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Renesas IDT71256TTSA25Y
- Part No.:
- IDT71256TTSA25Y
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-BSOJ (0.300", 7.62mm Width)
- Datasheet:
-
IDT71256TTSA25Y.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28SOJ
- Quantity:
- Payment:
- Shipping:
Inventory:3,758
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Product details
Overview
IDT71256TTSA25Y from Renesas Electronics is a 32K × 8-bit (262,144-bit) high-speed CMOS static RAM with 25 ns access time, industrial temperature range (–40°C to +85°C), TTL-compatible I/O, single 5 V supply operation, and TSOP-28 package. It serves as main or cache memory in embedded controllers, legacy industrial PLCs, and instrumentation systems requiring deterministic asynchronous read/write timing.
For engineers reviewing the IDT71256TTSA25Y datasheet, IDT71256TTSA25Y pinout, IDT71256TTSA25Y application, or IDT71256TTSA25Y equivalent, key selection criteria include guaranteed tAA ≤ 25 ns at –40°C to +85°C, ISB1 standby current of 15 mA max, dual chip select control logic, and compatibility with legacy 5 V bus architectures without level translation.
Technical Context
The IDT71256TTSA25Y implements fully static asynchronous circuitry-no clocks or refresh required-and uses TTL-compatible input thresholds (VIH ≥ 2.2 V, VIL ≤ 0.8 V) with bidirectional data I/O pins. Its control logic supports both CS-controlled and WE-controlled write cycles, with tWP minimum of 20 ns and tDW of 13 ns.
It features two standby modes: ISB (TTL-level CS deassertion, 40 mA max) and ISB1 (CMOS-level CS deassertion, 15 mA max), enabling power optimization in battery-backed or low-duty-cycle systems. Address decoding is internal, with 15 address inputs (A0–A14) selecting one of 32,768 locations.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144-bit total); supports byte-wide data transfers without multiplexing |
| Access Time (tAA) | 25 ns max over –40°C to +85°C; ensures deterministic timing for real-time firmware execution |
| Supply Voltage | 4.5 V to 5.5 V; compatible with standard 5 V logic rails and tolerant of ±10% regulation variation |
| Standby Current (ISB1) | 15 mA max at VCC = 5.5 V, f = 0; enables ultra-low-power hold mode when CS > VHC |
| I/O Compatibility | TTL-compatible inputs/outputs; eliminates need for external level shifters in 5 V systems |
| Operating Temperature | –40°C to +85°C industrial grade; qualified for deployment in factory automation and outdoor telemetry |
| Package | 28-pin TSOP Type I (PZG28); 8.1 mm × 13.4 mm footprint, surface-mount compatible |
Pinout & Package
Package: 28-pin TSOP Type I (PZG28), 8.1 mm × 13.4 mm body, 0.5 mm pitch, gull-wing leads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus; selects one of 32,768 memory locations; no latching required |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit TTL-compatible data path; tri-stated when CS high or OE high during reads/writes |
| CS | Chip Select Input | Active-low enable; controls device selection and entry into ISB/ISB1 standby states |
| OE | Output Enable Input | Active-low; enables output drivers only during read cycles; tOE ≤ 11 ns ensures fast data assertion |
| WE | Write Enable Input | Active-low; initiates write cycle when CS low; supports WE-controlled or CS-controlled timing modes |
| VCC | Power Supply | +5 V supply pin; decoupling required within 10 mm of pin per high-speed RAM layout guidelines |
| GND | Ground Reference | Signal and power ground return; 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 microcontroller interfaces |
| Dual Standby Modes (ISB / ISB1) | Reduces power by up to 63% vs ISB when using CMOS-level CS deassertion in low-duty-cycle systems |
| Guaranteed Industrial Temp Performance | All AC/DC specs-including tAA = 25 ns and ISB1 = 15 mA-fully characterized from –40°C to +85°C |
| TTL-Compatible I/O | Direct interface to legacy 5 V microcontrollers (e.g., Intel 80Cxx, Motorola 68xxx) without level-shifting components |
| Green Compliant Packaging | Lead-free, RoHS-compliant TSOP package; meets Renesas' "Restricted hazardous substance device" requirements |
Applications
| Industrial PLC Memory Expansion | Legacy Medical Instrument Data Buffer |
|---|---|
Use Scenario: Adding non-volatile-capable SRAM to a DIN-rail mounted PLC running cyclic scan logic with deterministic I/O update windows. IC Role / Device Role / Timing Role: Primary working memory for ladder logic execution stack and real-time I/O image storage. Use Value: 25 ns tAA guarantees sub-50 ns memory access within 100 µs scan cycles; ISB1 mode cuts background power during idle periods. |
Use Scenario: Storing calibrated sensor readings and intermediate waveform samples in portable ECG analyzers with battery backup. IC Role / Device Role / Timing Role: High-reliability buffer between ADC front-end and ARM7-based processing core. Use Value: TTL compatibility avoids signal integrity loss across long PCB traces; industrial temp rating ensures accuracy in uncontrolled clinical environments. |
| Avionics Test Equipment Firmware Cache | Ruggedized HMI Controller Frame Buffer |
Use Scenario: Caching FPGA configuration bitstreams and calibration tables in ground-support ATE used for flight controller validation. IC Role / Device Role / Timing Role: Fast-access local memory for boot-time configuration loading and runtime parameter lookup. Use Value: 28-pin TSOP package withstands thermal cycling in reflow-soldered ATE modules; tPD ≤ 25 ns enables rapid context switching. |
Use Scenario: Holding GUI bitmap frames and touch-screen coordinate buffers in marine-grade HMIs exposed to salt fog and wide ambient swings. IC Role / Device Role / Timing Role: Dual-port accessible frame store synchronized to display controller pixel clock. Use Value: Guaranteed –40°C to +85°C operation prevents frame corruption during cold starts or engine-bay heat soak. |
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-25ZSXI | 25 ns access, same 32K×8 organization, but uses 28-pin SOIC (not TSOP); ISB1 = 25 mA (vs 15 mA) | Preferred where board space allows wider SOIC footprint and higher standby current is acceptable | Select when existing layout uses SOIC pads and thermal budget permits +10 mA ISB1 increase |
| AS6C4008-25ZIN | 25 ns access, industrial temp, 28-pin TSOP, but lower ICC (135 mA vs 145 mA) and tighter VIH min (2.0 V) | Better suited for mixed-voltage systems with marginal 5 V rail stability or tighter power envelopes | Choose when optimizing for dynamic power in high-throughput logging applications |
Compared with IDT71256TTSA25Y, CY62256LL-25ZSXI trades TSOP compactness for SOIC ease-of-handling and higher standby draw, while AS6C4008-25ZIN offers lower active current and relaxed input threshold margins-making it more robust on noisy or aging 5 V supplies.
Availability
IDT71256TTSA25Y is available at Aetrix Electronics and suitable for industrial PLC upgrades, legacy medical instrument refurbishment, and avionics test equipment requiring stable component supply with full industrial temperature qualification and green-compliant packaging.
Supply support for IDT71256TTSA25Y 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 trusted embedded solutions for automotive, industrial, infrastructure, and IoT applications.
IDT71256TTSA25Y belongs to Renesas' legacy high-speed CMOS SRAM product line, designed specifically for drop-in replacement of obsolete 28-pin 5 V SRAMs in long-lifecycle industrial and instrumentation systems.
FAQ
What is the maximum guaranteed access time for IDT71256TTSA25Y across its full operating temperature range?
The IDT71256TTSA25Y has a maximum guaranteed address access time (tAA) of 25 ns over the full industrial temperature range of –40°C to +85°C, as specified in the AC Electrical Characteristics table under the 71256SA25 speed grade. This value is production-tested and applies to all valid VCC conditions (4.5 V to 5.5 V).
Does IDT71256TTSA25Y support true bidirectional data transfer without external direction control?
Yes, IDT71256TTSA25Y supports true bidirectional data transfer on I/O0–I/O7 pins. Direction is controlled internally by the combination of CS, OE, and WE signals-no external transceiver or direction pin is needed. During reads, outputs are enabled when CS and OE are low; during writes, inputs are active when CS and WE are low.
What is the difference between ISB and ISB1 standby current specifications for IDT71256TTSA25Y?
IDT71256TTSA25Y defines two standby modes: ISB (TTL-level CS deassertion, CS > VIH) draws ≤40 mA max, while ISB1 (CMOS-level CS deassertion, CS > VHC ≈ VCC – 0.2 V) draws ≤15 mA max. ISB1 delivers significantly lower power but requires stricter high-level voltage compliance on the CS line.
Is IDT71256TTSA25Y pin-compatible with earlier IDT71256SA variants in TSOP package?
Yes, IDT71256TTSA25Y maintains identical pinout, electrical behavior, and timing architecture with all IDT71256SA-series TSOP variants (e.g., IDT71256SA15PZGI, IDT71256SA20PZGI). The "TT" suffix denotes Renesas' rebranded version with updated documentation and green-compliance status-but no functional or mechanical changes.
Can IDT71256TTSA25Y operate reliably with a 4.75 V supply in an industrial environment?
Yes, IDT71256TTSA25Y is fully specified for VCC = 4.5 V to 5.5 V across –40°C to +85°C. At 4.75 V, all DC and AC parameters-including tAA ≤ 25 ns, VOH ≥ 2.4 V, and VOL ≤ 0.4 V-remain guaranteed per the datasheet's Recommended DC Operating Conditions and AC Electrical Characteristics tables.
IDT71256TTSA25Y 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:
- 25ns
- Access Time:
- 25 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
IDT71256TTSA25Y FAQ
1.How can I place an order for IDT71256TTSA25Y through Aetrix?
Please submit a Request for Quotation (RFQ) for IDT71256TTSA25Y 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 IDT71256TTSA25Y reliable?
The price and inventory of IDT71256TTSA25Y are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IDT71256TTSA25Y is usually 5 days.
3.What payment methods are accepted for IDT71256TTSA25Y?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IDT71256TTSA25Y transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for IDT71256TTSA25Y?
IDT71256TTSA25Y orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your IDT71256TTSA25Y 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 IDT71256TTSA25Y?
For technical support, including IDT71256TTSA25Y datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IDT71256TTSA25Y requirements.
6.How does Aetrix verify that IDT71256TTSA25Y is sourced from the original manufacturer or authorized distributors?
All IDT71256TTSA25Y 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 IDT71256TTSA25Y meets industry standards.
7.What is the process for return or replacement of IDT71256TTSA25Y?
All IDT71256TTSA25Y units undergo pre-shipment inspection (PSI). If there is an issue with IDT71256TTSA25Y, 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 IDT71256TTSA25Y part is unused and in its original packaging.
Return procedure for IDT71256TTSA25Y:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
IDT71256TTSA25Y Tags
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AT24C02C-XHM-T
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