My Inquiry
My Account
Renesas 71256SA25TPGI
- Part No.:
- 71256SA25TPGI
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-DIP (0.300", 7.62mm)
- Datasheet:
-
71256SA25TPGI.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28DIP
- Quantity:
- Payment:
- Shipping:
Inventory:2,959
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
71256SA25TPGI from Renesas Electronics is a 32K × 8 (256 Kbit) high-speed CMOS static RAM with industrial temperature support (–40°C to +85°C), 25 ns read/write cycle time, TTL-compatible I/O, and single 5 V supply operation. It serves as a non-refreshing, asynchronous memory buffer in embedded controllers, industrial PLCs, and legacy instrumentation requiring deterministic access timing.
For engineers reviewing the 71256SA25TPGI datasheet, 71256SA25TPGI pinout, 71256SA25TPGI application, or 71256SA25TPGI equivalent, this device delivers verified 25 ns access under industrial conditions, low-standby current (40 mA ISB), and dual chip select/output enable control for flexible bus interfacing in space-constrained DIP-based designs.
Technical Context
The 71256SA25TPGI implements fully static asynchronous logic with no clocks or refresh required. Its address decoder drives a 262,144-bit memory array using high-reliability CMOS process technology, enabling stable operation across voltage (4.5–5.5 V) and temperature extremes without timing drift.
All inputs and outputs are TTL-compatible with defined VIH/VIL thresholds and bidirectional I/O drivers. Standby power management is achieved via two distinct low-power modes: ISB (TTL-level CS deassertion) and ISB1 (CMOS-level CS deassertion), delivering 40 mA and 15 mA supply current respectively at VCC max.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (256 Kbit); supports byte-wide data bus without external multiplexing |
| Access Time (tAA) | 25 ns max; guarantees valid data output within 25 ns of address/CS assertion at industrial temp |
| Read Cycle Time (tRC) | 25 ns max; enables consecutive reads at up to 40 MHz sustained rate |
| Supply Voltage | 4.5 V to 5.5 V; compatible with standard 5 V TTL/CMOS logic rails without regulation |
| Operating Temperature | –40°C to +85°C; qualified for industrial environments including factory automation and motor control |
| Standby Current (ISB) | 40 mA max at VCC = 5.5 V; reduces system power during idle without sacrificing wake-up latency |
| 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 at 4 mA/8 mA) |
Pinout & Package
71256SA25TPGI is packaged in a 28-pin 300-mil plastic DIP (PTG28), with through-hole mounting and 0.3-inch body width suitable for legacy PCB layouts and prototyping.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus supporting full 32K word selection; no internal latching |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit TTL-compatible data path; direction controlled by WE and OE states |
| CS | Chip Select | Active-low enable for device selection; controls ISB/ISB1 standby entry and ICC activation |
| OE | Output Enable | Active-low control for output drivers; allows read data gating independent of CS |
| WE | Write Enable | Active-low signal initiating write cycle; determines timing reference for tDW, tWP, and tDH |
| 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 |
|---|---|
| Industrial temperature range | Rated for –40°C to +85°C operation with full AC/DC specification compliance |
| Dual standby power modes | ISB (40 mA) and ISB1 (15 mA) allow optimized power trade-off based on CS logic level |
| Asynchronous static architecture | No clocks, no refresh cycles, no wait states - simplifies timing-critical microcontroller interfaces |
| TTL-compatible I/O | Direct interface to 5 V microcontrollers, FPGAs, and ASICs without level-shifting circuitry |
| Green packaging option | Lead-free, RoHS-compliant construction with halogen-free materials per ordering code suffix |
Applications
| Industrial PLC Memory Buffer | Legacy Test Equipment 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: Asynchronous SRAM providing zero-wait-state storage for register-mapped I/O buffers and status tables. Use Value: 25 ns tAA ensures consistent 40 MHz burst reads across full temperature range, eliminating timing margin uncertainty in safety-critical cycles. |
Use Scenario: High-fidelity waveform capture in benchtop oscilloscopes and logic analyzers requiring fast, reliable local memory. IC Role / Device Role / Timing Role: Byte-wide data buffer staging sampled signals before serial transfer to host processor. Use Value: Bidirectional I/O and separate OE/WE control enable simultaneous acquisition and readout without bus contention or added glue logic. |
| Motor Drive Controller Code Storage | Avionics Maintenance Terminal RAM |
|
Use Scenario: Storing runtime configuration parameters and fault logs in brushless DC motor drives operating in harsh thermal environments. IC Role / Device Role / Timing Role: Non-volatile-supporting volatile memory holding calibration tables and event history with fast write capability. Use Value: 25 ns tWP and tDW guarantee reliable parameter updates even during transient voltage dips common in 24 V industrial power rails. |
Use Scenario: Onboard diagnostics and configuration storage in portable avionics test sets used across hangar-to-flight-line temperature swings. IC Role / Device Role / Timing Role: Industrial-grade SRAM retaining operational state during cold-start and thermal cycling. Use Value: Qualified –40°C to +85°C performance eliminates derating concerns and supports MIL-STD-810G environmental compliance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-speed static RAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY62128EV30LL-45ZSXIT | 128K × 8 organization, 45 ns access, 3.3 V supply only, TSOP-32 package | Higher density but incompatible voltage and pinout; requires board redesign and level translation | Select only when upgrading capacity and migrating to 3.3 V systems with available PCB space for 32-pin TSOP |
| AS6C4008-25ZIN | 512K × 8 organization, 25 ns access, 5 V supply, SOJ-32 package | Double density and same speed, but 32-pin SOJ footprint differs from 28-pin DIP; no direct drop-in replacement | Consider for new designs needing higher memory depth while maintaining 5 V compatibility and industrial temp rating |
Compared with 71256SA25TPGI, CY62128EV30LL-45ZSXIT offers greater density but mandates 3.3 V operation and package change, whereas AS6C4008-25ZIN matches speed and voltage but requires SOJ-32 layout adaptation - neither is pin-compatible, making 71256SA25TPGI uniquely suited for retrofitting 28-pin DIP-based industrial hardware.
Availability
71256SA25TPGI is available at Aetrix Electronics and suitable for industrial PLCs, legacy test equipment, motor drive controllers, and avionics maintenance terminals requiring stable component supply with long-term lifecycle assurance.
Supply support for 71256SA25TPGI 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 is a global semiconductor leader specializing in microcontrollers, analog, power, and memory solutions for automotive, industrial, and infrastructure markets.
The IDT71256SA family - now part of Renesas' legacy memory portfolio - was designed specifically for high-reliability, asynchronous SRAM applications in industrial control and instrumentation where timing predictability and temperature resilience are critical.
FAQ
What is the maximum operating frequency supported by the 71256SA25TPGI?
The 71256SA25TPGI does not operate on a clock but supports a maximum sustained read/write cycle rate of 40 MHz, derived from its 25 ns read cycle time (tRC). This enables deterministic, zero-wait-state interfacing with microcontrollers and FPGAs running at up to 40 MHz bus speeds, provided address and control setup/hold times are met per the datasheet's AC timing table.
Does the 71256SA25TPGI require a refresh circuit or external clock signal?
No, the 71256SA25TPGI uses fully static CMOS design and requires no refresh cycles or clock input. It operates asynchronously - data is accessed solely via address, CS, OE, and WE signals - making it ideal for simple microcontroller buses and real-time systems where clock domain isolation is essential.
Is the 71256SA25TPGI RoHS-compliant and lead-free?
Yes, the 71256SA25TPGI is a green part compliant with RoHS Directive 2011/65/EU and uses lead-free, halogen-free packaging. The "G" suffix in the ordering code (e.g., TPGI → "G") explicitly denotes Renesas' Green standard, confirmed in the June 2020 datasheet revision and ordering information tables.
Can the 71256SA25TPGI be used in place of the 71256SA15TPGI or 71256SA20TPGI on the same PCB?
Yes - all three share identical pinout, package (PTG28 DIP), voltage, and functional interface. The only difference is guaranteed access time (15/20/25 ns), so substituting 71256SA25TPGI into a design originally using faster variants will maintain full electrical and mechanical compatibility, though maximum bus speed must be reduced to match the 25 ns timing.
What is the purpose of the two standby current specifications (ISB and ISB1) for the 71256SA25TPGI?
ISB (40 mA max) activates when CS rises above TTL VIH (≥2.2 V), suitable for systems using standard logic-level deassertion. ISB1 (15 mA max) engages only when CS exceeds CMOS threshold (VCC – 0.2 V), enabling deeper power savings in designs with clean, rail-swing control signals - both modes retain full data retention without loss.
71256SA25TPGI 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:
- 25ns
- Access Time:
- 25 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
71256SA25TPGI FAQ
1.How can I place an order for 71256SA25TPGI through Aetrix?
Please submit a Request for Quotation (RFQ) for 71256SA25TPGI 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 71256SA25TPGI reliable?
The price and inventory of 71256SA25TPGI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71256SA25TPGI is usually 5 days.
3.What payment methods are accepted for 71256SA25TPGI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71256SA25TPGI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71256SA25TPGI?
71256SA25TPGI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71256SA25TPGI 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 71256SA25TPGI?
For technical support, including 71256SA25TPGI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71256SA25TPGI requirements.
6.How does Aetrix verify that 71256SA25TPGI is sourced from the original manufacturer or authorized distributors?
All 71256SA25TPGI 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 71256SA25TPGI meets industry standards.
7.What is the process for return or replacement of 71256SA25TPGI?
All 71256SA25TPGI units undergo pre-shipment inspection (PSI). If there is an issue with 71256SA25TPGI, 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 71256SA25TPGI part is unused and in its original packaging.
Return procedure for 71256SA25TPGI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71256SA25TPGI Tags
-
M24C02-WMN6TP
STMicroelectronics
-
AT24C02C-XHM-T
Microchip Technology
-
AT21CS01-STUM10-T
Microchip Technology
-
AT24C02C-SSHM-T
Microchip Technology
-
24LC01BT-I/OT
Microchip Technology
-
M24C02-FMC6TG
STMicroelectronics
-
AT24CS02-SSHM-T
Microchip Technology
-
93LC46BT-I/OT
Microchip Technology
-
AT24C04C-SSHM-T
Microchip Technology
-
24LC01BT-I/SN
Microchip Technology
-
24AA02UIDT-I/OT
Microchip Technology
-
AT24C08C-STUM-T
Microchip Technology
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
