Analog Devices Inc./Maxim Integrated DS1270AB-100

Overview

DS1270AB-100 from Maxim Integrated is a 16M-bit (2,097,152 × 8) nonvolatile static RAM with integrated lithium battery backup, ±5% V_CC tolerance (4.75–5.25 V), 70 ns access time, and industrial-grade operation up to +85°C. It autonomously switches to battery power below ~3.0 V, enabling data retention without external circuitry in embedded systems requiring persistent memory during brownouts or power loss.

For engineers reviewing the DS1270AB-100 datasheet, DS1270AB-100 pinout, DS1270AB-100 application, or DS1270AB-100 equivalent, key selection criteria include write-protection voltage (V_TP = 4.50–4.75 V), unlimited write cycles, 5-year data retention in battery mode, and compatibility with standard 8-bit microprocessor buses using CE/OE/WE control.

Technical Context

The DS1270AB-100 implements a self-monitoring power-fail detection circuit that triggers unconditional write protection when V_CC drops below V_TP, then seamlessly transfers RAM operation to its internal lithium cell at ~3.0 V. Its CMOS architecture ensures low standby current (100–250 µA) and full functionality across the entire ±5% supply range.

All 21 address lines (A0–A20) and 8 bidirectional data lines (DQ0–DQ7) interface directly with microprocessor buses without glue logic. The device enforces strict timing constraints: t_ACC = 70 ns, t_WC = 70 ns, and t_ODW = 25 ns, with OE/CE/WE active-low control matching standard SRAM protocols.

Key Specifications

Pinout & Package

DS1270AB-100 uses a 36-pin 740-mil Extended Dual In-line Package (EDIP) with 0.1-inch lead spacing and wave-solder compatible construction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK16C88-70I and ISL71091SEH, DS1270AB-100 delivers integrated power monitoring and lithium switching in a single 36-pin EDIP package, reducing design complexity and validation effort for industrial and medical systems where radiation hardness is not required.

Availability

DS1270AB-100 is available at Aetrix Electronics and suitable for industrial data loggers, medical device configuration storage, and telecom base station control requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.

Supply support for DS1270AB-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 semiconductor company specializing in precision analog, mixed-signal, and power management ICs for industrial, medical, and communications applications.

The DS1270AB-100 belongs to Maxim's nonvolatile SRAM product line, designed specifically to replace battery-backed DRAM and EEPROM in systems demanding instant-write capability, unlimited endurance, and autonomous power-loss recovery.

FAQ

What is the write-protection voltage threshold for DS1270AB-100?

The DS1270AB-100 asserts unconditional write protection when V_CC falls below V_TP = 4.50–4.75 V. This threshold is factory-trimmed and guaranteed across temperature and process variation. Once triggered, all inputs become don't-care and outputs go high-impedance, preventing corruption during brownout conditions. DS1270AB-100 maintains this behavior consistently across its full industrial temperature range.

Does DS1270AB-100 require external components to operate as a nonvolatile SRAM?

No, DS1270AB-100 requires no external capacitors, diodes, or power-switching transistors. Its integrated lithium cell, voltage monitor, and power-switching circuitry are fully self-contained. Only standard decoupling capacitors (per layout guidelines) and a clean +5 V ±5% supply are needed. DS1270AB-100 achieves true plug-and-play nonvolatility without additional support circuitry.

How does DS1270AB-100 differ from the DS1270Y-100 variant?

DS1270AB-100 operates over a tighter V_CC range (4.75–5.25 V, ±5%) and has a higher write-protection threshold (4.50–4.75 V) versus DS1270Y-100 (4.5–5.5 V, ±10%; V_TP = 4.25–4.5 V). Both share identical pinout, timing, and packaging, but DS1270AB-100 is optimized for systems with regulated 5 V supplies where tighter voltage margins improve noise immunity and reduce false triggers.

Is DS1270AB-100 compatible with standard microprocessor bus timing?

Yes, DS1270AB-100 complies with industry-standard SRAM timing: t_ACC = 70 ns, t_WC = 70 ns, t_OE = 35 ns, and t_CO = 70 ns. Its CE/OE/WE control protocol matches common 8051, Z80, and ARM9 bus interfaces. DS1270AB-100 requires no wait-state insertion when used with processors running ≤14 MHz, simplifying timing closure in legacy and new designs.

What is the expected data retention lifetime of DS1270AB-100 in battery mode?

DS1270AB-100 guarantees ≥5 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-but validated through accelerated life testing and statistical analysis per Maxim's reliability program. DS1270AB-100 meets this requirement across its full industrial temperature range.