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Renesas 71256SA12YG
- Part No.:
- 71256SA12YG
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-BSOJ (0.300", 7.62mm Width)
- Datasheet:
-
71256SA12YG.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28SOJ
- Quantity:
- Payment:
- Shipping:
Inventory:3,798
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Product details
Overview
71256SA12YG from Renesas Electronics is a 32K × 8-bit (256 Kbit) high-speed CMOS static RAM with 12 ns access time, TTL-compatible I/O, single 5 V supply operation, and industrial-grade SOJ-28 packaging. It serves as a non-refreshing, fully static memory buffer in embedded controllers, instrumentation data acquisition, and legacy industrial PLCs requiring deterministic timing.
For engineers reviewing the 71256SA12YG datasheet, 71256SA12YG pinout, 71256SA12YG application, or 71256SA12YG equivalent, this page delivers verified timing parameters, SOJ-28 terminal mapping, commercial-grade thermal specs, TTL-level interface behavior, and direct alternatives for memory upgrade paths in legacy 5 V systems.
Technical Context
The 71256SA12YG implements fully static asynchronous architecture-no clocks, no refresh cycles-enabling deterministic read/write latency critical for real-time control loops. Its dual-control enable scheme uses independent Chip Select (CS) and Output Enable (OE) pins to support interleaved memory access and bus contention management.
It operates exclusively at 5.0 V ±10% with VIH = 2.2 V min and VIL = 0.8 V max, ensuring robust noise margin in noisy industrial environments. Standby current drops to 50 mA (ISB) under TTL-level deselection and further to 15 mA (ISB1) under CMOS-level deselection, supporting low-power sleep modes without external power gating.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144-bit array), byte-wide parallel interface |
| Access Time (tAA) | 12 ns max - guarantees sub-83 MHz random read throughput in synchronous bus designs |
| Supply Voltage | 4.5 V to 5.5 V - compatible with standard 5 V TTL/CMOS logic rails without regulation |
| I/O Compatibility | TTL input thresholds (VIH ≥ 2.2 V, VIL ≤ 0.8 V) and output drive (VOH ≥ 2.4 V @ –4 mA, VOL ≤ 0.4 V @ 8 mA) |
| Operating Temperature | 0°C to +70°C - commercial grade only; not rated for industrial –40°C to +85°C operation |
| Package | 28-pin 300-mil Plastic SOJ (PJG28) - surface-mount compatible with wave-solder and reflow profiles |
| Standby Current (ISB) | 50 mA max - enables low-quiescent power state when CS = high, reducing system idle power |
Pinout & Package
71256SA12YG is housed in a 28-pin 300-mil Plastic SOJ (PJG28) package with gull-wing leads, designed for surface-mount assembly and compatible with JEDEC MS-012AC footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus accepting 0–32,767 row/column decode; fully static-no setup/hold timing required |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit TTL-compatible data path; high-impedance when CS = high or OE = high, enabling bus sharing |
| CS | Chip Select | Active-low enable controlling device selection; drives ISB = 50 mA standby current when high |
| OE | Output Enable | Active-low control of output drivers; enables fast 6 ns output valid timing independent of CS |
| WE | Write Enable | Active-low write strobe; initiates write cycle with tWP ≥ 8 ns minimum pulse width |
| VCC, GND | Power Supply | Single 5 V supply with decoupling recommended near pin 28 (VCC) and pin 14 (GND) |
Key Features
| Feature | Design Value |
|---|---|
| 12 ns Address Access Time | Enables deterministic read response within one clock cycle of a 83 MHz CPU bus without wait states |
| Dual Enable Architecture (CS + OE) | Allows independent control of chip selection and output driver activation-critical for multi-device bus arbitration |
| TTL-Compatible I/O | Eliminates level-shifting components when interfacing with legacy 5 V microcontrollers and FPGAs |
| Zero-Refresh Static Operation | Removes DRAM controller complexity and eliminates refresh overhead in real-time firmware stacks |
| SOJ-28 Surface-Mount Package | Supports automated placement and reflow soldering while maintaining compatibility with through-hole DIP layouts via adapter boards |
Applications
| Industrial Data Loggers | Legacy PLC Memory Buffers |
|---|---|
|
Use Scenario: Capturing sensor readings at 10 kHz in oil-field telemetry units with battery-backed SRAM retention. IC Role / Device Role / Timing Role: Primary volatile data buffer holding timestamped analog samples before flash transfer. Use Value: 12 ns tAA ensures full sample capture at maximum scan rate without CPU wait-state insertion. |
Use Scenario: Storing ladder logic state tables and I/O image registers in DIN-rail mounted programmable logic controllers. IC Role / Device Role / Timing Role: Non-refreshing working memory for scan-cycle execution with guaranteed deterministic access. Use Value: Fully static architecture eliminates refresh-induced jitter in 1 ms control loop timing. |
| Medical Instrumentation FIFOs | Avionics Display Frame Buffers |
|
Use Scenario: Acting as first-in-first-out buffer between ADC front-end and DSP engine in portable ECG analyzers. IC Role / Device Role / Timing Role: Synchronous read/write interface bridging 5 V analog subsystem and 3.3 V digital core via level shifters. Use Value: TTL-compatible I/O simplifies interface design while 12 ns access supports >80 MB/s sustained throughput. |
Use Scenario: Holding rasterized display data for monochrome cockpit displays in certified avionics modules. IC Role / Device Role / Timing Role: Dedicated frame buffer memory accessed by display controller during horizontal blanking intervals. Use Value: Sub-15 ns cycle time enables full VGA (640×480) frame load within vertical retrace window. |
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-45ZSXI | 32K × 8-bit, 45 ns access, 3.3 V supply, SOIC-28 package | Requires voltage translation for 5 V systems; slower but lower power and RoHS-compliant | Select when migrating to 3.3 V platforms or prioritizing power over speed |
| AS6C4008-12ZIN | 512K × 8-bit, 12 ns access, 5 V supply, SOJ-32 package | Higher density and same speed, but larger 32-pin SOJ footprint and higher ICC (200 mA) | Select when board layout allows SOJ-32 and application requires >256 Kbit capacity |
Compared with 71256SA12YG, CY62128EV30LL-45ZSXI trades speed for 3.3 V compatibility and lower quiescent power, while AS6C4008-12ZIN retains identical 12 ns timing but doubles capacity at the cost of pin count and supply current-neither is pin-compatible, requiring PCB revision.
Availability
71256SA12YG is available at Aetrix Electronics and suitable for industrial data loggers, legacy PLC memory buffers, and medical instrumentation FIFOs requiring stable component supply and long-term obsolescence management.
Supply support for 71256SA12YG 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 71256SA series was developed as a drop-in replacement for legacy 256 Kbit SRAMs in 5 V industrial control systems, emphasizing pin compatibility, TTL interoperability, and extended temperature reliability.
FAQ
What is the operating temperature range for the 71256SA12YG?
The 71256SA12YG is specified for commercial temperature operation only: 0°C to +70°C. Although other variants in the 71256SA family (e.g., 71256SA15YGI) support –40°C to +85°C, the 12 ns speed grade (71256SA12YG) is explicitly restricted to commercial grade per Renesas' ordering information and datasheet note on page 11/03/14 revision.
Does the 71256SA12YG require a refresh circuit?
No, the 71256SA12YG is a fully static RAM and requires no refresh circuitry. Its CMOS-based memory array retains data indefinitely as long as VCC is applied and CS remains active low during access-eliminating the need for external refresh controllers or timing-critical refresh cycles in firmware.
Can the 71256SA12YG be used with a 3.3 V microcontroller?
The 71256SA12YG is designed for 5 V operation (4.5–5.5 V) and features TTL-compatible inputs (VIH ≥ 2.2 V) and outputs (VOH ≥ 2.4 V). Direct connection to a 3.3 V MCU is not recommended without level translation, as its outputs exceed 3.3 V absolute maximum ratings and its inputs may not reliably recognize 3.3 V logic highs.
What is the meaning of "YG" in the part number 71256SA12YG?
In the Renesas 71256SA ordering nomenclature, "YG" denotes the 28-pin 300-mil Plastic SOJ package (PJG28). The "Y" identifies SOJ packaging, and "G" specifies green (lead-free, RoHS-compliant) construction-confirmed in the Ordering Information table on page 7 of the datasheet.
Is the 71256SA12YG still recommended for new designs?
Yes-the "Not recommended for new designs" notice was removed from the datasheet on 02/01/01 and has not been reinstated. The 71256SA12YG remains an active, supported product per Renesas' current documentation and distributor listings, with ongoing availability through authorized channels including Aetrix Electronics.
71256SA12YG 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:
- 12ns
- Access Time:
- 12 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
71256SA12YG FAQ
1.How can I place an order for 71256SA12YG through Aetrix?
Please submit a Request for Quotation (RFQ) for 71256SA12YG 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 71256SA12YG reliable?
The price and inventory of 71256SA12YG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71256SA12YG is usually 5 days.
3.What payment methods are accepted for 71256SA12YG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71256SA12YG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71256SA12YG?
71256SA12YG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71256SA12YG 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 71256SA12YG?
For technical support, including 71256SA12YG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71256SA12YG requirements.
6.How does Aetrix verify that 71256SA12YG is sourced from the original manufacturer or authorized distributors?
All 71256SA12YG 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 71256SA12YG meets industry standards.
7.What is the process for return or replacement of 71256SA12YG?
All 71256SA12YG units undergo pre-shipment inspection (PSI). If there is an issue with 71256SA12YG, 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 71256SA12YG part is unused and in its original packaging.
Return procedure for 71256SA12YG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71256SA12YG Tags
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M24C02-WMN6TP
STMicroelectronics
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AT24C02C-XHM-T
Microchip Technology
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AT21CS01-STUM10-T
Microchip Technology
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AT24C02C-SSHM-T
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24LC01BT-I/OT
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M24C02-FMC6TG
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AT24CS02-SSHM-T
Microchip Technology
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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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