Analog Devices Inc./Maxim Integrated DS1249AB-100

Overview

DS1249AB-100 from Maxim Integrated is a 2048k (2,097,152-bit) nonvolatile static RAM organized as 262,144 × 8, featuring lithium-backed data retention, ±5% V_CC tolerance (4.75–5.25 V), and 70 ns read/write access time. It operates in commercial temperature range (0°C to +70°C) and uses a JEDEC-standard 32-pin 740-mil extended DIP package for embedded memory backup in industrial controllers and legacy systems.

For engineers reviewing the DS1249AB-100 datasheet, DS1249AB-100 pinout, DS1249AB-100 application, or DS1249AB-100 equivalent, key selection considerations include its automatic V_CC-monitored write protection at 4.50–4.75 V, unlimited write cycles, 10-year data retention without external power, and compatibility with standard SRAM bus timing.

Technical Context

The DS1249AB-100 integrates self-contained lithium battery switching circuitry that activates when V_CC falls below ~3.0 V, enabling seamless transition to battery-backed data retention mode. Its control logic unconditionally enables write protection during power loss, forcing all inputs to "don't care" and outputs to high-impedance.

It supports standard asynchronous SRAM interface timing with CE, OE, and WE controls, requiring no external support circuitry. The device monitors V_CC continuously and guarantees full functionality across its specified ±5% supply range while maintaining strict tACC = 70 ns and tWC = 70 ns performance.

Key Specifications

Pinout & Package

DS1249AB-100 is housed in a JEDEC-standard 32-pin 740-mil extended dual in-line package (EDIP), wave- or hand-solderable only, with lead temperature rated to +260°C for 10 seconds.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS1249Y-70# and STK12C68-A70, the DS1249AB-100 delivers tighter supply regulation tolerance and factory-sealed lithium longevity-critical for sealed industrial enclosures where field battery servicing is impractical.

Availability

DS1249AB-100 is available at Aetrix Electronics and suitable for industrial PLC data logging, medical device configuration storage, and avionics black box memory requiring stable component supply over extended production lifecycles.

Supply support for DS1249AB-100 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) is a U.S.-based semiconductor company specializing in precision analog, mixed-signal, and power management ICs for industrial, medical, and communications markets.

The DS1249AB-100 belongs to Maxim's nonvolatile SRAM product line, engineered specifically for systems demanding guaranteed data retention during unpredictable power loss-without external support components or firmware overhead.

FAQ

What is the guaranteed data retention period for DS1249AB-100 without external power?

The DS1249AB-100 guarantees minimum 10 years of data retention in the absence of external power, based on internal lithium cell capacity and hermetic sealing. This specification assumes first power application initiates the retention timer, and the device remains within storage temperature limits (−40°C to +85°C). The DS1249AB-100 achieves this through an electrically disconnected lithium source until initial V_CC application, preserving full energy capacity.

Does DS1249AB-100 require external circuitry to enable battery backup operation?

No, the DS1249AB-100 requires no external circuitry for battery backup operation. Its integrated power-switching circuit automatically connects the internal lithium cell when V_CC drops below ~3.0 V and disconnects it upon power restoration above that threshold. The DS1249AB-100 also features a freshness seal that keeps the lithium source inactive until first power-up, ensuring full 10-year retention capacity.

What is the write protection voltage range for DS1249AB-100?

The DS1249AB-100 asserts hardware write protection when V_CC falls within 4.50 V to 4.75 V, as defined by its V_TP parameter. This threshold is narrower than the DS1249Y variant and ensures early lockout before data corruption can occur during brownout conditions. The DS1249AB-100 enforces this protection unconditionally-no software or external signal is needed-and all inputs become "don't care" once triggered.

Can DS1249AB-100 operate with a 5 V ±10% supply?

No, the DS1249AB-100 is specified only for 5 V ±5% operation (4.75 V to 5.25 V). Using a ±10% supply violates its recommended DC operating conditions and risks premature write protection activation or functional instability. For ±10% tolerance, the DS1249Y-70# variant is the correct choice. The DS1249AB-100's tighter regulation ensures predictable timing and reliable V_TP behavior in regulated power environments.

Is DS1249AB-100 RoHS-compliant?

Yes, DS1249AB-100 is RoHS-compliant, indicated by the "#" suffix in its ordering code (e.g., DS1249AB-70#). It meets EU Directive 2011/65/EU requirements, including exemption for lead in glass frits used in ceramic packaging. All DS1249AB-100 units supplied by Aetrix Electronics carry full RoHS documentation and traceable compliance certification.