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Renesas 71256SA20TPGI
- Part No.:
- 71256SA20TPGI
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-DIP (0.300", 7.62mm)
- Datasheet:
-
71256SA20TPGI.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28DIP
- Quantity:
- Payment:
- Shipping:
Inventory:2,992
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Product details
Overview
71256SA20TPGI from Renesas Electronics is a 32K × 8-bit (262,144-bit) high-speed CMOS static RAM with industrial temperature range (–40°C to +85°C), 20 ns access time, TTL-compatible I/O, single 5 V supply operation, and 28-pin 300-mil plastic DIP package - used in legacy industrial control systems requiring non-refreshed, low-latency memory for real-time data buffering.
For engineers reviewing the 71256SA20TPGI datasheet, 71256SA20TPGI pinout, 71256SA20TPGI application, or 71256SA20TPGI equivalent, key selection criteria include industrial-grade reliability, 20 ns read/write cycle timing, chip select + output enable dual-control architecture, standby current of 40 mA (TTL-level) or 15 mA (CMOS-level), and compatibility with legacy 5 V microcontroller bus interfaces.
Technical Context
The 71256SA20TPGI implements fully static asynchronous circuitry - no clocks or refresh required - enabling deterministic timing in deterministic real-time systems. Its address access time (tAA) and read cycle time (tRC) are both guaranteed at ≤20 ns across the full industrial temperature range, with output enable propagation delay (tOE) ≤10 ns.
It features dual standby modes: ISB (TTL-level CS deassertion) draws 40 mA max, while ISB1 (CMOS-level CS deassertion) reduces current to 15 mA. All inputs and outputs meet TTL voltage thresholds (VIH ≥2.2 V, VIL ≤0.8 V), ensuring direct interfacing with 5 V logic families without level translation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144-bit total); supports byte-wide parallel data transfers without multiplexing. |
| Access Time (tAA) | ≤20 ns - ensures sub-50 MHz bus interface compatibility with legacy 8/16-bit microcontrollers. |
| Read Cycle Time (tRC) | ≤20 ns - enables consecutive read operations at up to 50 MHz sustained rate. |
| Supply Voltage | 4.5 V to 5.5 V - operates reliably across standard 5 V ±10% power rails common in industrial backplanes. |
| Operating Temperature | –40°C to +85°C - qualified for deployment in uncontrolled industrial enclosures and outdoor equipment. |
| Standby Current (ISB1) | 15 mA max - minimizes power during idle states in battery-backed or energy-constrained systems. |
| I/O Compatibility | TTL-compatible inputs/outputs - eliminates need for external bus transceivers when interfacing with 5 V MCUs or FPGAs. |
Pinout & Package
71256SA20TPGI is housed in a 28-pin 300-mil plastic DIP (PTG28) package with through-hole mounting and 0.3-inch body width - compatible with legacy PCB footprints and wave-soldering processes.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus supporting full 32K-word addressing; no internal latching - requires stable address during CS low. |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit TTL-compatible data path; high-impedance when CS or OE is inactive - enables shared bus topology. |
| CS | Chip Select | Active-low enable; controls device selection and power state - deassertion triggers ISB or ISB1 standby mode. |
| OE | Output Enable | Active-low control for output drivers only; allows read operations while CS remains asserted - enables memory read during write cycles on shared buses. |
| WE | Write Enable | Active-low write strobe; initiates write when CS is low - defines write timing window with tWP ≥15 ns minimum pulse width. |
| VCC, GND | Power Supply | Single 5 V supply with dedicated ground pin; decoupling recommended within 10 mm of pins 1 and 28 per layout guidelines. |
Key Features
| Feature | Design Value |
|---|---|
| Fully static operation | No clock, no refresh required - simplifies system design and eliminates refresh overhead in real-time firmware. |
| Dual standby modes | ISB (40 mA) and ISB1 (15 mA) allow trade-off between fast wake-up latency and ultra-low quiescent power. |
| TTL-compatible I/O | Direct interface with 5 V microcontrollers, CPLDs, and legacy peripherals without level-shifting components. |
| Industrial temperature grade | Validated operation from –40°C to +85°C - suitable for factory automation, transportation, and energy infrastructure. |
| 28-pin DIP package | Drop-in replacement for legacy SRAMs in existing through-hole designs - supports manual rework and prototyping. |
Applications
| Industrial PLC Data Buffering | Legacy Medical Instrument Memory |
|---|---|
|
Use Scenario: Storing real-time sensor samples and control setpoints in programmable logic controllers with deterministic scan cycles. IC Role / Device Role / Timing Role: Non-volatile buffer memory holding intermediate process values between scan intervals - accessed synchronously via 5 V CPU bus. Use Value: 20 ns access time ensures zero wait-state operation with 80C188 or similar industrial CPUs, maintaining cycle consistency under thermal stress. |
Use Scenario: Holding calibration tables and waveform buffers in FDA-cleared diagnostic devices with long field lifecycles. IC Role / Device Role / Timing Role: Static RAM providing glitch-free, refresh-free storage for critical runtime parameters - powered from isolated 5 V rail. Use Value: Industrial temperature rating and 15 mA ISB1 current support extended operation in sealed enclosures without active cooling. |
| Avionics Test Equipment Cache | Railway Signaling Controller Memory |
|
Use Scenario: Capturing transient analog-to-digital conversion results during aircraft subsystem functional tests. IC Role / Device Role / Timing Role: High-reliability scratchpad memory interfaced to FPGA-based acquisition logic - accessed via parallel 8-bit bus. Use Value: TTL compatibility and 20 ns timing guarantee deterministic capture window alignment without timing closure risk. |
Use Scenario: Storing interlocking logic state variables in EN 5012x-compliant signaling cabinets operating in outdoor substations. IC Role / Device Role / Timing Role: Fail-safe volatile memory retaining operational context during brief AC brownouts - backed by capacitor hold-up. Use Value: 28-pin DIP package enables field-replaceability and long-term component availability per railway obsolescence management policies. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar static RAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY62256ELL-70SNXI | 32K × 8-bit, 70 ns access, SOIC-28, industrial temp - slower but lower power (ISB = 1 µA). | Suitable for low-speed, ultra-low-power monitoring nodes where timing margin >50 ns exists. | Select when power budget dominates over speed and SOIC footprint is acceptable. |
| AS6C4008-20ZIN | 512K × 8-bit, 20 ns access, TSOP-32 - higher density, different pinout, no DIP option. | Applicable in space-constrained upgrades where board redesign is feasible and capacity expansion needed. | Select only if PCB can accommodate 32-pin TSOP and address/data bus width supports 512K addressing. |
Compared with CY62256ELL-70SNXI and AS6C4008-20ZIN, the 71256SA20TPGI uniquely combines 20 ns speed, industrial temperature rating, 28-pin DIP packaging, and TTL compatibility - making it irreplaceable in legacy 5 V systems requiring drop-in SRAM upgrades without layout changes.
Availability
71256SA20TPGI is available at Aetrix Electronics and suitable for industrial PLCs, legacy medical instruments, avionics test gear, and railway signaling controllers requiring stable component supply across extended product lifecycles.
Supply support for 71256SA20TPGI 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 71256SA20TPGI belongs to Renesas' legacy high-speed CMOS SRAM product line - designed specifically for industrial and aerospace applications demanding reliability, deterministic timing, and long-term availability in through-hole packages.
FAQ
What is the maximum operating frequency supported by the 71256SA20TPGI?
The 71256SA20TPGI does not operate on a clock signal - it is a fully static asynchronous SRAM. Its 20 ns read cycle time (tRC) supports effective bus throughput up to 50 MHz in burst-read scenarios. System-level timing depends on controller setup/hold margins, but the 71256SA20TPGI itself imposes no clock requirement or frequency limit beyond its specified AC parameters.
Does the 71256SA20TPGI require external refresh circuitry?
No - the 71256SA20TPGI uses fully static CMOS memory cells and requires no refresh cycles. This eliminates refresh-related timing constraints, bus contention, or firmware overhead, making it ideal for deterministic real-time systems where predictability is critical. The 71256SA20TPGI retains data indefinitely as long as VCC is maintained within specification.
Can the 71256SA20TPGI be used with 3.3 V microcontrollers?
No - the 71256SA20TPGI is strictly a 5 V device with TTL-compatible I/O thresholds (VIH ≥2.2 V, VIL ≤0.8 V). It is not 3.3 V tolerant and must be operated from a 4.5–5.5 V supply. Interfacing with 3.3 V controllers requires level-shifting circuitry; direct connection risks damage or unreliable operation. The 71256SA20TPGI is intended for legacy 5 V system architectures.
What is the difference between ISB and ISB1 standby current in the 71256SA20TPGI?
ISB (40 mA max) activates when CS rises above VIH (≥2.2 V), placing the device in TTL-level standby. ISB1 (15 mA max) activates when CS rises above VHC (VCC – 0.2 V), entering deeper CMOS-level standby. ISB1 delivers lower power but requires stricter input voltage control - both modes retain full data integrity and support instant wake-up upon CS assertion. The 71256SA20TPGI datasheet specifies both values under industrial conditions.
Is the 71256SA20TPGI RoHS compliant and lead-free?
Yes - the 71256SA20TPGI is a green part per Renesas' ordering information, meaning it complies with RoHS Directive 2011/65/EU and is lead-free. The "G" suffix in the package code (e.g., TPG → TPG, with "G" indicating green) confirms compliance. No leaded variants are offered for this speed/package/temp combination, and all units shipped by Aetrix Electronics meet current environmental regulations.
71256SA20TPGI 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:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 28-PDIP
71256SA20TPGI FAQ
1.How can I place an order for 71256SA20TPGI through Aetrix?
Please submit a Request for Quotation (RFQ) for 71256SA20TPGI 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 71256SA20TPGI reliable?
The price and inventory of 71256SA20TPGI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71256SA20TPGI is usually 5 days.
3.What payment methods are accepted for 71256SA20TPGI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71256SA20TPGI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71256SA20TPGI?
71256SA20TPGI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71256SA20TPGI 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 71256SA20TPGI?
For technical support, including 71256SA20TPGI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71256SA20TPGI requirements.
6.How does Aetrix verify that 71256SA20TPGI is sourced from the original manufacturer or authorized distributors?
All 71256SA20TPGI 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 71256SA20TPGI meets industry standards.
7.What is the process for return or replacement of 71256SA20TPGI?
All 71256SA20TPGI units undergo pre-shipment inspection (PSI). If there is an issue with 71256SA20TPGI, 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 71256SA20TPGI part is unused and in its original packaging.
Return procedure for 71256SA20TPGI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71256SA20TPGI Tags
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M24C02-WMN6TP
STMicroelectronics
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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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