Renesas 71256L100DB

Overview

71256L100DB from Renesas Electronics is a 256K-bit (32K × 8) low-power CMOS static RAM with military-grade reliability, 100 ns maximum access time, –55°C to +125°C operating temperature range, and 2V data retention capability. It serves as non-volatile memory backup in avionics control units, radar signal buffers, and hardened telemetry systems requiring persistent state during brownout.

For engineers reviewing the 71256L100DB datasheet, 71256L100DB pinout, 71256L100DB application, or 71256L100DB equivalent, key selection criteria include military-qualified timing consistency at extended temperature, TTL-compatible I/O interface, ceramic DIP package robustness, and sub-5 µA standby current under full CMOS-level chip select.

Technical Context

This device implements a fully decoded 15-bit address space (A0–A14) driving a 32K × 8-bit memory array with asynchronous read/write control via independent CS, WE, and OE inputs. Its dual standby modes-TTL-level (ISB = 3 mA) and CMOS-level (ISB1 = 1.5 µA)-are triggered by logic-high chip select, enabling system-level power gating without external circuitry.

The 71256L100DB uses high-reliability CMOS fabrication compliant with MIL-STD-883 Class B, supporting deterministic 100 ns tAA and tACS timing across the full military temperature range. Data retention at 2V (ICCDR ≤ 800 µA) is guaranteed for all grades, with no external battery switching required.

Key Specifications

Pinout & Package

28-pin 600 mil ceramic dual in-line package (CD28), hermetically sealed for high-reliability military deployment. Pin layout matches JEDEC MS-001 standard with 0.6-inch body width and 0.1-inch lead pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 71256L100DB, the 71256S100DB trades ultra-low standby power for higher noise immunity in noisy 5 V rail environments, while CY62256LL-100ZC offers surface-mount convenience at the expense of environmental ruggedness and data retention capability.

Availability

71256L100DB is available at Aetrix Electronics and suitable for avionics flight control, radar signal buffering, and secure telemetry storage requiring stable component supply across extended temperature and long product lifecycles.

Supply support for 71256L100DB 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 automotive, industrial, and infrastructure markets.

The 71256L series was designed specifically for high-reliability military and aerospace applications demanding extended temperature operation, hermetic packaging, and battery-backed data retention without external circuitry.

FAQ

What is the guaranteed data retention voltage for the 71256L100DB?

The 71256L100DB guarantees data retention down to 2.0 V (VDR ≥ 2.0 V) across its full military temperature range (–55°C to +125°C), with typical ICCDR ≤ 800 µA. This enables direct connection to 2 V lithium backup cells without voltage regulation or supervisory circuits, and is explicitly validated in Table 11 of the Renesas datasheet revision Aug.06.20.

Does the 71256L100DB support both TTL and CMOS-level chip select inputs?

Yes, the 71256L100DB supports two distinct standby modes based on CS input level: ISB (TTL-level, CS > VIH = 2.2 V) draws 3 mA, while ISB1 (CMOS-level, CS > VHC = VCC – 0.2 V) draws only 1.5 µA. This dual-threshold design allows flexible integration with either TTL or CMOS system controllers without external level-shifting, as confirmed in Table 8 of the datasheet.

Is the 71256L100DB pin-compatible with other members of the 71256 family?

Yes, the 71256L100DB shares identical pinout, package footprint (CD28), and functional interface with all 71256S/L variants including 71256S25DB, 71256L25DB, and 71256S100DB. Address, data, and control signals map identically across speed grades and power variants, enabling drop-in replacement within the same temperature grade and package type, as verified in the Pin Configurations diagram (Figure 2) and Truth Table (Table 2).

What is the maximum power dissipation rating for the 71256L100DB?

The 71256L100DB has an absolute maximum power dissipation (PT) rating of 1.0 W, applicable across commercial, industrial, and military temperature grades per Absolute Maximum Ratings Table 3. This limit governs thermal design margins when operating at 5.5 V supply with worst-case dynamic current (ICC = 115 mA), and must be respected to ensure long-term reliability in hermetic ceramic DIP packaging.

How does the 71256L100DB handle output contention during write cycles?

During write cycles, the 71256L100DB places I/O0–I/O7 into high-impedance state when CS and WE are both asserted (LOW), preventing bus contention. Output drivers are disabled within tWHZ ≤ 40 ns after WE goes HIGH, and remain off until the next valid read cycle begins, as defined in AC Electrical Characteristics Table 13 and Timing Waveform Figure 10. This behavior eliminates need for external bus transceivers in shared-memory architectures.