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Renesas IDT71256TTSA15Y
- Part No.:
- IDT71256TTSA15Y
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-BSOJ (0.300", 7.62mm Width)
- Datasheet:
-
IDT71256TTSA15Y.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28SOJ
- Quantity:
- Payment:
- Shipping:
Inventory:2,319
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Product details
Overview
IDT71256TTSA15Y from Renesas Electronics is a 32K × 8-bit (262,144-bit) high-speed CMOS static RAM operating at 5V with 15ns access and cycle times, industrial temperature range (–40°C to +85°C), TTL-compatible I/O, and single-chip-select architecture. It serves as main or buffer memory in embedded controllers, legacy industrial PLCs, and instrumentation requiring deterministic asynchronous read/write timing without refresh.
For engineers reviewing the IDT71256TTSA15Y datasheet, IDT71256TTSA15Y pinout, IDT71256TTSA15Y application, or IDT71256TTSA15Y equivalent, key selection criteria include guaranteed 15ns tAA/tRC performance at industrial temperature, low ISB1 standby current (15mA), TSOP-28 package compatibility, and direct replacement capability for legacy 256K SRAM designs using A0–A14 addressing and I/O0–I/O7 bidirectional data bus.
Technical Context
The IDT71256TTSA15Y implements fully static asynchronous logic with no clocks or refresh cycles required. Its address decoder supports full 15-bit address space (A0–A14), and control logic decodes CS, OE, and WE independently to enable fast read (tOE = 7ns max) and write (tWP = 10ns min) operations.
It uses dual standby modes: TTL-level ISB (40mA max) when CS > VIH, and CMOS-level ISB1 (15mA max) when CS > VHC and all inputs are valid high/low - enabling power optimization in battery-backed or low-duty-cycle systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144 bits), fixed asynchronous SRAM array |
| Access Time (tAA) | 15 ns max - guarantees data valid within 15 ns of address stabilization under industrial conditions |
| Cycle Time (tRC) | 15 ns max - enables consecutive read/write operations every 15 ns without wait states |
| Supply Voltage | 4.5 V to 5.5 V - compatible with standard 5V TTL/CMOS system rails |
| Operating Temperature | –40°C to +85°C - qualified for industrial environments without derating |
| Standby Current (ISB1) | 15 mA max - achieved only when CS driven above VHC (≈4.8V), enabling ultra-low-power hold mode |
| I/O Interface | TTL-compatible bidirectional data bus (I/O0–I/O7) - directly interfaces with 5V microcontrollers and FPGAs |
Pinout & Package
Package: 28-pin TSOP Type I (PZG28), 8.1 mm × 13.4 mm body, 0.5 mm pitch, surface-mountable with gull-wing leads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit unidirectional address bus selecting one of 32,768 memory locations |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit TTL-compatible data path shared for read output and write input; high-impedance when disabled |
| CS | Chip Select | Active-low enable controlling device selection; determines ISB vs ISB1 standby mode based on voltage level |
| OE | Output Enable | Active-low control for data output driver; allows read operation while CS remains asserted |
| WE | Write Enable | Active-low signal initiating write cycle; overlaps with CS low to latch data into memory array |
| VCC | Power Supply | +5V supply pin; must be decoupled locally due to dynamic ICC up to 150 mA |
| GND | Ground | Reference return for all signals and power; requires low-inductance connection to minimize noise coupling |
Key Features
| Feature | Design Value |
|---|---|
| Industrial-grade timing guarantee | 15ns tAA/tRC fully specified and tested over –40°C to +85°C, not extrapolated |
| Dual standby power modes | ISB1 = 15mA (CMOS-level CS) reduces power by 63% vs ISB = 40mA (TTL-level CS) |
| No refresh or clock required | Fully static design eliminates external timing circuitry, simplifying PCB layout and firmware |
| TTL-compatible I/O drive | VOH ≥ 2.4V @ –4mA and VOL ≤ 0.4V @ 8mA ensures robust interfacing with legacy 5V logic |
| Green-compliant packaging | Halogen-free, lead-free TSOP package compliant with RoHS Directive 2011/65/EU |
Applications
| Industrial PLC Memory Buffer | Legacy Medical Instrument Data Log |
|---|---|
|
Use Scenario: Storing real-time sensor acquisition buffers and configuration registers in DIN-rail mounted programmable logic controllers. IC Role / Device Role / Timing Role: Asynchronous SRAM providing zero-wait-state data storage for ARM7 or 8051-based control engines with burst I/O. Use Value: 15ns tAA ensures deterministic response to interrupt-driven I/O scans; ISB1 mode cuts standby power during idle cycles in fanless enclosures. |
Use Scenario: Capturing analog-to-digital conversion streams from ECG or pressure sensors in portable diagnostic devices with battery backup. IC Role / Device Role / Timing Role: Non-refresh volatile memory holding last 30 seconds of waveform data before flash transfer. Use Value: TTL-compatible I/O eliminates level-shifter components; industrial temp rating supports operation inside sterilized enclosures. |
| Avionics Test Equipment Cache | Telecom Line Card Configuration Store |
|
Use Scenario: Holding calibration tables and FPGA configuration snapshots in ground-support test sets for flight control subsystems. IC Role / Device Role / Timing Role: Fast-access SRAM used as shadow memory for reconfigurable logic initialization and runtime parameter lookup. Use Value: TSOP-28 footprint matches legacy board layouts; 15ns cycle time enables full table reads within single CPU clock cycles. |
Use Scenario: Storing port mapping, VLAN settings, and firmware patch flags in carrier-grade DSLAM line cards operating in central office environments. IC Role / Device Role / Timing Role: Configuration SRAM retaining settings across hot-swap events and power cycling. Use Value: Dual standby modes allow deep sleep (ISB1) during maintenance windows while maintaining data integrity without capacitor hold-up. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-speed asynchronous SRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY62128EV30LL-45ZSXI | 32K × 8, 45ns access, 3.3V core (with 5V-tolerant I/O), -40°C to +85°C | Requires level translation for pure 5V systems; slower timing limits use in high-throughput buffering | Select when migrating to lower-voltage platforms and 45ns latency is acceptable |
| AS6C4008-15ZIN | 32K × 8, 15ns access, 5V supply, -40°C to +85°C, SOJ-28 package only | Same speed and temp grade but SOJ-28 only - incompatible with TSOP-28 PCB footprints | Choose only if redesigning for SOJ socketing or existing SOJ-based legacy boards |
Compared with IDT71256TTSA15Y, CY62128EV30LL-45ZSXI trades speed for voltage flexibility, while AS6C4008-15ZIN matches timing and temperature but lacks TSOP-28 packaging - making IDT71256TTSA15Y the sole drop-in replacement for TSOP-based industrial designs requiring 15ns performance.
Availability
IDT71256TTSA15Y is available at Aetrix Electronics and suitable for industrial automation, medical instrumentation, avionics test equipment, and telecom infrastructure requiring stable component supply across extended product lifecycles.
Supply support for IDT71256TTSA15Y 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 trusted embedded solutions for automotive, industrial, infrastructure, and IoT applications.
IDT71256TTSA15Y belongs to Renesas' legacy high-speed CMOS SRAM product line, designed specifically for industrial and aerospace systems demanding deterministic timing, wide temperature operation, and long-term supply stability without refresh overhead.
FAQ
What is the maximum guaranteed access time for IDT71256TTSA15Y across its full industrial temperature range?
The IDT71256TTSA15Y has a maximum guaranteed address access time (tAA) of 15 ns over the full –40°C to +85°C operating range, as verified per AC Electrical Characteristics Table 9 in the Renesas datasheet. This value applies to all commercial and industrial variants marked "15" in the speed suffix and is not derated at temperature extremes.
Does IDT71256TTSA15Y require an external clock or refresh circuitry?
No, the IDT71256TTSA15Y uses fully static CMOS memory cells and asynchronous control logic - it operates without any clock signal or periodic refresh cycles. This eliminates timing-critical clock distribution and simplifies integration with microcontrollers, FPGAs, and legacy 8-bit processors that lack dedicated DRAM controllers.
What is the difference between ISB and ISB1 standby current specifications for IDT71256TTSA15Y?
IDT71256TTSA15Y defines two standby modes: ISB (40 mA max) activates when CS exceeds VIH (≥2.2 V), while ISB1 (15 mA max) engages only when CS exceeds VHC (≈VCC – 0.2 V, typically ≥4.8 V at 5V). ISB1 delivers 63% lower current but requires stricter logic-level compliance on the chip select line.
Which package type does IDT71256TTSA15Y use, and is it RoHS-compliant?
IDT71256TTSA15Y uses the 28-pin TSOP Type I (PZG28) package - 8.1 mm × 13.4 mm body, 0.5 mm lead pitch. Per Renesas ordering information and datasheet revision history, this variant is green-compliant: halogen-free, lead-free, and compliant with RoHS Directive 2011/65/EU.
Can IDT71256TTSA15Y be used as a direct replacement for IDT71256SA15YG in SOJ-based designs?
No - IDT71256TTSA15Y uses TSOP-28 (PZG28) packaging, whereas IDT71256SA15YG uses SOJ-28 (PJG28). Though functionally identical and pinout-compatible at the signal level (A0–A14, I/O0–I/O7, CS, OE, WE, VCC, GND), the mechanical form factor and solder footprint differ significantly; PCB redesign is required for substitution.
IDT71256TTSA15Y Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 28-BSOJ (0.300", 7.62mm 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:
- 15ns
- Access Time:
- 15 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-SOJ
IDT71256TTSA15Y FAQ
1.How can I place an order for IDT71256TTSA15Y through Aetrix?
Please submit a Request for Quotation (RFQ) for IDT71256TTSA15Y 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 IDT71256TTSA15Y reliable?
The price and inventory of IDT71256TTSA15Y are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IDT71256TTSA15Y is usually 5 days.
3.What payment methods are accepted for IDT71256TTSA15Y?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IDT71256TTSA15Y transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for IDT71256TTSA15Y?
IDT71256TTSA15Y orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your IDT71256TTSA15Y 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 IDT71256TTSA15Y?
For technical support, including IDT71256TTSA15Y datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IDT71256TTSA15Y requirements.
6.How does Aetrix verify that IDT71256TTSA15Y is sourced from the original manufacturer or authorized distributors?
All IDT71256TTSA15Y 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 IDT71256TTSA15Y meets industry standards.
7.What is the process for return or replacement of IDT71256TTSA15Y?
All IDT71256TTSA15Y units undergo pre-shipment inspection (PSI). If there is an issue with IDT71256TTSA15Y, 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 IDT71256TTSA15Y part is unused and in its original packaging.
Return procedure for IDT71256TTSA15Y:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
IDT71256TTSA15Y 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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