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Renesas 71256SA20PZGI
- Part No.:
- 71256SA20PZGI
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-TSSOP (0.465", 11.80mm Width)
- Datasheet:
-
71256SA20PZGI.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28TSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,144
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Product details
Overview
71256SA20PZGI from Renesas Electronics is a 32K × 8-bit (256 Kbit) high-speed CMOS static RAM with industrial temperature support (–40°C to +85°C), 20 ns read/write cycle time, TTL-compatible I/O, single 5 V supply operation, and TSOP-28 packaging. It serves as nonvolatile-cache buffer or main memory in legacy industrial controllers requiring deterministic access without refresh.
For engineers reviewing the 71256SA20PZGI datasheet, 71256SA20PZGI pinout, 71256SA20PZGI application, or 71256SA20PZGI equivalent, key selection criteria include guaranteed 20 ns access under industrial thermal stress, standby current of 40 mA at max VCC, CMOS-level standby mode (ISB1 = 15 mA), bidirectional TTL I/O drive capability, and TSOP-28 footprint compatibility with legacy board layouts.
Technical Context
The 71256SA20PZGI implements fully static asynchronous architecture-no clocks or refresh required-with independent chip select (CS) and output enable (OE) control enabling flexible bus arbitration. Its address-access timing (tAA ≤ 20 ns) and chip-select access (tACS ≤ 20 ns) are matched to ensure consistent latency across all valid address transitions.
It supports two standby modes: TTL-level (ISB = 40 mA) when CS > VIH, and low-power CMOS-level (ISB1 = 15 mA) when CS > VHC and all inputs held valid, enabling dynamic power scaling in battery-backed or thermally constrained systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144 bits), byte-wide parallel interface |
| Access Time (tAA) | ≤20 ns - guarantees data validity within 20 ns of stable address and CS assertion |
| Read Cycle Time (tRC) | 20 ns - minimum interval between successive read operations |
| Supply Voltage | 4.5 V to 5.5 V - compatible with standard 5 V TTL logic rails |
| Operating Temperature | –40°C to +85°C - qualified for industrial-grade embedded control environments |
| Standby Current (ISB1) | 15 mA max at VCC = 5.5 V - enables ultra-low-power hold state when inputs meet CMOS threshold |
| 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) |
Pinout & Package
71256SA20PZGI is housed in a 28-pin TSOP Type I (PZG28) package, 8.1 mm × 13.4 mm body, 0.5 mm lead pitch, JEDEC MO-153 compliant. Pin 1 marked via notch or bevel; top-side marking includes "71256SA20PZGI" and date code.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus (32K = 2¹⁵); latched on CS/WE edges; no internal multiplexing |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit TTL-compatible data path; high-impedance when CS high or OE high |
| CS | Chip Select | Active-low enable; controls ISB/ISB1 standby entry and tACS timing |
| OE | Output Enable | Active-low; enables output drivers independently of CS; tOE ≤ 10 ns |
| WE | Write Enable | Active-low; initiates write cycle; tWP ≥ 15 ns minimum pulse width |
| VCC | Power Supply | +5 V ±10 %; decoupling required per JEDEC guidelines for 20 ns operation |
| GND | Ground Reference | Signal and power return; separate ground plane recommended for noise immunity |
Key Features
| Feature | Design Value |
|---|---|
| Industrial temperature grade | –40°C to +85°C operation validated per Renesas qualification standards, not derated |
| Dual standby modes | ISB = 40 mA (TTL-level CS deassertion) and ISB1 = 15 mA (CMOS-level CS deassertion) for adaptive power management |
| Asynchronous static core | No clock, no refresh, no wait states - deterministic timing under all operating conditions |
| TTL-compatible I/O | Direct interfacing with 74LS/74ALS logic families without level-shifting or buffering |
| TSOP-28 footprint | Surface-mount package supporting automated assembly and higher board density vs. DIP/SOJ alternatives |
Applications
| Industrial PLC Memory Buffer | Legacy Medical Device Data Cache |
|---|---|
|
Use Scenario: Real-time I/O scanning in programmable logic controllers where deterministic memory access prevents scan-time jitter. IC Role / Device Role / Timing Role: Primary working memory for ladder logic execution engine; accessed synchronously with CPU bus cycles. Use Value: 20 ns tAA ensures sub-microsecond response to status changes, meeting IEC 61131-3 cycle-time requirements for safety-rated controllers. |
Use Scenario: Temporary storage of waveform samples in portable ECG monitors during analog-to-digital conversion bursts. IC Role / Device Role / Timing Role: High-speed scratchpad memory holding 32K samples before DMA transfer to microcontroller SRAM. Use Value: Bidirectional TTL I/O allows direct connection to ADC output bus, eliminating glue logic and reducing BOM count. |
| Avionics Test Equipment FIFO | Ruggedized Network Node Packet Buffer |
|
Use Scenario: First-in-first-out buffering of MIL-STD-1553B bus transaction logs in ground-support test rigs. IC Role / Device Role / Timing Role: Static RAM configured as circular buffer; CS toggled per packet to minimize power during idle intervals. Use Value: ISB1 = 15 mA standby current extends battery life in portable avionics testers without compromising wake-up latency. |
Use Scenario: Frame buffering in DIN-rail-mounted Ethernet-to-serial gateways deployed in factory-floor environments. IC Role / Device Role / Timing Role: Intermediary storage between PHY MAC layer and ARM-based protocol stack; accessed via GPIO-banged parallel bus. Use Value: Industrial temp rating and TSOP packaging withstand vibration and thermal cycling in uncontrolled enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar static RAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY62256LL-70SXI | Same 32K × 8 organization, 70 ns speed grade, SOIC-28 package, –40°C to +85°C | Slower access invalidates use in <25 ns timing-critical control loops | Select only if system timing budget permits ≥70 ns latency and SOIC footprint is preferred over TSOP |
| AS6C4008-20TIN | 32K × 8, 20 ns, TSOP-28, –40°C to +85°C, but 3.3 V only (not 5 V tolerant) | Requires level-shifting or voltage translation when interfacing with 5 V legacy buses | Choose only when migrating to 3.3 V systems; incompatible with direct 5 V TTL replacement |
Compared with CY62256LL-70SXI and AS6C4008-20TIN, the 71256SA20PZGI uniquely delivers 20 ns performance in a 5 V TTL-compatible TSOP-28 package qualified for industrial temperatures-enabling drop-in replacement in aging 5 V controller designs without layout or voltage rail changes.
Availability
71256SA20PZGI is available at Aetrix Electronics and suitable for industrial PLCs, legacy medical instrumentation, avionics test equipment, and ruggedized network nodes requiring stable component supply across extended product lifecycles.
Supply support for 71256SA20PZGI 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 IDT71256SA family-now rebranded under Renesas-was designed specifically for high-reliability, pin-compatible replacement of legacy 256 Kbit SRAMs in industrial control and instrumentation systems requiring long-term availability and extended temperature support.
FAQ
What is the maximum operating frequency supported by the 71256SA20PZGI?
The 71256SA20PZGI does not operate on a clock signal-it is an asynchronous static RAM. Its maximum effective throughput is determined by its 20 ns read/write cycle time (tRC), enabling up to 50 million operations per second in ideal bus conditions. Timing is governed solely by address stability, CS/OE/WE edge alignment, and load capacitance-not by an external clock.
Does the 71256SA20PZGI require refresh circuitry or periodic maintenance?
No. The 71256SA20PZGI uses fully static CMOS memory cells and requires no refresh cycles, clocks, or hidden maintenance operations. Data retention is indefinite as long as VCC remains within specification and temperature stays within –40°C to +85°C. This eliminates timing overhead and simplifies controller firmware design.
Can the 71256SA20PZGI be used in place of a 71256SA15PZGI on the same PCB?
Yes-both share identical TSOP-28 (PZG28) pinout, voltage, and interface signaling. The 71256SA20PZGI is functionally backward-compatible with the 15 ns variant, though it exhibits longer access and cycle times (20 ns vs. 15 ns). System timing margins must be re-verified, but no PCB modification is needed for substitution.
What is the difference between ISB and ISB1 standby current in the 71256SA20PZGI?
ISB (40 mA max) activates when CS rises above VIH (≥2.2 V), providing basic deselection. ISB1 (15 mA max) engages only when CS exceeds VHC (VCC – 0.2 V) *and* all other inputs are held cleanly at valid TTL high/low levels-enabling deeper power savings in systems with clean control logic.
Is the 71256SA20PZGI RoHS-compliant and halogen-free?
Yes. Per Renesas' 2020 datasheet revision, the 71256SA20PZGI is a "Green" part-compliant with RoHS Directive 2011/65/EU and halogen-free per IEC 61249-2-21. The "G" suffix in the ordering code confirms this compliance, and material declarations are available through Renesas' official product page.
71256SA20PZGI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 28-TSSOP (0.465", 11.80mm 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:
- 20ns
- Access Time:
- 20 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-TSOP
71256SA20PZGI FAQ
1.How can I place an order for 71256SA20PZGI through Aetrix?
Please submit a Request for Quotation (RFQ) for 71256SA20PZGI 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 71256SA20PZGI reliable?
The price and inventory of 71256SA20PZGI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71256SA20PZGI is usually 5 days.
3.What payment methods are accepted for 71256SA20PZGI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71256SA20PZGI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71256SA20PZGI?
71256SA20PZGI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71256SA20PZGI 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 71256SA20PZGI?
For technical support, including 71256SA20PZGI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71256SA20PZGI requirements.
6.How does Aetrix verify that 71256SA20PZGI is sourced from the original manufacturer or authorized distributors?
All 71256SA20PZGI 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 71256SA20PZGI meets industry standards.
7.What is the process for return or replacement of 71256SA20PZGI?
All 71256SA20PZGI units undergo pre-shipment inspection (PSI). If there is an issue with 71256SA20PZGI, 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 71256SA20PZGI part is unused and in its original packaging.
Return procedure for 71256SA20PZGI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71256SA20PZGI Tags
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