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Renesas IDT71256SA15TPI
- Part No.:
- IDT71256SA15TPI
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-DIP (0.300", 7.62mm)
- Datasheet:
-
IDT71256SA15TPI.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28DIP
- Quantity:
- Payment:
- Shipping:
Inventory:3,967
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Product details
Overview
IDT71256SA15TPI from Renesas Electronics is a 32K × 8 (256 Kbit) high-speed CMOS static RAM with industrial temperature support (–40°C to +85°C), 15 ns access time, TTL-compatible I/O, and single 5 V supply operation. It serves as a non-refreshing, asynchronous memory buffer in embedded controllers, instrumentation systems, and legacy industrial PLCs requiring deterministic read/write timing.
For engineers reviewing the IDT71256SA15TPI datasheet, IDT71256SA15TPI pinout, IDT71256SA15TPI application, or IDT71256SA15TPI equivalent, key selection criteria include industrial-grade reliability, 28-pin TSOP-28 package compatibility, low standby current (15 mA at CMOS-level deselect), and verified 15 ns cycle time under full temperature range.
Technical Context
The IDT71256SA15TPI implements fully static asynchronous architecture with no clocks or refresh required. Its control logic supports independent chip select (CS) and output enable (OE) for flexible bus arbitration, and bidirectional I/O lines operate with TTL-level thresholds (VIH = 2.2 V min, VIL = 0.8 V max) at 5 V ±10%.
It features dual standby modes: ISB (TTL-level CS high, 40 mA max) and ISB1 (CMOS-level CS high, 15 mA max), enabling power optimization in intermittently active systems. Timing is defined by overlapping CS/WE/OE transitions, with write cycles controlled either by WE (tWP ≥ 10 ns) or CS (tCW ≥ 10 ns), per AC Table 9.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144 bits), fixed parallel interface with no internal addressing multiplexing |
| Access Time (tAA) | 15 ns max - guarantees data valid within 15 ns of address/CS assertion, critical for real-time interrupt handlers |
| Supply Voltage | 4.5 V to 5.5 V - compatible with legacy 5 V TTL/CMOS buses without level-shifting |
| Standby Current (ISB1) | 15 mA max at CMOS-level deselect - enables ultra-low-power sleep mode when CS > VHC |
| Operating Temperature | –40°C to +85°C - qualified for industrial automation, motor drives, and outdoor metering environments |
| I/O Compatibility | TTL input thresholds & output drive (VOH ≥ 2.4 V @ –4 mA, VOL ≤ 0.4 V @ 8 mA) - direct interfacing with 74LS/ALS logic |
| Package | 28-pin TSOP Type I (PZG28), 8.1 mm × 13.4 mm footprint - surface-mount compatible with high-density PCB layouts |
Pinout & Package
Package: 28-pin TSOP Type I (PZG28), 8.1 mm × 13.4 mm body, 0.55 mm pitch, JEDEC MO-153 compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit unidirectional address bus; A0 = LSB, A14 = MSB; no multiplexing required |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit TTL-compatible data path; high-impedance when CS high or OE high during reads/writes |
| CS | Chip Select | Active-low enable; controls device selection and power state (ISB/ISB1 modes) |
| OE | Output Enable | Active-low; gates output drivers independently of CS, enabling shared-bus contention management |
| WE | Write Enable | Active-low; initiates write cycle when CS low; determines timing control mode (WE- or CS-driven) |
| VCC | Power Supply | +5 V supply pin; decoupling required within 10 mm due to 160 mA dynamic ICC peak |
| GND | Ground | Signal and power return; dedicated pin (Pin 16) minimizes ground bounce in high-speed access |
Key Features
| Feature | Design Value |
|---|---|
| Industrial Temperature Range | –40°C to +85°C operation validated across all AC/DC parameters - eliminates derating concerns in factory-floor deployments |
| Dual Standby Power Modes | ISB1 (15 mA) activated via CMOS-level CS high (>VCC–0.2 V), enabling 62.5% lower quiescent power vs. standard ISB (40 mA) |
| TTL-Compatible Interface | Direct connection to legacy microcontrollers (e.g., Intel 80Cxx, Motorola 68K) without external level shifters or pull-ups |
| No Refresh or Clock Required | Fully static design eliminates DRAM-style refresh overhead and timing jitter - simplifies firmware and reduces CPU load |
| Green Compliant Packaging | Lead-free, RoHS-compliant TSOP package (PZG28) with halogen-free molding compound - meets IPC-1752A reporting requirements |
Applications
| Industrial PLC Data Buffer | Legacy Microcontroller Memory Expansion |
|---|---|
|
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 buffer storing process image data between CPU and field I/O modules. Use Value: 15 ns tAA ensures sub-microsecond response to hardware interrupts, maintaining <100 µs PLC scan cycles under full I/O load. |
Use Scenario: External program/data memory expansion for 8-bit/16-bit MCUs (e.g., Z80, 8085, 68000) in retro-computing or medical device upgrades. IC Role / Device Role / Timing Role: Parallel memory mapped into CPU address space using CS/OE decoding logic. Use Value: TTL-compatible I/O and 5 V operation eliminate interface glue logic, reducing BOM count and layout complexity. |
| Automated Test Equipment (ATE) Pattern Memory | Avionics Display Controller Frame Buffer |
|
Use Scenario: Storing test vectors and expected results in high-speed digital pattern generators used in semiconductor wafer testing. IC Role / Device Role / Timing Role: High-reliability, non-volatile-equivalent storage for deterministic waveform generation sequences. Use Value: Industrial temp rating and 15 ns cycle time support stable operation at 66 MHz system clock rates with zero wait states. |
Use Scenario: Frame buffer for monochrome or grayscale cockpit displays in certified avionics systems requiring long-term reliability. IC Role / Device Role / Timing Role: Dual-port accessible memory (via CS/OE sequencing) for simultaneous CPU write and display controller read. Use Value: Low ISB1 current (15 mA) extends battery-backed operation during aircraft power-down sequences without compromising frame integrity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar static RAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY62128EV30LL-45ZSXI | 32K × 8, 45 ns access, 3 V core (with 5 V tolerant I/O), SOIC-28 package | Lower voltage operation but slower speed; unsuitable for 15 ns timing-critical paths | Select only if system operates at ≤22 MHz and requires 3 V supply compatibility |
| AS6C4008-15TIN | 32K × 8, 15 ns access, industrial temp, 28-pin TSOP, but 2.7–3.6 V supply only | Requires level translation for 5 V systems; incompatible with direct TTL bus interfacing | Choose only for new 3.3 V designs where board-level voltage translation is already implemented |
Compared with CY62128EV30LL-45ZSXI and AS6C4008-15TIN, the IDT71256SA15TPI uniquely delivers 15 ns performance at 5 V with TTL compatibility and industrial temperature qualification - making it the sole drop-in replacement for legacy 5 V systems requiring guaranteed sub-20 ns timing.
Availability
IDT71256SA15TPI is available at Aetrix Electronics and suitable for industrial automation, legacy equipment repair, and avionics subsystems requiring stable component supply and long-lifecycle support.
Supply support for IDT71256SA15TPI 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 IDT71256SA15TPI belongs to Renesas' legacy high-speed CMOS SRAM product line, designed specifically for backward-compatible memory upgrades in 5 V industrial control and instrumentation systems.
FAQ
What is the maximum operating frequency supported by the IDT71256SA15TPI?
The IDT71256SA15TPI does not use a clock; its maximum effective throughput is determined by its 15 ns read/write cycle time (tRC), supporting up to 66.7 MHz random-access operation. This assumes full address and control setup/hold compliance per AC Table 9 - no external clock signal is required or used in the IDT71256SA15TPI's fully static architecture.
Does the IDT71256SA15TPI require refresh circuitry or periodic memory maintenance?
No, the IDT71256SA15TPI is a fully static RAM and contains no capacitive storage cells. It retains data indefinitely as long as VCC is applied and CS remains asserted or in standby mode - no refresh cycles, timers, or external support circuitry are needed for the IDT71256SA15TPI to maintain data integrity.
Can the IDT71256SA15TPI be used in a 3.3 V system?
No - the IDT71256SA15TPI is specified only for 4.5 V to 5.5 V operation. Its TTL-compatible inputs require VIH ≥ 2.2 V and VIL ≤ 0.8 V, and its outputs drive VOH ≥ 2.4 V at –4 mA. Using it below 4.5 V risks timing violations and output drive failure; the IDT71256SA15TPI is not 3.3 V tolerant.
What is the difference between ISB and ISB1 standby current in the IDT71256SA15TPI?
ISB (40 mA max) activates when CS is pulled above VIH (≥2.2 V); ISB1 (15 mA max) activates only when CS exceeds VHC (VCC–0.2 V, ~4.8 V at 5 V). The IDT71256SA15TPI achieves deeper power savings in ISB1 mode, but requires precise high-level CS signaling - critical for battery-backed industrial systems where every milliamp matters.
Is the IDT71256SA15TPI pin-compatible with other 28-pin SRAMs like the HM62256 or AS6C2016?
No - while all are 32K × 8 SRAMs in 28-pin packages, the IDT71256SA15TPI uses a unique pinout: A0–A14 occupy Pins 1–2, 23–28, and 10–12; I/O0–I/O7 are on Pins 13–20; CS is Pin 21, OE is Pin 22, WE is Pin 24. The HM62256 and AS6C2016 assign these signals to different pins - direct replacement requires PCB redesign for the IDT71256SA15TPI.
IDT71256SA15TPI 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:
- 15ns
- Access Time:
- 15 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
IDT71256SA15TPI FAQ
1.How can I place an order for IDT71256SA15TPI through Aetrix?
Please submit a Request for Quotation (RFQ) for IDT71256SA15TPI 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 IDT71256SA15TPI reliable?
The price and inventory of IDT71256SA15TPI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IDT71256SA15TPI is usually 5 days.
3.What payment methods are accepted for IDT71256SA15TPI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IDT71256SA15TPI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for IDT71256SA15TPI?
IDT71256SA15TPI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your IDT71256SA15TPI 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 IDT71256SA15TPI?
For technical support, including IDT71256SA15TPI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IDT71256SA15TPI requirements.
6.How does Aetrix verify that IDT71256SA15TPI is sourced from the original manufacturer or authorized distributors?
All IDT71256SA15TPI 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 IDT71256SA15TPI meets industry standards.
7.What is the process for return or replacement of IDT71256SA15TPI?
All IDT71256SA15TPI units undergo pre-shipment inspection (PSI). If there is an issue with IDT71256SA15TPI, 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 IDT71256SA15TPI part is unused and in its original packaging.
Return procedure for IDT71256SA15TPI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
IDT71256SA15TPI Tags
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