Analog Devices Inc./Maxim Integrated DS1245Y-120IND+

Overview

DS1245Y-120IND+ from Maxim Integrated is a 1024k (131,072 × 8) nonvolatile static RAM with lithium backup, industrial temperature rating (–40°C to +85°C), ±10% V_CC tolerance (4.5V–5.5V), and 70 ns access time. It replaces volatile SRAM, EEPROM, or Flash in data-critical systems requiring automatic power-loss protection and 10-year data retention without external circuitry.

For engineers reviewing the DS1245Y-120IND+ datasheet, DS1245Y-120IND+ pinout, DS1245Y-120IND+ application, or DS1245Y-120IND+ equivalent, key selection criteria include write-protection voltage threshold (4.25V), JEDEC-standard 32-pin DIP package compatibility, battery-freshness seal behavior, and self-contained power-switching during V_CC decay or recovery.

Technical Context

The DS1245Y-120IND+ integrates SRAM, lithium battery, and real-time V_CC monitoring circuitry in a monolithic 32-pin EDIP package. Its control logic automatically enables battery backup when V_CC falls below 4.25V and forces write protection, while disconnecting the lithium source until first power-up to preserve capacity.

It operates as a byte-wide parallel memory with full static timing: CE/OE/WE control signals define read/write cycles, address inputs A0–A16 select 131,072 locations, and DQ0–DQ7 provide bidirectional data transfer - all compliant with standard microprocessor bus protocols without glue logic.

Key Specifications

Pinout & Package

DS1245Y-120IND+ uses a 32-pin JEDEC-standard Extended DIP (EDIP) package, 740-mil width, wave- or hand-solderable only (not reflow-compatible). The package integrates SRAM, lithium battery, and power-control circuitry into a single hermetically sealed unit.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS1245AB-70IND+, DS1245Y-120IND+ trades tighter V_CC regulation for broader supply adaptability and retains identical industrial temp rating and 70 ns timing; versus STK12C68-AW50I, it offers double density, integrated battery, JEDEC pinout, and no layout change requirement.

Availability

DS1245Y-120IND+ is available at Aetrix Electronics and suitable for industrial data loggers, medical device memory backup, and avionics black box recorders requiring stable component supply, long-lifecycle support, and guaranteed nonvolatile retention under uncontrolled power conditions.

Supply support for DS1245Y-120IND+ 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

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and nonvolatile memory solutions for industrial, medical, and automotive applications.

The DS1245Y-120IND+ belongs to Maxim's nonvolatile SRAM product line, engineered to eliminate external battery management and provide deterministic, maintenance-free data retention in mission-critical systems.

FAQ

What is the exact memory organization of the DS1245Y-120IND+?

The DS1245Y-120IND+ is organized as 131,072 words × 8 bits (1024 kbit total), with 17 address lines (A0–A16) and an 8-bit bidirectional data bus (DQ0–DQ7). This structure provides direct byte-addressable compatibility with standard 128k × 8 SRAM interfaces and eliminates the need for external address decoding logic in most microcontroller-based systems.

Does the DS1245Y-120IND+ require external components to achieve nonvolatile operation?

No, the DS1245Y-120IND+ requires zero external components for nonvolatile functionality. Its monolithic 32-pin EDIP package integrates the SRAM array, lithium energy source, and real-time V_CC monitoring/control circuitry. The device automatically switches to battery backup and enables write protection when V_CC drops below 4.25V - no capacitors, regulators, or discrete protection ICs are needed.

How does the freshness seal mechanism work in the DS1245Y-120IND+?

The DS1245Y-120IND+ ships with its internal lithium cell electrically disconnected. The seal remains intact until the user applies V_CC ≥ 4.25V for the first time, at which point an internal switch permanently connects the battery. This preserves full electrochemical capacity, ensuring the rated 10-year data retention begins only after initial system power-up - not from manufacturing date.

Is the DS1245Y-120IND+ compatible with standard 32-pin DIP sockets used for conventional SRAMs?

Yes, the DS1245Y-120IND+ uses a JEDEC-standard 32-pin 740-mil Extended DIP footprint with identical pinout to common 128k × 8 volatile SRAMs. It fits directly into existing sockets without PCB modification, enabling drop-in replacement in legacy designs while adding autonomous nonvolatile protection and 10-year data retention.

What happens to the DS1245Y-120IND+ during rapid V_CC transients or brownouts?

During V_CC decay, the DS1245Y-120IND+ detects out-of-tolerance conditions within 1.5 µs and immediately disables write capability, places all inputs in "don't care" state, and drives outputs to high impedance. When V_CC falls below ~3.0V, the lithium source powers the SRAM - ensuring uninterrupted data retention even during sub-millisecond brownouts or noisy supply events.