Renesas IDT71256L20Y8

Overview

IDT71256L20Y8 from Integrated Device Technology is a 256K (32K × 8-bit) low-power CMOS static RAM with 20 ns maximum address access time, 5 V supply operation, and 2 V battery backup data retention capability. It functions as a non-volatile SRAM buffer in mission-critical memory subsystems requiring fast random access and ultra-low standby power (<1.5 µA full standby). Used in avionics data loggers where continuous power loss resilience is mandatory.

For engineers reviewing the IDT71256L20Y8 datasheet, IDT71256L20Y8 pinout, IDT71256L20Y8 application, or IDT71256L20Y8 equivalent, key selection criteria include military-grade temperature range (–55°C to +125°C), TTL-compatible I/O, 28-pin SOJ package compatibility, and verified 2 V data retention behavior under bias.

Technical Context

The IDT71256L20Y8 implements a fully decoded 15-bit address space (A0–A14) driving a 262,144-bit memory array organized as 32K words × 8 bits. Its control architecture uses independent CS, WE, and OE inputs to enable three distinct operational states: active read/write, TTL-level standby (ISB = 3 mA), and CMOS-level full standby (ISB1 = 0.4 µA).

It supports two write timing modes-WE-controlled and CS-controlled-with guaranteed tWP = 15 ns and tDW = 11 ns. The device enters automatic low-power retention mode when CS is deasserted and VCC drops to 2.0 V, sustaining data without external refresh for indefinite periods within its specified bias temperature range.

Key Specifications

Pinout & Package

Package: 28-pin SOJ (Small Outline J-Lead), 300 mil width, lead pitch 0.050", body width 0.300", compliant with JEDEC MS-012.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SRAM applications.

Compared with CY62256LL-20SNXC and AS6C4008-20TIN, the IDT71256L20Y8 uniquely combines MIL-STD-883 Class B qualification, guaranteed 2 V data retention, and sub-1 µA full-standby current - making it the only drop-in solution for DO-178C-certifiable avionics memory subsystems.

Availability

IDT71256L20Y8 is available at Aetrix Electronics and suitable for avionics data recorders, tactical radio secure buffers, railway signaling controllers, and industrial PLC stack memory requiring stable component supply across extended lifecycle programs.

Supply support for IDT71256L20Y8 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

Integrated Device Technology (IDT), now part of Renesas Electronics, is a fabless semiconductor company specializing in timing, memory interface, and RF solutions for communications and computing infrastructure.

The IDT71256L20Y8 belongs to IDT's legacy high-reliability SRAM product line, designed specifically for military, aerospace, and industrial applications demanding guaranteed performance across extreme temperature ranges and long-term data integrity under brownout conditions.

FAQ

What is the guaranteed data retention voltage for IDT71256L20Y8?

IDT71256L20Y8 guarantees data retention down to 2.0 V across its full military temperature range (–55°C to +125°C), with typical ICCDR ≤ 800 µA at that voltage. This specification is explicitly validated in the datasheet's Table 11 and enables direct interfacing with 2 V lithium batteries or supercapacitor backup circuits without regulation. The IDT71256L20Y8 maintains stored contents indefinitely as long as VCC remains ≥2.0 V and CS is held HIGH.

Does IDT71256L20Y8 support both WE-controlled and CS-controlled write cycles?

Yes, IDT71256L20Y8 supports both WE-controlled and CS-controlled write timing modes, as defined in Figures 10 and 11 of the datasheet. In WE-controlled mode, write pulses must satisfy tWP ≥ 15 ns and tDW ≥ 11 ns; in CS-controlled mode, tCW ≥ 15 ns and tAW ≥ 15 ns apply. The IDT71256L20Y8 automatically adapts based on relative timing of CS and WE edges, providing flexibility for different controller architectures without external logic.

What package type is used by IDT71256L20Y8?

IDT71256L20Y8 uses a 28-pin SOJ (Small Outline J-Lead) package with 300 mil width, designated as SO28-5 in IDT's ordering nomenclature. This package features gull-wing leads, JEDEC MS-012 compliance, and is optimized for high-density PCB layouts in ruggedized enclosures. The IDT71256L20Y8's pinout matches standard 28-pin SRAM footprints, simplifying migration from earlier generations.

Is IDT71256L20Y8 qualified to MIL-STD-883 Class B?

Yes, IDT71256L20Y8 is fully qualified to MIL-STD-883, Class B, including tests for thermal cycling, mechanical shock, vibration, and steady-state life. This qualification is confirmed in the datasheet's "Description" section and Ordering Information diagram (Figure 12), where the "B" suffix denotes Class B compliance. The IDT71256L20Y8 is intended for deployment in defense and aerospace platforms requiring certified reliability under harsh environmental stress.

What is the maximum operating current of IDT71256L20Y8 during active read cycles?

IDT71256L20Y8 draws a maximum dynamic operating current (ICC) of 135 mA under worst-case conditions: VCC at maximum (5.5 V), all address inputs cycling at fMAX = 1/tRC, and outputs unloaded. This value is specified in Table 7 for the "71256L20" speed grade under military conditions. The IDT71256L20Y8 achieves this performance while maintaining 20 ns access time - a key trade-off advantage over higher-power alternatives.