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Renesas IDT71256SA20PZI8
- Part No.:
- IDT71256SA20PZI8
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-TSSOP (0.465", 11.80mm Width)
- Datasheet:
-
IDT71256SA20PZI8.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28TSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,113
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Product details
Overview
IDT71256SA20PZI8 from Renesas Electronics is a 32K × 8-bit (262,144-bit) high-speed CMOS static RAM operating at 5V, with 20 ns access time, industrial temperature range (–40°C to +85°C), TTL-compatible I/O, and single-chip-select architecture. It serves as main or cache memory in embedded controllers, industrial PLCs, and legacy instrumentation requiring deterministic, no-refresh asynchronous operation.
For engineers reviewing the IDT71256SA20PZI8 datasheet, IDT71256SA20PZI8 pinout, IDT71256SA20PZI8 application, or IDT71256SA20PZI8 equivalent, key selection criteria include industrial-grade timing consistency, low standby current (15 mA at CMOS-level deselect), TSOP-28 package compatibility, and direct replacement feasibility for legacy 256K SRAM designs in space-constrained PCBs.
Technical Context
The IDT71256SA20PZI8 implements fully static asynchronous circuitry-no clocks or refresh required-with independent chip select (CS) and output enable (OE) controls enabling flexible bus arbitration. Its bidirectional I/O pins support TTL-level voltage thresholds (VIH = 2.2 V min, VIL = 0.8 V max) and drive ±4 mA/±8 mA loads under specified conditions.
Timing is defined by overlapping control signals: read cycles require CS and OE both low (tAA = 20 ns, tOE = 10 ns); write cycles require CS and WE both low (tWC = 20 ns, tWP = 15 ns). Power states are managed via CS-driven transitions between active (ICC = 145 mA) and two standby modes (ISB = 40 mA, ISB1 = 15 mA).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144-bit total); supports byte-wide data bus interfacing without external demultiplexing |
| Access Time (tAA) | 20 ns maximum; guarantees valid data at I/O pins within 20 ns of stable address and CS assertion |
| Supply Voltage | 4.5 V to 5.5 V; compatible with standard 5V TTL logic rails and tolerant of ±10% regulation variation |
| Operating Temperature | –40°C to +85°C; qualified for industrial environments including factory automation and outdoor telemetry |
| Standby Current (ISB1) | 15 mA maximum at CMOS-level chip deselect (CS > VHC); enables ultra-low-power sleep mode in battery-backed systems |
| I/O Compatibility | TTL-compatible inputs and outputs; interfaces directly with 74LS, 74F, and microcontroller GPIO without level-shifting |
| Package | 28-pin TSOP Type I (PZG28); 8.1 mm × 13.4 mm footprint optimized for high-density PCB layouts |
Pinout & Package
Package: 28-pin TSOP Type I (PZG28), 8.1 mm × 13.4 mm body, 0.55 mm pitch, gull-wing leads, RoHS-compliant green construction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus accepting 0–32767; fully decoded internally to select one of 32K memory locations |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit parallel data path; direction controlled by CS and WE; high-impedance when deselected or during write |
| CS | Chip Select | Active-low enable; places device in active or standby mode; determines ISB vs ISB1 current consumption |
| WE | Write Enable | Active-low control; initiates write cycle when CS is also low; disables outputs during write to prevent bus contention |
| OE | Output Enable | Active-low control; enables read data output only when CS is low; allows fast 10 ns output enable independent of address setup |
| VCC | Power Supply | +5V supply pin; must be decoupled locally with 0.1 µF ceramic capacitor per device |
| GND | Ground | Signal and power reference; requires low-impedance connection to system ground plane |
Key Features
| Feature | Design Value |
|---|---|
| Asynchronous Static Operation | No clock, no refresh required-simplifies timing design and eliminates hidden refresh overhead in real-time systems |
| Dual Control Enable (CS + OE) | Enables independent gating of chip activation and output driver control-critical for multi-master bus arbitration |
| Low ISB1 Standby Current | 15 mA at CMOS-level deselect allows extended battery operation in backup memory applications |
| TTL-Compatible Interface | Direct connection to legacy microcontrollers (e.g., 8051, Z80) and logic families without interface buffers or level shifters |
| Industrial Temperature Qualification | Guaranteed 20 ns timing across –40°C to +85°C-ensures deterministic performance in uncontrolled thermal environments |
Applications
| Industrial PLC Memory Buffer | Legacy Instrumentation Data Cache |
|---|---|
Use Scenario: Storing real-time sensor readings and control state variables in programmable logic controllers deployed on factory floors. IC Role / Device Role / Timing Role: Non-volatile buffer memory holding intermediate process values between scan cycles; accessed asynchronously by CPU without wait states. Use Value: 20 ns access time ensures sub-microsecond response to I/O interrupts; industrial temp rating prevents timing drift during thermal cycling in enclosures. | Use Scenario: Caching waveform samples and calibration coefficients in benchtop oscilloscopes and spectrum analyzers with aging digital subsystems. IC Role / Device Role / Timing Role: High-reliability scratchpad memory for firmware-managed data buffering; replaces obsolete SRAMs in field-serviceable equipment. Use Value: TSOP-28 package fits legacy board footprints; TTL compatibility avoids redesign of FPGA or ASIC interface logic. |
| Embedded Controller Boot RAM | Communications Protocol Stack Buffer |
Use Scenario: Providing fast initialization RAM for boot code execution in microcontroller-based motor drives before external DRAM initialization. IC Role / Device Role / Timing Role: On-chip execution memory mapped into CPU address space; accessed during cold start with zero-latency deterministic timing. Use Value: Fully static operation eliminates boot-time refresh delays; 5V supply matches legacy MCU core voltage requirements. | Use Scenario: Holding packetized protocol data (e.g., Modbus RTU, CANopen) in gateway devices bridging legacy fieldbus networks to Ethernet. IC Role / Device Role / Timing Role: Dual-port accessible buffer supporting simultaneous receive/transmit DMA channels via CS/OE sequencing. Use Value: Independent OE control allows concurrent read/write operations across separate bus segments; 15 mA ISB1 reduces idle power in always-on gateways. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar static RAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY62128EV30LL-45ZSXIT | 32K × 8-bit, 45 ns access, 3.3V supply, industrial temp, SOIC-28 | Requires 3.3V rail and level translation for 5V systems; slower timing limits use in high-throughput control loops | Select only if migrating to 3.3V architecture and timing budget permits ≥45 ns latency |
| AS6C4008-20ZIN | 512K × 8-bit, 20 ns access, 5V supply, industrial temp, TSOP-32 | Double density but larger 32-pin TSOP footprint; incompatible pinout and address bus width (19-bit vs 15-bit) | Consider for capacity upgrade paths where board layout allows rework and firmware supports extended addressing |
Compared with CY62128EV30LL-45ZSXIT and AS6C4008-20ZIN, the IDT71256SA20PZI8 uniquely balances 5V TTL compatibility, 20 ns industrial-grade timing, and 28-pin TSOP footprint-making it the only drop-in solution for maintaining legacy 256K SRAM functionality without voltage or layout changes.
Availability
IDT71256SA20PZI8 is available at Aetrix Electronics and suitable for industrial PLCs, legacy instrumentation, embedded controller boot memory, and communications protocol stack buffering requiring stable component supply across extended product lifecycles.
Supply support for IDT71256SA20PZI8 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 IoT applications.
The IDT71256SA20PZI8 belongs to Renesas' legacy high-speed CMOS SRAM product line, designed specifically for backward-compatible replacement of aging 256K asynchronous memory in mission-critical industrial and test equipment.
FAQ
What is the operating voltage range for the IDT71256SA20PZI8?
The IDT71256SA20PZI8 operates over a supply voltage range of 4.5 V to 5.5 V, fully compliant with standard 5V TTL logic specifications. This range accommodates typical power supply tolerances and ensures reliable interface with legacy 5V microcontrollers and peripheral ICs without external regulation. The IDT71256SA20PZI8 maintains full timing specification compliance across this entire range.
Does the IDT71256SA20PZI8 require a clock or refresh signal?
No, the IDT71256SA20PZI8 uses fully static CMOS circuitry and requires neither a clock nor periodic refresh cycles. Its asynchronous operation means data retention is guaranteed as long as power and valid control signals (CS, WE, OE) are maintained-making it ideal for deterministic real-time systems where hidden refresh latency is unacceptable. This behavior is intrinsic to the IDT71256SA20PZI8 architecture.
What is the significance of ISB1 versus ISB in the IDT71256SA20PZI8 datasheet?
ISB (40 mA) applies when CS is driven to a TTL-high level (>2.2 V), while ISB1 (15 mA) applies when CS is driven to a CMOS-high level (>VCC – 0.2 V). The lower ISB1 current enables deeper power savings in systems where the host controller can assert a rail-aligned high level on CS. This dual-mode standby capability is a defined feature of the IDT71256SA20PZI8 and improves energy efficiency in battery-backed or thermally constrained deployments.
Can the IDT71256SA20PZI8 be used as a direct replacement for the IDT71256SA20PZG?
Yes-the IDT71256SA20PZI8 and IDT71256SA20PZG share identical speed grade (20 ns), package (TSOP-28 PZG28), and pinout; the only difference is temperature grading (industrial vs commercial). The IDT71256SA20PZI8 is functionally and electrically compatible with the commercial version across its full industrial range, making it a seamless upgrade for systems requiring extended thermal reliability without hardware modification.
What does the '8' suffix in IDT71256SA20PZI8 indicate?
The '8' suffix in IDT71256SA20PZI8 denotes tape-and-reel packaging-specifically, 1,000 units per reel-optimized for automated SMT assembly. This differs from the tube-packaged IDT71256SA20PZGI variant. The '8' has no effect on electrical performance, timing, or thermal specification; the IDT71256SA20PZI8 remains functionally identical to non-'8' variants in all operational respects.
IDT71256SA20PZI8 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 28-TSSOP (0.465", 11.80mm 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:
- 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-TSOP
IDT71256SA20PZI8 FAQ
1.How can I place an order for IDT71256SA20PZI8 through Aetrix?
Please submit a Request for Quotation (RFQ) for IDT71256SA20PZI8 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 IDT71256SA20PZI8 reliable?
The price and inventory of IDT71256SA20PZI8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IDT71256SA20PZI8 is usually 5 days.
3.What payment methods are accepted for IDT71256SA20PZI8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IDT71256SA20PZI8 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for IDT71256SA20PZI8?
IDT71256SA20PZI8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your IDT71256SA20PZI8 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 IDT71256SA20PZI8?
For technical support, including IDT71256SA20PZI8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IDT71256SA20PZI8 requirements.
6.How does Aetrix verify that IDT71256SA20PZI8 is sourced from the original manufacturer or authorized distributors?
All IDT71256SA20PZI8 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 IDT71256SA20PZI8 meets industry standards.
7.What is the process for return or replacement of IDT71256SA20PZI8?
All IDT71256SA20PZI8 units undergo pre-shipment inspection (PSI). If there is an issue with IDT71256SA20PZI8, 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 IDT71256SA20PZI8 part is unused and in its original packaging.
Return procedure for IDT71256SA20PZI8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
IDT71256SA20PZI8 Tags
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M24C02-WMN6TP
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AT24C02C-XHM-T
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AT24C08C-STUM-T
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