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Renesas 71256SA15YG
- Part No.:
- 71256SA15YG
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-BSOJ (0.300", 7.62mm Width)
- Datasheet:
-
71256SA15YG.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28SOJ
- Quantity:
- Payment:
- Shipping:
Inventory:1,025
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Product details
Overview
71256SA15YG from Renesas Electronics is a 32K × 8-bit (256 Kbit) high-speed CMOS static RAM with 15 ns access time, TTL-compatible I/O, single 5 V supply operation, and industrial-grade temperature range support (–40°C to +85°C). It features separate Chip Select (CS) and Output Enable (OE) pins, bidirectional data bus, and low-power standby modes - deployed in embedded controllers, legacy industrial PLCs, and real-time data buffering systems.
For engineers reviewing the 71256SA15YG datasheet, 71256SA15YG pinout, 71256SA15YG application, or 71256SA15YG equivalent, key selection criteria include verified 15 ns read/write cycle timing, SOJ-28 package compatibility, TTL-level interface robustness, and industrial-temperature reliability without refresh circuitry.
Technical Context
The 71256SA15YG implements fully static asynchronous memory architecture with no clocks or refresh required. Its control logic decodes 15 address lines (A0–A14) to select one of 32,768 locations, each delivering or accepting 8-bit parallel data via I/O0–I/O7.
It supports two distinct standby states: ISB (TTL-level CS deassertion, 40 mA max ICC) and ISB1 (CMOS-level CS deassertion, 15 mA max ICC), enabling dynamic power scaling based on system-level voltage thresholds and timing margins.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144 bits), fixed parallel interface |
| Access Time (tAA) | 15 ns maximum - defines minimum address-to-data-valid delay in read cycles |
| Read Cycle Time (tRC) | 15 ns minimum - sets shortest interval between successive read operations |
| Supply Voltage | 4.5 V to 5.5 V - compatible with standard 5 V TTL/CMOS logic rails |
| Operating Temperature | –40°C to +85°C - qualified for industrial environments without derating |
| Package | 28-pin 300-mil Plastic SOJ (PJG28) - surface-mount compatible with legacy reflow profiles |
| Input/Output Compatibility | TTL-level - ensures direct interfacing with 74LS/74ALS and microcontroller GPIO without level shifters |
Pinout & Package
71256SA15YG is housed in a 28-pin 300-mil Plastic SOJ (PJG28) package with gull-wing leads, designed for wave or reflow soldering in space-constrained industrial PCBs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit binary address bus selecting one of 32,768 memory locations |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit parallel path for read data output or write data input; TTL-compatible drive strength |
| CS | Chip Select | Active-low enable controlling device activation and standby current mode (ISB/ISB1) |
| OE | Output Enable | Active-low control for data bus output drivers; enables fast 7 ns output valid timing |
| WE | Write Enable | Active-low signal initiating write cycles; synchronizes data latching with address and CS |
| VCC, GND | Power Supply | Single 5 V supply with dedicated ground pin; decoupling required per high-speed RAM layout rules |
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 Standby Current Modes | ISB = 40 mA (TTL CS threshold), ISB1 = 15 mA (CMOS CS threshold) - enables software-selectable power savings |
| Fast Output Enable | 7 ns tOE - supports tight timing budgets in high-throughput data acquisition buffers |
| Industrial Temperature Qualification | –40°C to +85°C operation with full AC/DC specs guaranteed - eliminates thermal derating in factory-floor deployments |
| Green Packaging Option | Lead-free, RoHS-compliant construction - meets modern environmental compliance requirements without performance trade-offs |
Applications
| Industrial PLC Data Buffer | Legacy Microcontroller Memory Expansion |
|---|---|
Use Scenario: Real-time I/O scanning in programmable logic controllers where deterministic memory latency is critical for scan-cycle consistency. IC Role / Device Role / Timing Role: Off-chip SRAM providing non-refreshed, byte-wide scratchpad storage for process image tables and intermediate logic results. Use Value: 15 ns tAA and tRC ensure sub-30 ns memory turnaround - directly supporting 33 MHz bus timing in Z80/80C188-based control engines. | Use Scenario: Adding external RAM to 8-bit or 16-bit microcontrollers (e.g., Intel 8051, Motorola 68HC11) with limited on-die memory. IC Role / Device Role / Timing Role: Parallel memory extension mapped into the processor's external address space using standard address/data bus demultiplexing. Use Value: TTL-compatible I/O and 5 V operation eliminate level-shifting components - reducing BOM count and board area in cost-sensitive designs. |
| Embedded Instrumentation FIFO | Avionics Health Monitor Buffer |
Use Scenario: Capturing high-speed sensor samples (e.g., ADC streams) in portable test equipment requiring glitch-free burst reads. IC Role / Device Role / Timing Role: Dual-port-like behavior enabled by fast OE/CS sequencing - used as a ping-pong buffer without external arbitration logic. Use Value: 4 ns tCLZ and 6 ns tOHZ allow rapid bus release and capture - enabling >25 MHz effective throughput in burst-mode sampling. | Use Scenario: Storing diagnostic telemetry in airborne health monitoring units operating across extended thermal ranges. IC Role / Device Role / Timing Role: Radiation-tolerant-adjacent memory storing flight-critical status logs with guaranteed retention at –40°C and +85°C. Use Value: Industrial-grade qualification and 15 mA ISB1 current support long-duration battery-backed operation during aircraft standby phases. |
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 | 512K × 8-bit, 45 ns access, 3.3 V only, TSOP-32 | Higher density but slower speed and incompatible voltage - requires level translation and board redesign | Select only if migrating to 3.3 V systems and needing >256 Kbit capacity |
| AS6C4008-55ZIN | 512K × 8-bit, 55 ns access, 5 V tolerant, SOJ-32 | Same voltage, larger capacity, but 55 ns timing - unsuitable for 15 ns-critical paths | Acceptable for non-real-time logging where latency < 55 ns is sufficient |
Compared with CY62128EV30LL-45ZSXIT and AS6C4008-55ZIN, the 71256SA15YG delivers precise 15 ns timing at 5 V in SOJ-28 - making it irreplaceable in legacy industrial designs where pinout, voltage, and speed are jointly constrained.
Availability
71256SA15YG is available at Aetrix Electronics and suitable for industrial PLCs, legacy microcontroller systems, embedded instrumentation, and avionics health monitors requiring stable component supply across extended lifecycle programs.
Supply support for 71256SA15YG 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 specializing in microcontrollers, analog, power, and memory solutions for industrial, automotive, and infrastructure markets.
The 71256SA product line delivers high-reliability, pin-compatible static RAMs optimized for legacy system maintenance and long-lifecycle industrial deployments - emphasizing timing precision, temperature resilience, and drop-in replaceability.
FAQ
What is the operating voltage range for the 71256SA15YG?
The 71256SA15YG operates from 4.5 V to 5.5 V DC. This 5 V nominal range ensures full compatibility with legacy TTL and CMOS logic families without level-shifting circuitry. All AC and DC specifications - including 15 ns access time and 40 mA ISB current - are guaranteed across this voltage window at industrial temperatures.
Does the 71256SA15YG require a clock or refresh signal?
No, the 71256SA15YG uses fully static CMOS memory cells and requires neither a clock nor periodic refresh. Its asynchronous design allows random read/write access at any time, provided address and control signals meet setup/hold timing. This eliminates timing controller overhead in microcontroller-based systems and reduces system-level complexity.
What package type is used for the 71256SA15YG?
The 71256SA15YG is supplied in a 28-pin 300-mil Plastic SOJ (PJG28) package. This gull-wing surface-mount variant supports standard reflow profiles and is mechanically and electrically identical to the PDIP and TSOP variants in the same speed grade - enabling footprint reuse across form factors where board space or assembly method differs.
How does the 71256SA15YG handle power management during idle periods?
The 71256SA15YG supports two low-power standby modes: ISB (40 mA max) when CS is pulled above VIH (TTL threshold), and ISB1 (15 mA max) when CS exceeds VHC (CMOS threshold). This dual-threshold design allows system firmware to dynamically select deeper sleep states based on host logic voltage levels - extending battery life in portable instrumentation without hardware modification.
Is the 71256SA15YG RoHS-compliant and lead-free?
Yes, the 71256SA15YG is a green, RoHS-compliant device with lead-free terminations and halogen-free molding compound. This compliance is confirmed in Renesas' ordering information and aligns with JEDEC J-STD-609A Class 1 marking. No exemptions apply, and the part meets EU Directive 2011/65/EU requirements for hazardous substance restriction.
71256SA15YG 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:
- 15ns
- Access Time:
- 15 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
71256SA15YG FAQ
1.How can I place an order for 71256SA15YG through Aetrix?
Please submit a Request for Quotation (RFQ) for 71256SA15YG 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 71256SA15YG reliable?
The price and inventory of 71256SA15YG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71256SA15YG is usually 5 days.
3.What payment methods are accepted for 71256SA15YG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71256SA15YG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71256SA15YG?
71256SA15YG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71256SA15YG 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 71256SA15YG?
For technical support, including 71256SA15YG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71256SA15YG requirements.
6.How does Aetrix verify that 71256SA15YG is sourced from the original manufacturer or authorized distributors?
All 71256SA15YG 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 71256SA15YG meets industry standards.
7.What is the process for return or replacement of 71256SA15YG?
All 71256SA15YG units undergo pre-shipment inspection (PSI). If there is an issue with 71256SA15YG, 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 71256SA15YG part is unused and in its original packaging.
Return procedure for 71256SA15YG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71256SA15YG Tags
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