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Renesas IDT71256SA25TP
- Part No.:
- IDT71256SA25TP
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-DIP (0.300", 7.62mm)
- Datasheet:
-
IDT71256SA25TP.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28DIP
- Quantity:
- Payment:
- Shipping:
Inventory:2,361
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Product details
Overview
IDT71256SA25TP from Renesas Electronics is a 32K × 8-bit (256 Kbit) high-speed CMOS static RAM with 25 ns access and cycle times, TTL-compatible I/O, single 5 V supply operation, and industrial-grade temperature support (–40°C to +85°C). It serves as a non-refreshing, asynchronous memory buffer in embedded controllers, legacy industrial PLCs, and real-time data acquisition systems requiring deterministic read/write timing.
For engineers reviewing the IDT71256SA25TP datasheet, IDT71256SA25TP pinout, IDT71256SA25TP application, or IDT71256SA25TP equivalent, key selection criteria include its 28-pin PDIP package, 25 ns industrial-speed timing, CMOS-level standby current (15 mA), and direct TTL interface compatibility without level-shifting.
Technical Context
The IDT71256SA25TP implements fully static asynchronous circuitry-no clocks or refresh required-and uses dual control logic for independent chip select (CS) and output enable (OE) assertion. Its bidirectional I/O architecture supports concurrent address latching and data transfer with guaranteed tCLZ ≤ 4 ns and tOHZ ≤ 10 ns under industrial conditions.
It operates across VCC = 4.5 V to 5.5 V with VIH ≥ 2.2 V and VIL ≤ 0.8 V, enabling robust interfacing with legacy 5 V microcontrollers and FPGAs. Standby modes include TTL-level (ISB = 40 mA) and CMOS-level (ISB1 = 15 mA) power-down, activated via CS voltage thresholds (VIH/VHC).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144-bit array), no refresh required |
| Access Time (tAA) | 25 ns max - guarantees deterministic read latency in real-time control loops |
| Cycle Time (tRC) | 25 ns max - enables sustained 40 MHz burst read/write throughput |
| Supply Voltage | 4.5 V to 5.5 V - compatible with standard 5 V logic rails and tolerant of ±10% regulation |
| Standby Current (ISB1) | 15 mA max at CMOS-level CS - reduces idle power in battery-backed or low-duty-cycle systems |
| Operating Temperature | –40°C to +85°C - qualified for industrial automation and transportation electronics |
| I/O Compatibility | TTL input thresholds and output drive - interfaces directly with 80Cxx, Z80, and 68K-family processors |
Pinout & Package
Package: 28-pin 300-mil Plastic Dual In-line Package (PDIP), part code PTG28 per Renesas ordering guide.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus supporting full 32K word decoding; no internal multiplexing |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit TTL-compatible data path; high-impedance when CS or OE inactive |
| CS | Chip Select | Active-low enable; controls both power state (ISB/ISB1) and output driver activation |
| OE | Output Enable | Active-low; gates output drivers independently of CS for shared-bus timing control |
| WE | Write Enable | Active-low; initiates write cycle when CS is active; disables outputs during write |
| VCC, GND | Power Supply | Single 5 V supply; decoupling required per JEDEC standards for 25 ns operation |
Key Features
| Feature | Design Value |
|---|---|
| Asynchronous Static Operation | No clock, no refresh, no wait states - simplifies timing-critical MCU/FPGA memory interfaces |
| Dual Control Logic (CS + OE) | Enables precise bus sharing: OE toggles outputs without exiting standby, reducing power transitions |
| CMOS-Level Standby (ISB1) | 15 mA max current at VCC = 5.5 V and CS > VHC - cuts standby power by 62.5% vs TTL-level mode |
| TTL-Compatible I/O | Direct connection to legacy 5 V microprocessors without level shifters or pull-ups |
| Industrial Temperature Range | –40°C to +85°C operation validated per Renesas qualification standards for extended life in harsh environments |
Applications
| Industrial PLC Data Buffer | Legacy Microcontroller Memory Expansion |
|---|---|
Use Scenario: Storing real-time I/O scan data and ladder logic variables in programmable logic controllers operating in factory-floor environments. IC Role / Device Role / Timing Role: Asynchronous SRAM providing zero-wait-state read/write access for deterministic scan-cycle execution. Use Value: 25 ns access time ensures sub-100 µs I/O update cycles; industrial temp rating maintains reliability at 70°C ambient cabinet temperatures. | Use Scenario: Adding external program/data memory to Z80- or 8085-based embedded systems where on-chip RAM is insufficient. IC Role / Device Role / Timing Role: Pin-compatible 8-bit parallel memory mapped into CPU address space using standard address decode logic. Use Value: TTL-compatible I/O eliminates need for bus transceivers; 28-pin PDIP fits legacy through-hole PCB layouts. |
| Real-Time Data Acquisition Buffer | Avionics Maintenance Terminal Memory |
Use Scenario: Capturing high-speed analog-to-digital conversion results in test equipment before host processor transfer. IC Role / Device Role / Timing Role: High-reliability static buffer holding burst-sampled data until DMA or polling reads complete. Use Value: Fully static design prevents data loss during CPU interrupts; 15 mA ISB1 enables low-power sleep between acquisition bursts. | Use Scenario: Storing diagnostic firmware and configuration tables in portable avionics ground support terminals. IC Role / Device Role / Timing Role: Non-volatile-supporting volatile memory used for fast boot-time code decompression and runtime variable storage. Use Value: Industrial temp range meets DO-160 Section 22 thermal shock requirements; green (RoHS-compliant) variant available per ordering code suffix. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar static RAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY62256LN-25ZSXIT | Same 32K × 8 organization, 25 ns speed, but 32-pin SOIC package; lower ISB1 (5 mA) | Requires PCB redesign for surface-mount layout; better suited for new designs targeting higher density | Select when migrating from through-hole to SMT and lower standby current is critical |
| AS6C4008-25ZIN | 25 ns speed, 32K × 8, 28-pin SOJ package; higher ICC (160 mA vs 145 mA) and no industrial temp option | Limited to commercial grade (0°C to +70°C); unsuitable for extended-temperature deployments | Select only for cost-sensitive commercial applications where industrial qualification is unnecessary |
Compared with CY62256LN-25ZSXIT and AS6C4008-25ZIN, the IDT71256SA25TP uniquely combines 28-pin PDIP packaging, verified –40°C to +85°C operation, and 15 mA CMOS-level standby-making it the sole drop-in replacement for legacy industrial systems requiring mechanical and thermal compatibility without layout change.
Availability
IDT71256SA25TP is available at Aetrix Electronics and suitable for industrial automation, legacy system repair, and avionics ground support equipment requiring stable component supply and long-term lifecycle assurance.
Supply support for IDT71256SA25TP 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 IDT71256SA25TP belongs to Renesas' legacy high-speed CMOS SRAM product line, designed specifically for backward-compatible memory expansion in industrial control, test instrumentation, and aerospace maintenance systems requiring proven reliability and long-lifecycle support.
FAQ
What is the maximum operating frequency supported by the IDT71256SA25TP?
The IDT71256SA25TP does not operate on a clock signal-it is an asynchronous SRAM. Its maximum effective throughput is determined by its 25 ns cycle time (tRC), enabling up to 40 million read/write operations per second in burst mode. Timing is governed solely by address and control signal setup/hold requirements, not by a system clock.
Does the IDT71256SA25TP require a refresh circuit or external clock?
No, the IDT71256SA25TP is a fully static RAM and requires neither refresh circuitry nor an external clock. Its internal CMOS latches retain data indefinitely as long as VCC is applied and CS remains asserted during active use. This eliminates timing overhead and simplifies integration with microcontrollers lacking DRAM controllers.
Can the IDT71256SA25TP be used with 3.3 V microcontrollers?
The IDT71256SA25TP is specified for 4.5 V to 5.5 V operation and features TTL-compatible inputs (VIH ≥ 2.2 V, VIL ≤ 0.8 V). While its inputs may accept 3.3 V logic HIGH, its outputs swing to 5 V levels and are not 3.3 V-tolerant. Direct interfacing with 3.3 V systems requires level translation or bus buffers to prevent damage or signal integrity issues.
What is the difference between ISB and ISB1 standby current in the IDT71256SA25TP?
ISB (40 mA max) is the standby current when CS is pulled above VIH (≥2.2 V), typical of TTL-level control. ISB1 (15 mA max) is the reduced standby current achieved when CS is driven above VHC (VCC – 0.2 V), enabling deeper power savings in systems with CMOS-compatible control logic. Both modes place outputs in high-impedance state.
Is the IDT71256SA25TP RoHS-compliant and halogen-free?
Yes, the IDT71256SA25TP is a green part per Renesas' ordering information-compliant with RoHS Directive 2011/65/EU and halogen-free per IEC 61249-2-21. The "G" suffix in package codes (e.g., PTG28) denotes green material set; this applies to all currently shipped IDT71256SA25TP units.
IDT71256SA25TP 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:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 28-PDIP
IDT71256SA25TP FAQ
1.How can I place an order for IDT71256SA25TP through Aetrix?
Please submit a Request for Quotation (RFQ) for IDT71256SA25TP 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 IDT71256SA25TP reliable?
The price and inventory of IDT71256SA25TP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IDT71256SA25TP is usually 5 days.
3.What payment methods are accepted for IDT71256SA25TP?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IDT71256SA25TP transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for IDT71256SA25TP?
IDT71256SA25TP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your IDT71256SA25TP 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 IDT71256SA25TP?
For technical support, including IDT71256SA25TP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IDT71256SA25TP requirements.
6.How does Aetrix verify that IDT71256SA25TP is sourced from the original manufacturer or authorized distributors?
All IDT71256SA25TP 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 IDT71256SA25TP meets industry standards.
7.What is the process for return or replacement of IDT71256SA25TP?
All IDT71256SA25TP units undergo pre-shipment inspection (PSI). If there is an issue with IDT71256SA25TP, 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 IDT71256SA25TP part is unused and in its original packaging.
Return procedure for IDT71256SA25TP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
IDT71256SA25TP Tags
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M24C02-WMN6TP
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AT24C02C-XHM-T
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AT21CS01-STUM10-T
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24LC01BT-I/OT
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M24C02-FMC6TG
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AT24CS02-SSHM-T
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93LC46BT-I/OT
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AT24C04C-SSHM-T
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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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