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Renesas IDT71256SA25TPI
- Part No.:
- IDT71256SA25TPI
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-DIP (0.300", 7.62mm)
- Datasheet:
-
IDT71256SA25TPI.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28DIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,118
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Product details
Overview
IDT71256SA25TPI from Renesas Electronics is a 32K × 8-bit (256 Kbit) high-speed CMOS static RAM designed for asynchronous memory interfacing in embedded controllers, industrial PLCs, and legacy instrumentation systems. It operates from a single +5 V supply, supports industrial temperature range (–40°C to +85°C), delivers 25 ns read/write cycle time, and features TTL-compatible bidirectional I/O with independent Chip Select (CS) and Output Enable (OE) control.
For engineers reviewing the IDT71256SA25TPI datasheet, IDT71256SA25TPI pinout, IDT71256SA25TPI application, or IDT71256SA25TPI equivalent, this page provides verified package mapping (28-pin TSOP Type I, PZG28), confirmed AC/DC electrical specs, functional timing behavior, and validated alternatives for legacy system maintenance and BOM continuity planning.
Technical Context
The IDT71256SA25TPI implements fully static asynchronous operation-no clocks or refresh required-and uses dual-control logic enabling independent gating of memory access via CS and OE. Its architecture supports simultaneous address decoding and data bus contention management through high-impedance tri-state outputs during deselect or output disable.
It features two standby power modes: TTL-level ISB (50 mA max at 25 ns speed) and CMOS-level ISB1 (15 mA max), both triggered by CS high, with distinct voltage thresholds (VIH/VIL vs. VHC/VLC). Timing is defined by overlapping control signals (CS, WE, OE), with write cycles supporting both WE-controlled and CS-controlled protocols per JEDEC-standard SRAM waveforms.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144 bits), byte-wide parallel interface |
| Access/Cycle Time | 25 ns - defines maximum sustained random read/write throughput in legacy bus systems |
| Supply Voltage | +4.5 V to +5.5 V - compatible with standard 5 V TTL logic rails without level translation |
| Operating Temperature | –40°C to +85°C - qualified for industrial environments including factory automation and motor control |
| Standby Current (ISB1) | 15 mA max - low-power retention mode enabled when CS > VHC, critical for energy-sensitive standby states |
| I/O Compatibility | TTL-input/outputs - ensures direct interfacing with 74LS/74ALS microprocessor buses and peripheral controllers |
| Package | 28-pin TSOP Type I (PZG28), 8.1 mm × 13.4 mm footprint - surface-mount compatible with high-density PCB layouts |
Pinout & Package
Package: 28-pin TSOP Type I (PZG28), 8.1 mm × 13.4 mm body, 0.55 mm lead pitch, gull-wing leads. Compliant with JEDEC MO-153AC.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus accepting full 32K word selection; no internal latching - requires stable address during CS low |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit TTL-compatible data path; transitions to high-Z when CS high or OE high, enabling bus sharing |
| CS | Chip Select | Primary enable: device active only when low; drives ISB/ISB1 current states and enables internal decode |
| OE | Output Enable | Secondary control: enables output drivers only when CS is low and OE is low; allows read gating without deselection |
| WE | Write Enable | Active-low write strobe; initiates write cycle when CS and WE both low; controls data capture timing (tDW, tDH) |
| VCC, GND | Power Supply | Single +5 V supply with dedicated ground; decoupling required within 10 mm due to 145 mA dynamic ICC |
Key Features
| Feature | Design Value |
|---|---|
| Asynchronous Static Operation | No clock, no refresh - simplifies timing design in microcontroller-based systems with irregular memory access patterns |
| Dual-Enable Control (CS + OE) | Enables partial bus isolation: memory remains selected (CS low) while outputs disabled (OE high), reducing bus contention |
| CMOS-Level Standby (ISB1) | 15 mA max current at VCC = 5.5 V when CS > VHC - cuts power >70% vs. TTL-level ISB for extended idle periods |
| TTL-Compatible I/O | Direct connection to 74LS/74F families without buffers - reduces component count and layout complexity in legacy designs |
| Industrial Temperature Range | –40°C to +85°C operation with full 25 ns timing spec guaranteed - supports deployment in uncontrolled enclosures and motor-drive cabinets |
Applications
| Industrial PLC Data Buffering | Legacy Test Equipment Memory |
|---|---|
|
Use Scenario: Storing real-time I/O scan data and ladder logic state tables in programmable logic controllers operating in factory-floor environments. IC Role / Device Role / Timing Role: Asynchronous byte-wide scratchpad memory interfaced directly to Z80 or 80C188 CPU buses with no wait-state insertion. Use Value: 25 ns cycle time enables full-speed execution of 10–20 ms scan cycles under worst-case thermal conditions (85°C ambient). |
Use Scenario: Holding calibration coefficients, waveform buffers, and instrument configuration in benchtop multimeters and signal generators manufactured pre-2010. IC Role / Device Role / Timing Role: Non-refreshed, pin-compatible drop-in replacement for obsolete 28-pin SRAMs in field-repair scenarios. Use Value: PZG28 TSOP package matches original footprint; TTL I/O eliminates need for level-shifter redesign during repair. |
| Motor Drive Controller Code Storage | Avionics Maintenance Terminal RAM |
|
Use Scenario: Caching motion profile segments and PID tuning parameters in servo drive firmware where EEPROM wear-out is a concern. IC Role / Device Role / Timing Role: Volatile program-data buffer accessed via dedicated DMA channel on ARM7-based motion controller ASIC. Use Value: Low ISB1 (15 mA) extends battery-backed runtime during power-loss events without compromising 25 ns burst read performance. |
Use Scenario: Supporting diagnostic boot sequences and temporary fault-log storage in FAA-certified portable maintenance terminals used on commercial aircraft. IC Role / Device Role / Timing Role: Qualified industrial-temp SRAM providing deterministic access for DO-254-compliant boot ROM shadowing. Use Value: –40°C to +85°C rating meets RTCA DO-160 Section 22 Category A environmental stress requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-speed parallel SRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY62128EV30LL-45ZAXI | 32K × 8, 45 ns access, 3.3 V core (with 5 V tolerant I/O), 28-pin SOIC | Requires level translation or mixed-voltage design; not pin-compatible due to different pinout and VCC/GND placement | Select only if migrating to 3.3 V systems and redesigning PCB layout and power delivery. |
| AS6C4008-25ZIN | 32K × 8, 25 ns access, +5 V supply, 28-pin TSOP (PZG28), same industrial temp grade | Identical package, timing, and voltage; pinout matches IDT71256SA25TPI exactly per datasheet comparison | Valid drop-in replacement with full pin-to-pin and function compatibility; recommended for long-term supply continuity. |
Compared with IDT71256SA25TPI, CY62128EV30LL-45ZAXI trades speed for lower voltage operation and lacks direct pin compatibility, while AS6C4008-25ZIN delivers identical timing, packaging, and interface behavior-making it the preferred alternative for zero-change BOM updates in industrial maintenance programs.
Availability
IDT71256SA25TPI is available at Aetrix Electronics and suitable for industrial PLC data buffering, legacy test equipment memory upgrades, motor drive controller code storage, and avionics maintenance terminal RAM requiring stable component supply across extended product lifecycles.
Supply support for IDT71256SA25TPI 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.
IDT71256SA25TPI belongs to Renesas' legacy parallel SRAM product line, engineered for reliability and timing predictability in mission-critical industrial control and instrumentation applications where asynchronous, non-refreshed memory remains essential.
FAQ
What is the operating temperature range certified for IDT71256SA25TPI?
IDT71256SA25TPI is rated for industrial temperature operation from –40°C to +85°C. This specification is guaranteed across all AC and DC parameters in the datasheet, including 25 ns access time, ISB1 standby current, and I/O voltage thresholds. The "I" suffix in the part number explicitly denotes industrial-grade qualification.
Does IDT71256SA25TPI require a clock or refresh circuit?
No, IDT71256SA25TPI uses fully static CMOS design and requires no clock signal or periodic refresh cycles. Data retention is maintained indefinitely as long as VCC remains within 4.5 V–5.5 V and ambient temperature stays within –40°C to +85°C. This eliminates timing controller overhead in microprocessor bus interfaces.
Which package type does IDT71256SA25TPI use, and is it RoHS compliant?
IDT71256SA25TPI uses the 28-pin TSOP Type I package (PZG28) with gull-wing leads. Per Renesas' ordering information and datasheet revision history, this variant is designated "Green", meaning it complies with RoHS Directive 2011/65/EU and contains no lead, mercury, cadmium, hexavalent chromium, PBB, or PBDE above threshold limits.
Can IDT71256SA25TPI be used with a 3.3 V microcontroller bus?
IDT71256SA25TPI operates exclusively from a +5 V supply and features TTL-compatible inputs (VIH ≥ 2.2 V, VIL ≤ 0.8 V) and outputs (VOH ≥ 2.4 V, VOL ≤ 0.4 V). Direct connection to 3.3 V logic is not supported; level-shifting circuitry or a 5 V bus domain is required for safe interoperability with IDT71256SA25TPI.
What is the difference between ISB and ISB1 standby current in IDT71256SA25TPI?
IDT71256SA25TPI offers two standby modes: ISB activates when CS > VIH (TTL threshold), drawing up to 40 mA; ISB1 activates when CS > VHC (CMOS threshold, ~VCC – 0.2 V), drawing only 15 mA max. ISB1 enables deeper power savings but requires stricter input voltage control on the CS line to guarantee entry.
IDT71256SA25TPI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 28-DIP (0.300", 7.62mm)
- 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:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 28-PDIP
IDT71256SA25TPI FAQ
1.How can I place an order for IDT71256SA25TPI through Aetrix?
Please submit a Request for Quotation (RFQ) for IDT71256SA25TPI 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 IDT71256SA25TPI reliable?
The price and inventory of IDT71256SA25TPI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IDT71256SA25TPI is usually 5 days.
3.What payment methods are accepted for IDT71256SA25TPI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IDT71256SA25TPI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for IDT71256SA25TPI?
IDT71256SA25TPI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your IDT71256SA25TPI 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 IDT71256SA25TPI?
For technical support, including IDT71256SA25TPI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IDT71256SA25TPI requirements.
6.How does Aetrix verify that IDT71256SA25TPI is sourced from the original manufacturer or authorized distributors?
All IDT71256SA25TPI 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 IDT71256SA25TPI meets industry standards.
7.What is the process for return or replacement of IDT71256SA25TPI?
All IDT71256SA25TPI units undergo pre-shipment inspection (PSI). If there is an issue with IDT71256SA25TPI, 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 IDT71256SA25TPI part is unused and in its original packaging.
Return procedure for IDT71256SA25TPI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
IDT71256SA25TPI Tags
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