Analog Devices Inc./Maxim Integrated DS1220AB-100IND+

Overview

DS1220AB-100IND+ from Maxim Integrated (now Analog Devices) is a 16k nonvolatile static RAM organized as 2048 × 8 bits, featuring lithium-backed data retention, 100 ns read/write access time, ±5% V_CC tolerance (4.75–5.25 V), and industrial temperature operation (–40°C to +85°C). It directly replaces volatile 2k × 8 SRAMs and EEPROMs in battery-backed memory systems requiring zero write-cycle limits and automatic power-loss protection.

For engineers reviewing the DS1220AB-100IND+ datasheet, DS1220AB-100IND+ pinout, DS1220AB-100IND+ application, or DS1220AB-100IND+ equivalent, key selection criteria include guaranteed 10-year data retention without external power, JEDEC-standard 24-pin extended DIP package compatibility, automatic V_CC monitoring and write-protection activation below 4.5 V, and seamless microprocessor interfacing with no support circuitry required.

Technical Context

The DS1220AB-100IND+ integrates a self-contained lithium energy source and voltage-monitoring circuitry that triggers automatic write protection when V_CC drops below 4.5 V (V_TP), switching to battery backup at ~3.0 V. Its architecture eliminates need for external capacitors, supervisors, or backup controllers.

It operates as a drop-in replacement for 2716 EPROM and 2816 EEPROM pinouts while delivering SRAM-speed access (100 ns t_ACC, t_WC) and unlimited write endurance - unlike EEPROMs limited by erase cycles or volatile SRAMs requiring continuous power.

Key Specifications

Pinout & Package

DS1220AB-100IND+ uses a 24-pin extended dual in-line package (EDIP), 720 mil width, with through-hole mounting and RoHS-compliant lead finish (+ suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS1220AD-100IND+, the DS1220AB-100IND+ offers tighter V_CC regulation tolerance and higher write-protection threshold, improving noise immunity in clean 5 V systems; versus MAX6900AISA+, it delivers parallel-interface speed, infinite writes, and autonomous power-loss handling - eliminating firmware overhead and external supervision.

Availability

DS1220AB-100IND+ is available at Aetrix Electronics and suitable for industrial data loggers, smart meter firmware storage, and PLC configuration backup requiring stable component supply, long-term lifecycle assurance, and guaranteed RoHS compliance.

Supply support for DS1220AB-100IND+ 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, automotive, and communications markets.

The DS1220AB-100IND+ belongs to Maxim's legacy nonvolatile SRAM product line, engineered specifically for mission-critical data retention in systems where power interruption is unavoidable and EEPROM endurance or battery-backed controller complexity is unacceptable.

FAQ

What is the guaranteed data retention period for DS1220AB-100IND+?

The DS1220AB-100IND+ guarantees a minimum of 10 years of data retention in the absence of external power, based on its integrated lithium energy source and freshness seal that preserves full battery capacity until first power application. This retention period is defined as cumulative time without V_CC, starting from initial power-up, and is ensured by design - not statistical sampling.

Does DS1220AB-100IND+ require external circuitry for battery backup operation?

No, the DS1220AB-100IND+ requires no external circuitry for battery backup operation. Its internal lithium cell, voltage monitor, and power-switching logic are fully integrated. The device automatically disconnects the lithium source until first V_CC application, then monitors V_CC continuously and switches to backup power when voltage falls below ~3.0 V - all without external components.

Is DS1220AB-100IND+ pin-compatible with standard 24-pin memory devices?

Yes, the DS1220AB-100IND+ uses a JEDEC-standard 24-pin extended DIP package and matches the pinout of both the 2716 EPROM and 2816 EEPROM. This enables direct socket replacement in legacy designs without PCB changes, preserving existing layouts while upgrading to nonvolatile SRAM performance and infinite write endurance.

What is the write protection voltage threshold for DS1220AB-100IND+?

The DS1220AB-100IND+ asserts hardware write protection when V_CC falls below its V_TP threshold of 4.5–4.75 V. This early, deterministic lockout prevents partial writes and data corruption during power decay, and is distinct from the ~3.0 V switchover point where the lithium source powers the RAM array.

How does DS1220AB-100IND+ handle power-up and power-down transitions?

During power-down, the DS1220AB-100IND+ detects V_CC decay via internal monitoring, disables all inputs (making them "don't care"), places outputs in high-impedance, and switches to lithium backup at ~3.0 V. At power-up, it reconnects V_CC to the RAM and disconnects the lithium source once V_CC exceeds ~3.0 V, resuming full operation after crossing 4.75 V.