Analog Devices Inc./Maxim Integrated DS1265AB-100

Overview

DS1265AB-100 from Maxim Integrated (now Analog Devices) is an 8 Mbit nonvolatile static RAM organized as 1,048,576 × 8 bits, featuring integrated lithium battery backup, automatic write protection during power loss, and 70 ns read/write access time. It operates at +5V ±5%, supports industrial temperature range (-40°C to +85°C) when ordered with IND suffix, and retains data for ≥10 years without external power.

For engineers reviewing the DS1265AB-100 datasheet, DS1265AB-100 pinout, DS1265AB-100 application, or DS1265AB-100 equivalent, key selection considerations include V_TP = 4.50–4.75 V write-protection threshold, 36-pin 740-mil extended DIP package, CMOS-compatible timing, and self-contained power-fail detection logic enabling zero-support-circuitry microprocessor interfacing.

Technical Context

The DS1265AB-100 implements a fully static NV SRAM architecture with on-chip voltage monitoring, lithium energy source switching, and automatic high-impedance output disable during V_CC decay below ~3.0 V. Its control logic enforces unconditional write protection when V_CC falls below V_TP (4.50–4.75 V), eliminating risk of partial writes.

It uses standard parallel SRAM interface timing: t_ACC = 70 ns, t_RC = 70 ns, t_WC = 70 ns, with CE/OE/WE active-low control and address/data multiplexing absent - all 20 address lines (A0–A19) and 8 bidirectional data lines (DQ0–DQ7) are dedicated and asynchronous.

Key Specifications

Pinout & Package

DS1265AB-100 is supplied in a 36-pin 740-mil Extended Dual In-line Package (EDIP), RoHS-compliant (indicated by '+' suffix), with through-hole mounting and wave/hand-solder compatible leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK12C68-AW50 and AS6C8008-70TIN, the DS1265AB-100 uniquely integrates lithium power, automatic V_CC monitoring, and full 8 Mbit density in a drop-in-compatible 36-pin EDIP footprint - eliminating external components while guaranteeing 10-year retention without system-level intervention.

Availability

DS1265AB-100 is available at Aetrix Electronics and suitable for industrial data loggers, medical device configuration storage, and telecom base station control memory requiring stable component supply, long-term lifecycle support, and guaranteed nonvolatile retention without external backup circuitry.

Supply support for DS1265AB-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 (acquired by Analog Devices in 2021) designs precision analog, mixed-signal, and high-reliability semiconductor solutions for industrial, medical, and communications markets.

The DS1265AB-100 belongs to Maxim's nonvolatile SRAM product line, engineered specifically for mission-critical applications demanding zero-data-loss memory retention across unpredictable power conditions and extended temperature ranges.

FAQ

What is the minimum V_CC level at which DS1265AB-100 guarantees write protection activation?

The DS1265AB-100 activates unconditional write protection when V_CC falls below its specified V_TP threshold of 4.50 V (minimum), with typical activation at 4.62 V and maximum at 4.75 V. This ensures data integrity is preserved before the SRAM enters unstable operating margins, and the internal lithium source engages to maintain memory state. DS1265AB-100 is designed to enforce this behavior across its full industrial temperature range.

Does DS1265AB-100 require external circuitry to manage its lithium backup source?

No, DS1265AB-100 does not require external circuitry for lithium management. Its integrated power-switching circuit automatically disconnects the lithium cell until first application of V_CC > V_TP, then monitors V_CC continuously and switches to battery power within 1.5 µs when voltage drops below V_TP. DS1265AB-100 is explicitly designed for zero-support-circuitry operation, distinguishing it from discrete battery-backup SRAM solutions.

Can DS1265AB-100 be used as a direct replacement for standard 8 Mbit SRAMs like AS6C8008?

DS1265AB-100 shares identical 36-pin EDIP pinout and parallel interface timing (70 ns access, CE/OE/WE control) with many volatile 8 Mbit SRAMs, but is not a pin-for-pin functional replacement due to differences in power sequencing and V_CC tolerance. While address/data lines match, DS1265AB-100 requires strict adherence to its 4.75–5.25 V supply range and exhibits automatic write-protect behavior below 4.5 V - features absent in AS6C8008. System validation is required before substitution.

What is the expected data retention lifetime of DS1265AB-100 under continuous battery backup?

The DS1265AB-100 guarantees ≥10 years of data retention in the absence of external power, measured from the time V_CC is first applied (activating the lithium cell). This specification is assured by component selection, process control, and design - not production-tested per unit. DS1265AB-100 achieves this via hermetically sealed lithium energy source and low-leakage CMOS SRAM core, with retention unaffected by temperature cycling within -40°C to +85°C.

Is DS1265AB-100 compliant with RoHS and UL safety standards?

Yes, DS1265AB-100 is RoHS-compliant (lead-free), indicated by the '+' suffix in its ordering code (e.g., DS1265AB-70IND+). It is also UL-recognized under file E99151, confirming compliance with UL 60950-1 for information technology equipment. These certifications apply to the packaged device and support use in certified industrial and medical end equipment requiring traceable safety documentation. DS1265AB-100 meets both requirements without derating or special handling.