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Renesas 71256SA20TPG
- Part No.:
- 71256SA20TPG
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-DIP (0.300", 7.62mm)
- Datasheet:
-
71256SA20TPG.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,165
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Product details
Overview
71256SA20TPG from Renesas Electronics is a 32K × 8-bit (262,144-bit) high-speed CMOS static RAM with 20 ns access time, TTL-compatible I/O, single 5 V supply operation, and industrial-grade temperature 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, industrial PLCs, and legacy instrumentation requiring deterministic asynchronous memory access.
For engineers reviewing the 71256SA20TPG datasheet, 71256SA20TPG pinout, 71256SA20TPG application, or 71256SA20TPG equivalent, key selection criteria include verified 20 ns read/write cycle timing, TSOP/SOJ/PDIP package compatibility, industrial temperature qualification, and direct replacement feasibility for legacy IDT71256SA-family designs without timing or interface redesign.
Technical Context
The 71256SA20TPG implements fully static asynchronous logic with no clocks or refresh required. Its address decoding, I/O control, and output enable circuitry are optimized for sub-20 ns access under commercial and industrial conditions, with guaranteed tAA ≤ 20 ns and tRC = 20 ns at VCC = 5.0 V ± 10%.
It supports two distinct standby power states: ISB (TTL-level CS deassertion, 40 mA max) and ISB1 (CMOS-level CS deassertion, 15 mA max), enabling dynamic power management in systems with variable activity patterns and strict quiescent current budgets.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144-bit total); enables byte-wide data transfers without external multiplexing |
| Access Time (tAA) | 20 ns max; ensures deterministic read latency for real-time control loops and interrupt service routines |
| Supply Voltage | 4.5 V to 5.5 V; compatible with standard 5 V TTL/CMOS system rails without regulation overhead |
| Operating Temperature | –40°C to +85°C; qualified for industrial environments including factory automation and outdoor telemetry |
| Standby Current (ISB1) | 15 mA max at VCC = 5.5 V; reduces idle power in battery-backed or energy-sensitive applications |
| I/O Compatibility | TTL input thresholds (VIH ≥ 2.2 V, VIL ≤ 0.8 V) and output drive (VOH ≥ 2.4 V, VOL ≤ 0.4 V); interoperable with legacy 5 V microcontrollers and FPGAs |
| Package | 28-pin 300-mil Plastic DIP (PTG28); through-hole mounting for prototyping, repair, and high-reliability board assembly |
Pinout & Package
71256SA20TPG is housed in a 28-pin 300-mil Plastic Dual In-line Package (PDIP), designated PTG28 per Renesas ordering nomenclature. This through-hole package supports manual soldering, socket-based testing, and long-term mechanical stability in vibration-prone industrial enclosures.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus supporting full 32K-word addressing; synchronous with CS/OE for stable decode |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit TTL-compatible data path; direction controlled by WE and CS; high-impedance when deselected or OE disabled |
| CS | Chip Select | Active-low enable for device selection; controls ISB/ISB1 standby modes and power-up timing (tPU) |
| WE | Write Enable | Active-low write strobe; defines write cycle boundaries (tWC, tWP, tDW) and disables outputs during write |
| OE | Output Enable | Active-low output gate; enables read data (tOE ≤ 10 ns) while preserving address/data bus isolation |
| VCC | Power Supply | +5 V supply pin; decoupling required within 1 cm for stable 20 ns timing margin |
| GND | Ground Reference | Signal and power return; must be low-inductance connection to minimize noise on I/O and address lines |
Key Features
| Feature | Design Value |
|---|---|
| Asynchronous Static Operation | No clock or refresh circuitry required - simplifies timing design and eliminates hidden refresh latency in real-time systems |
| Dual Standby Power Modes | ISB1 (15 mA) enables ultra-low-power hold state when CS driven above VHC; ISB (40 mA) supports faster wake-up from TTL-level deselect |
| Guaranteed 20 ns Timing | tAA, tRC, tWC all specified at 20 ns max across full industrial temperature range - eliminates derating uncertainty in field-deployed hardware |
| TTL-Compatible I/O | Direct interface with legacy 8051, Z80, and FPGA I/O banks without level-shifting components or external buffers |
| Green Compliant Packaging | Meets RoHS Directive 2011/65/EU; lead-free terminations and halogen-free molding compound for environmentally regulated deployments |
Applications
| Industrial PLC Memory Buffer | Legacy Microcontroller Data RAM |
|---|---|
Use Scenario: Stores I/O scan data, ladder logic variables, and communication buffers in DIN-rail mounted programmable logic controllers operating in factory environments with wide ambient temperature swings. IC Role / Device Role / Timing Role: Asynchronous SRAM providing zero-wait-state data storage for 8-bit/16-bit MCUs; accessed via dedicated address/data bus with CS/OE-controlled page reads. Use Value: 20 ns access time ensures deterministic response to fast I/O interrupts; industrial temp rating (-40°C to +85°C) prevents data corruption during unconditioned cabinet operation. | Use Scenario: Serves as external data RAM for vintage 8-bit microcontrollers (e.g., Intel 8031, Motorola 6809) in medical analyzers and test equipment where firmware upgrades are infrequent but reliability is critical. IC Role / Device Role / Timing Role: Byte-wide static RAM mapped into the MCU's external memory space; enabled by fixed CS decode logic and timed using WE/OE handshaking. Use Value: TTL-compatible signaling eliminates level translators; PDIP package allows field replacement and socket-based diagnostics in aging equipment fleets. |
| Avionics Data Logger Cache | Test Equipment Pattern Memory |
Use Scenario: Buffers sensor telemetry streams in airborne data acquisition units subject to thermal cycling, shock, and EMI - deployed in certified avionics subsystems with long lifecycle requirements. IC Role / Device Role / Timing Role: High-reliability SRAM holding pre-triggered flight data snapshots; accessed via deterministic read cycles synchronized to ADC sampling clocks. Use Value: Fully static architecture avoids refresh-induced data loss during power transients; ISB1 standby mode extends battery life during dormant logging intervals. | Use Scenario: Stores digital stimulus/response patterns in automated test equipment (ATE) for semiconductor wafer probing, where pattern depth exceeds on-chip memory capacity. IC Role / Device Role / Timing Role: External pattern RAM interfaced to high-speed pattern generator ASICs; accessed in burst mode with precise tOH and tDH timing control. Use Value: 20 ns tOH (3 ns min) guarantees clean data hold after address changes; bidirectional I/O supports both upload and verification phases without bus contention. |
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, SOIC-28 package | Higher density but slower speed and incompatible voltage; requires level translation in 5 V systems | Select only if migrating to 3.3 V architecture and needing >256K capacity; not drop-in for 71256SA20TPG |
| AS6C4008-20ZIN | 512K × 8-bit, 20 ns access, 5 V tolerant, SOP-28 package | Same speed and voltage, but larger density and surface-mount only; pinout differs significantly | Consider for new designs targeting higher memory depth; requires PCB redesign due to different pin mapping and package |
Compared with CY62128EV30LL-45ZSXIT and AS6C4008-20ZIN, the 71256SA20TPG offers verified 5 V TTL compatibility, PDIP packaging for serviceability, and exact 32K × 8 organization - making it uniquely suitable for maintaining legacy 5 V systems without timing or layout changes.
Availability
71256SA20TPG is available at Aetrix Electronics and suitable for industrial PLCs, legacy microcontroller systems, avionics data loggers, and automated test equipment requiring stable component supply, long-lifecycle support, and through-hole assembly compatibility.
Supply support for 71256SA20TPG 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, infrastructure, and IoT applications.
The 71256SA20TPG belongs to Renesas' legacy high-speed CMOS SRAM product line, designed specifically for backward-compatible replacement of IDT-era static RAMs in mission-critical industrial and aerospace systems requiring proven reliability and long-term availability.
FAQ
What is the maximum operating temperature range for the 71256SA20TPG?
The 71256SA20TPG 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 access time (tAA ≤ 20 ns), standby current (ISB1 ≤ 15 mA), and I/O voltage thresholds. The part is not qualified for extended temperature ranges beyond this limit.
Does the 71256SA20TPG require a clock signal or refresh circuitry?
No, the 71256SA20TPG uses fully static CMOS design and requires no clock input or periodic refresh cycles. Its internal memory array retains data indefinitely as long as VCC is applied and CS remains asserted during active use. This eliminates timing complexity and hidden failure modes associated with dynamic RAM refresh management.
What package type does the 71256SA20TPG use, and is it RoHS compliant?
The 71256SA20TPG uses a 28-pin 300-mil Plastic Dual In-line Package (PDIP), identified as PTG28 in Renesas documentation. It is RoHS-compliant and classified as a "Green" part per Renesas ordering information - meaning it contains no lead, mercury, cadmium, hexavalent chromium, PBB, or PBDE, and uses halogen-free molding compound.
How does the Output Enable (OE) pin function in the 71256SA20TPG?
In the 71256SA20TPG, the OE pin is an active-low control that gates the output drivers independently of Chip Select (CS). When OE is low and CS is low, data appears on I/O0–I/O7 within tOE ≤ 10 ns. When OE is high, outputs enter high-impedance state even if CS is active - enabling shared bus arbitration without requiring CS toggling during multi-device transfers.
Can the 71256SA20TPG be used as a direct replacement for older IDT71256SA-20 variants?
Yes, the 71256SA20TPG is a Renesas-branded continuation of the original IDT71256SA-20 product line, with identical pinout, timing specifications, electrical characteristics, and functional behavior. Renesas explicitly rebranded and maintained this family post-acquisition, and the 71256SA20TPG is documented as functionally and mechanically equivalent to IDT71256SA-20TPG in all operational modes.
71256SA20TPG 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:
- 20ns
- Access Time:
- 20 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
71256SA20TPG FAQ
1.How can I place an order for 71256SA20TPG through Aetrix?
Please submit a Request for Quotation (RFQ) for 71256SA20TPG 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 71256SA20TPG reliable?
The price and inventory of 71256SA20TPG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71256SA20TPG is usually 5 days.
3.What payment methods are accepted for 71256SA20TPG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71256SA20TPG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71256SA20TPG?
71256SA20TPG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71256SA20TPG 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 71256SA20TPG?
For technical support, including 71256SA20TPG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71256SA20TPG requirements.
6.How does Aetrix verify that 71256SA20TPG is sourced from the original manufacturer or authorized distributors?
All 71256SA20TPG 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 71256SA20TPG meets industry standards.
7.What is the process for return or replacement of 71256SA20TPG?
All 71256SA20TPG units undergo pre-shipment inspection (PSI). If there is an issue with 71256SA20TPG, 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 71256SA20TPG part is unused and in its original packaging.
Return procedure for 71256SA20TPG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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