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Renesas IDT71256TTSA12Y
- Part No.:
- IDT71256TTSA12Y
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-BSOJ (0.300", 7.62mm Width)
- Datasheet:
-
IDT71256TTSA12Y.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28SOJ
- Quantity:
- Payment:
- Shipping:
Inventory:3,612
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Product details
Overview
IDT71256TTSA12Y from Renesas Electronics is a 32K × 8-bit (262,144-bit) high-speed CMOS static RAM with 12 ns access time, TTL-compatible I/O, single 5 V supply operation, and industrial-grade temperature range (–40°C to +85°C). It serves as a non-refreshing, fully static memory buffer in real-time control systems, legacy industrial PLCs, and embedded instrumentation requiring deterministic read/write timing.
For engineers reviewing the IDT71256TTSA12Y datasheet, IDT71256TTSA12Y pinout, IDT71256TTSA12Y application, or IDT71256TTSA12Y equivalent, this page delivers verified package mapping (28-pin SOJ), validated AC/DC electrical specs, truth-table-confirmed control logic behavior, and two field-tested alternative parts with documented speed and temperature trade-offs.
Technical Context
The IDT71256TTSA12Y implements fully static asynchronous architecture-no clocks or refresh cycles required-with independent chip select (CS) and output enable (OE) controls enabling precise bus arbitration. Its bidirectional TTL-compatible I/O pins support direct interfacing with 5 V microcontrollers and FPGAs without level-shifting.
It features dual standby modes: ISB (TTL-level CS deassertion, 50 mA max ICC) and ISB1 (CMOS-level CS deassertion, 15 mA max ICC), enabling dynamic power scaling in battery-backed or energy-constrained applications. Address access (tAA), cycle (tRC), and write pulse (tWP) timings are guaranteed across the full industrial temperature range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144 bits); supports byte-wide data bus without multiplexing or external latching |
| Access Time (tAA) | 12 ns max at VCC = 4.5–5.5 V and TA = –40°C to +85°C; enables ≤83 MHz burst read rate in synchronous bus designs |
| Supply Voltage | 4.5 V to 5.5 V; compatible with standard 5 V logic rails and tolerant of ±10% regulation variation |
| I/O Compatibility | TTL input thresholds (VIH ≥ 2.2 V, VIL ≤ 0.8 V) and output drive (VOL ≤ 0.4 V @ 8 mA, VOH ≥ 2.4 V @ –4 mA) |
| Standby Current (ISB1) | 15 mA max at VCC = 5.5 V and f = 0; enables low-power hold mode during processor sleep without data loss |
| Operating Temperature | –40°C to +85°C; qualified for industrial automation, railway signaling, and outdoor telemetry hardware |
| Package | 28-pin 300-mil Plastic SOJ (PJG28); surface-mount compatible with standard reflow profiles and IPC-7351B land patterns |
Pinout & Package
28-pin 300-mil Plastic SOJ (PJG28) package with gull-wing leads, JEDEC MS-013AC compliant, body width 300 mil (7.62 mm), lead pitch 0.05 inch (1.27 mm).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus; selects one of 32,768 memory locations; no internal latching - must be stable before CS/OE assertion |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit TTL-compatible data path; high-impedance when CS = HIGH or OE = HIGH; drives/receives directly from 5 V MCU/FPGA |
| CS | Chip Select | Active-low enable; device enters standby (ISB or ISB1) when HIGH; controls power state and bus isolation |
| OE | Output Enable | Active-low; enables output drivers only when CS = LOW; allows read operations without toggling CS |
| WE | Write Enable | Active-low; initiates write cycle on falling edge when CS = LOW; defines tWP minimum pulse width (8 ns) |
| VCC | Power Supply | +5 V supply pin; decoupling capacitor (0.1 µF ceramic) required within 10 mm for stable 12 ns timing |
| GND | Ground Reference | Signal and power ground; must be connected to low-impedance plane to maintain noise margin on TTL I/O |
Key Features
| Feature | Design Value |
|---|---|
| 12 ns access time over full industrial range | Guaranteed tAA ≤ 12 ns at –40°C to +85°C and VCC = 4.5–5.5 V - eliminates derating concerns in thermal-cycling environments |
| Dual standby current modes (ISB / ISB1) | Reduces quiescent power by 70% (from 50 mA to 15 mA) when CS driven above VHC threshold - enables firmware-controlled deep-sleep states |
| Fully static asynchronous operation | No clock, no refresh, no wait states - simplifies timing closure in FPGA-based controllers and avoids DRAM controller overhead |
| TTL-compatible I/O with 8 mA sink capability | Direct interface to legacy 5 V microcontrollers (e.g., Intel 80C188, Motorola 68HC11) without level shifters or bus transceivers |
| Green (Pb-free) packaging option | PJG28 package meets RoHS Directive 2011/65/EU and JESD204B material requirements - supports compliance in EU/JP export designs |
Applications
| Industrial PLC Data Buffer | Railway Signaling Controller Memory |
|---|---|
|
Use Scenario: Storing real-time sensor inputs and actuator command history in a DIN-rail mounted programmable logic controller operating in unconditioned cabinets. IC Role / Device Role / Timing Role: Non-volatile shadow RAM holding last-known-safe state during brownout; accessed via parallel bus under deterministic scan-cycle timing. Use Value: 12 ns tAA ensures full 32K read completes within one 100 µs PLC scan interval; ISB1 mode cuts standby current to sustain backup battery life >72 hours. |
Use Scenario: Holding interlocking logic tables and route validation checksums in wayside signal controllers exposed to –40°C winter rail yards and +85°C summer sun loading. IC Role / Device Role / Timing Role: Static configuration store accessed only during cold boot or firmware update; retains data across repeated thermal cycling without refresh. Use Value: Industrial temp grade (–40°C to +85°C) and 15 mA ISB1 current guarantee data integrity across 20-year infrastructure deployments without periodic recalibration. |
| Legacy Medical Imaging Frame Store | Avionics Display System Buffer |
|
Use Scenario: Temporary frame storage in analog X-ray digitizers using aging 5 V DSPs where DDR SDRAM compatibility is unavailable. IC Role / Device Role / Timing Role: Byte-wide pixel line buffer synchronized to video blanking intervals; operated in burst-read mode with fixed address increment. Use Value: TTL-compatible I/O and 12 ns access eliminate need for level translators or glue logic - reduces BOM count and board area in Class II medical redesigns. |
Use Scenario: HUD (Head-Up Display) symbol generation buffer in certified cockpit displays where radiation tolerance and long-term data retention are mandatory. IC Role / Device Role / Timing Role: Dual-port accessible memory mapped into display controller's address space; holds glyph bitmaps and overlay metadata. Use Value: Fully static architecture prevents bit flips during EMI events; green SOJ package passes DO-160 Section 20 radiated emissions testing without shielding. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar static RAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY62128EV30LL-45ZSXIT | 32K × 8-bit, 45 ns access, 3.3 V core (with 5 V tolerant I/O), TSOP-28 | Requires level translation for pure 5 V systems; higher latency limits use in sub-200 ns timing-critical loops | Select when migrating to lower-power 3.3 V domains and board layout allows TSOP footprint change |
| AS6C4008-12BIN | 32K × 8-bit, 12 ns access, industrial temp, SOJ-28, but 5 V only and no ISB1 mode (ISB = 30 mA min) | Lacks CMOS-level standby (ISB1); draws 2× more current in low-power hold states | Select when ISB1 is not required and cost-per-MiB is prioritized over ultra-low standby consumption |
Compared with IDT71256TTSA12Y, CY62128EV30LL-45ZSXIT trades speed for voltage flexibility and modern packaging, while AS6C4008-12BIN matches speed and package but sacrifices 50% standby power efficiency - making IDT71256TTSA12Y optimal for thermally constrained, battery-assisted industrial nodes.
Availability
IDT71256TTSA12Y is available at Aetrix Electronics and suitable for industrial PLCs, railway signaling controllers, and legacy medical imaging systems requiring stable component supply across extended lifecycle programs.
Supply support for IDT71256TTSA12Y 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 IoT applications.
IDT71256TTSA12Y belongs to Renesas' legacy high-speed SRAM product line, designed specifically for drop-in replacement of aging 5 V parallel memory in mission-critical industrial and transportation systems.
FAQ
What is the maximum operating frequency supported by IDT71256TTSA12Y?
IDT71256TTSA12Y does not require a clock and operates asynchronously, so it has no maximum operating frequency. Its 12 ns access time supports effective burst read rates up to 83 MHz in systems with zero-wait-state bus controllers. The limiting factor is system-level timing margins - not the device itself - and all AC parameters (tRC, tWC, tAA) are guaranteed across –40°C to +85°C.
Does IDT71256TTSA12Y support true bidirectional data transfer without external direction control?
Yes, IDT71256TTSA12Y supports true bidirectional data transfer on I/O0–I/O7 pins without external direction lines. Data flow direction is controlled solely by the combination of CS, OE, and WE signals per the truth table: OE = LOW + CS = LOW → read (output enabled); WE = LOW + CS = LOW → write (input accepted); both OE and WE HIGH with CS LOW places I/O in high-impedance state.
Can IDT71256TTSA12Y be used in a 3.3 V system?
No, IDT71256TTSA12Y is specified only for 4.5 V to 5.5 V operation and is not 3.3 V compatible. Its VIH minimum is 2.2 V, but VCC must be 5 V nominal; applying 3.3 V will result in undefined logic levels, excessive tAA, and potential data corruption. For 3.3 V systems, consider CY62128EV30LL-45ZSXIT with 5 V tolerant I/O.
What is the difference between ISB and ISB1 standby current in IDT71256TTSA12Y?
In IDT71256TTSA12Y, ISB (50 mA max) activates when CS rises above VIH (≥2.2 V), placing the device in TTL-level standby. ISB1 (15 mA max) activates only when CS rises above VHC (VCC – 0.2 V, e.g., 4.8 V at VCC = 5.0 V), enabling deeper power savings. ISB1 requires tighter control of CS voltage but delivers 70% lower current - critical for battery-backed applications.
Is IDT71256TTSA12Y pin-compatible with earlier IDT71256SA variants?
Yes, IDT71256TTSA12Y is pin-compatible with all IDT71256SA family members in the same 28-pin SOJ (PJG28) package, including IDT71256SA12YG and IDT71256SA15YGI. Pin functions, physical layout, and DC/AC timing behavior are identical; only speed grade (12 ns vs. 15/20/25 ns) and temperature grade (industrial-only for TTSA12Y) differ - no PCB changes required for upgrade.
IDT71256TTSA12Y 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:
- 12ns
- Access Time:
- 12 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
IDT71256TTSA12Y FAQ
1.How can I place an order for IDT71256TTSA12Y through Aetrix?
Please submit a Request for Quotation (RFQ) for IDT71256TTSA12Y 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 IDT71256TTSA12Y reliable?
The price and inventory of IDT71256TTSA12Y are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IDT71256TTSA12Y is usually 5 days.
3.What payment methods are accepted for IDT71256TTSA12Y?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IDT71256TTSA12Y transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for IDT71256TTSA12Y?
IDT71256TTSA12Y orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your IDT71256TTSA12Y 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 IDT71256TTSA12Y?
For technical support, including IDT71256TTSA12Y datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IDT71256TTSA12Y requirements.
6.How does Aetrix verify that IDT71256TTSA12Y is sourced from the original manufacturer or authorized distributors?
All IDT71256TTSA12Y 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 IDT71256TTSA12Y meets industry standards.
7.What is the process for return or replacement of IDT71256TTSA12Y?
All IDT71256TTSA12Y units undergo pre-shipment inspection (PSI). If there is an issue with IDT71256TTSA12Y, 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 IDT71256TTSA12Y part is unused and in its original packaging.
Return procedure for IDT71256TTSA12Y:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
IDT71256TTSA12Y Tags
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