA12YI8 require refresh circuitry or external clocks?
No-the IDT71256SA12YI8 is a fully static CMOS SRAM. It retains data indefinitely as long as power is applied and requires no refresh cycles, clocks, or periodic access. This eliminates timing-critical support circuitry and simplifies design for safety-critical or low-power-hold applications.
What is the difference between ISB and ISB1 current ratings for the IDT71256SA12YI8?
ISB (50 mA max) applies when CS is pulled to TTL-high (>2.2 V); ISB1 (15 mA max) applies only when CS is driven to CMOS-high (>VCC – 0.2 V ≈ 4.8 V at 5 V). Achieving ISB1 requires precise control of the CS voltage level-typically via a pull-up to VCC with no series resistor-and is used to minimize standby power in battery-backed systems.
IDT71256SA12YI8 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:
- 12ns
- Access Time:
- 12 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
IDT71256SA12YI8 FAQ
1.How can I place an order for IDT71256SA12YI8 through Aetrix?
Please submit a Request for Quotation (RFQ) for IDT71256SA12YI8 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 IDT71256SA12YI8 reliable?
The price and inventory of IDT71256SA12YI8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IDT71256SA12YI8 is usually 5 days.
3.What payment methods are accepted for IDT71256SA12YI8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IDT71256SA12YI8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for IDT71256SA12YI8?
IDT71256SA12YI8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your IDT71256SA12YI8 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 IDT71256SA12YI8?
For technical support, including IDT71256SA12YI8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IDT71256SA12YI8 requirements.
6.How does Aetrix verify that IDT71256SA12YI8 is sourced from the original manufacturer or authorized distributors?
All IDT71256SA12YI8 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 IDT71256SA12YI8 meets industry standards.
7.What is the process for return or replacement of IDT71256SA12YI8?
All IDT71256SA12YI8 units undergo pre-shipment inspection (PSI). If there is an issue with IDT71256SA12YI8, 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 IDT71256SA12YI8 part is unused and in its original packaging.
Return procedure for IDT71256SA12YI8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
IDT71256SA12YI8 Tags
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