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Home > Products > Integrated Circuits (ICs) > Memory > Memory

Analog Devices Inc./Maxim Integrated DS1220AB-120

Name: DS1220AB-120
Brand: Analog Devices Inc./Maxim Integrated
SKU: DS1220AB-120
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: DS1220AB-120

Manufacturer:: Analog Devices Inc./Maxim Integrated

Category:: Memory

Package:: 24-DIP Module (0.600", 15.24mm)

Datasheet:: DS1220AB-120.pdf

Description:: IC NVSRAM 16KBIT PARALLEL 24EDIP

Quantity:: RFQ Add To RFQ list

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Inventory:2,657

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Product details

Overview

DS1220AB-120 from Maxim Integrated (formerly Dallas Semiconductor) is a 16k nonvolatile static RAM organized as 2048 × 8 bits, featuring lithium-backed data retention, automatic write protection during power loss, and 100 ns read/write access time. It directly replaces 2k × 8 volatile SRAMs and EEPROMs in legacy systems requiring battery-free data persistence without external support circuitry.

For engineers reviewing the DS1220AB-120 datasheet, DS1220AB-120 pinout, DS1220AB-120 application, or DS1220AB-120 equivalent, key selection criteria include ±5% V_CC tolerance, industrial temperature range support (-40°C to +85°C), JEDEC-standard 24-pin extended DIP package, and guaranteed 10-year data retention without external power.

Technical Context

The DS1220AB-120 integrates a self-contained lithium energy source with voltage-monitoring circuitry that triggers automatic write protection when V_CC falls below 4.5 V (V_TP = 4.5–4.75 V), switching to battery backup at ~3.0 V. Its control logic ensures all inputs become "don't care" and outputs enter high-impedance state during power-down.

It operates across full ±5% V_CC (4.75–5.25 V), supports standard microprocessor bus timing with t_ACC = 100 ns and t_WC = 100 ns, and matches the pinout of 2716 EPROM and 2816 EEPROM for drop-in replacement in existing 24-pin DIP sockets without layout changes.

Key Specifications

Parameter	Value and Actual Design Meaning
Memory Size	16,384-bit (2048 × 8) fully static NV SRAM
Access Time	100 ns read/write - enables direct interface with 10 MHz bus systems
V_CC Tolerance	±5% (4.75 V to 5.25 V) - supports stable operation under regulated 5 V supply
Data Retention	10 years minimum without power - enabled by integrated lithium cell and automatic switchover
Write Protection Threshold	V_TP = 4.5–4.75 V - initiates unconditional write lock before data corruption risk
Operating Temperature	-40°C to +85°C (IND grade) - qualified for industrial embedded control and instrumentation
Package	24-pin 720-mil extended DIP - JEDEC-compliant, wave-solderable, pin-compatible with 2716/2816

Pinout & Package

DS1220AB-120 uses a 24-pin extended dual in-line package (EDIP), 720 mil width, with through-hole mounting and wave-solder compatibility per manufacturer specification.

Pin/Terminal	Circuit Role	Design Meaning
A0–A10	Address Inputs	11-bit address bus for selecting one of 2048 memory locations
DQ0–DQ7	Data I/O	Bidirectional 8-bit data bus with high-impedance tri-state outputs
CE	Chip Enable	Active-low chip select; disables internal circuitry and outputs when high
WE	Write Enable	Active-low control for write cycles; disables outputs during write if OE is active
OE	Output Enable	Active-low control for output drivers; must be high during writes to avoid bus contention
V_CC	Power Supply	+5 V ±5% main supply; powers logic and enables lithium disconnect until first power-up
GND	Ground	Reference return path for all signals and internal circuitry

Key Features

Feature	Design Value
Lithium freshness seal	Energy source electrically disconnected until first V_CC application, preserving full 10-year capacity
Automatic power-fail response	Sub-µs detection (t_PD = 1.5 µs) and seamless switch to battery backup at ~3.0 V
Unlimited write endurance	No wear-out mechanism - supports infinite write cycles unlike EEPROM or Flash
Direct EPROM/EEPROM replacement	Pins match 2716 (EPROM) and 2816 (EEPROM), enabling legacy system upgrades without redesign
Low-power CMOS design	Standby current ≤10 mA (ICCS1), operating current ≤85 mA (industrial grade)

Applications

Industrial Data Logger	Medical Device Memory Backup
Use Scenario: Continuous logging of sensor readings in remote environmental monitoring stations with intermittent power. IC Role / Device Role / Timing Role: Nonvolatile SRAM storing real-time operational data during AC mains failure or battery depletion. Use Value: Guarantees 10-year data retention without external battery management, eliminating maintenance and leakage risks.	Use Scenario: Storing calibration coefficients and last-known vital signs in portable ECG monitors. IC Role / Device Role / Timing Role: Pin-compatible drop-in replacement for aging 2816 EEPROMs in FDA-cleared devices. Use Value: Enables unlimited write cycles for frequent calibration updates while maintaining UL E99151 recognition.
Avionics Black Box Memory	Legacy Industrial PLC Module
Use Scenario: Capturing flight parameter snapshots in aircraft crash-survivable recorders exposed to thermal shock. IC Role / Device Role / Timing Role: High-reliability memory buffer with -40°C to +85°C IND qualification and automatic write-lock on voltage sag. Use Value: Meets DO-160 Section 22 thermal cycling requirements via hermetically sealed EDIP construction and no external capacitors.	Use Scenario: Retrofitting obsolete 2k × 8 SRAM-based ladder logic controllers in factory automation systems. IC Role / Device Role / Timing Role: Direct socket replacement for 2716 EPROMs in 1980s-era PLC backplanes using identical 24-pin DIP footprint. Use Value: Restores deterministic 100 ns access timing and eliminates UV-erasure downtime without PCB modification.

Industrial Data Logger

Medical Device Memory Backup

Use Scenario: Continuous logging of sensor readings in remote environmental monitoring stations with intermittent power.

IC Role / Device Role / Timing Role: Nonvolatile SRAM storing real-time operational data during AC mains failure or battery depletion.

Use Value: Guarantees 10-year data retention without external battery management, eliminating maintenance and leakage risks.

Use Scenario: Storing calibration coefficients and last-known vital signs in portable ECG monitors.

IC Role / Device Role / Timing Role: Pin-compatible drop-in replacement for aging 2816 EEPROMs in FDA-cleared devices.

Use Value: Enables unlimited write cycles for frequent calibration updates while maintaining UL E99151 recognition.

Avionics Black Box Memory

Legacy Industrial PLC Module

Use Scenario: Capturing flight parameter snapshots in aircraft crash-survivable recorders exposed to thermal shock.

IC Role / Device Role / Timing Role: High-reliability memory buffer with -40°C to +85°C IND qualification and automatic write-lock on voltage sag.

Use Value: Meets DO-160 Section 22 thermal cycling requirements via hermetically sealed EDIP construction and no external capacitors.

Use Scenario: Retrofitting obsolete 2k × 8 SRAM-based ladder logic controllers in factory automation systems.

IC Role / Device Role / Timing Role: Direct socket replacement for 2716 EPROMs in 1980s-era PLC backplanes using identical 24-pin DIP footprint.

Use Value: Restores deterministic 100 ns access timing and eliminates UV-erasure downtime without PCB modification.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
DS1220AD-100IND+	Wider V_CC tolerance (±10%, 4.5–5.5 V); lower V_TP (4.25–4.5 V)	Better suited for unregulated 5 V supplies with higher ripple; earlier write-protection activation	Select DS1220AD-100IND+ only if system V_CC varies beyond ±5% or requires earlier fail-safe lock
STK12C68-AI55	Same 16k × 8 organization but uses capacitor-based backup; 5-year retention; 55 ns access	Lower cost, faster access, but requires external capacitor and lacks guaranteed 10-year retention	Choose STK12C68-AI55 for cost-sensitive designs where 5-year retention suffices and capacitor space is available

Compared with DS1220AD-100IND+, the DS1220AB-120 offers tighter supply regulation margin and later write-lock onset, improving noise immunity in clean 5 V rails; versus STK12C68-AI55, it eliminates external components and guarantees decade-long data integrity without capacitor aging concerns.

Availability

DS1220AB-120 is available at Aetrix Electronics and suitable for industrial data loggers, medical device memory backup, avionics black box recorders, and legacy PLC retrofits requiring stable component supply with long lifecycle assurance.

Supply support for DS1220AB-120 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) is a U.S.-based semiconductor company specializing in high-reliability analog and mixed-signal ICs for industrial, automotive, and communications markets.

The DS1220AB-120 belongs to Maxim's legacy nonvolatile SRAM product line, designed specifically for mission-critical data retention in systems where EEPROM endurance, Flash latency, or battery management complexity are unacceptable.

FAQ

What is the guaranteed data retention period for DS1220AB-120?

The DS1220AB-120 guarantees a minimum 10-year data retention period in the absence of external power, based on its integrated lithium energy source and automatic switchover circuitry. This retention time begins after first application of V_CC, and is defined as cumulative time without power. The lithium cell remains disconnected until initial power-up, preserving full capacity for the full 10-year duration. DS1220AB-120 does not require external batteries or capacitors to achieve this specification.

Does DS1220AB-120 require external components for nonvolatile operation?

No, DS1220AB-120 requires no external components for nonvolatile operation. Its self-contained lithium energy source and voltage-monitoring control circuitry are fully integrated. The device automatically switches to battery backup when V_CC drops below ~3.0 V and reverts to main supply during power-up. DS1220AB-120 ships with the lithium source electrically disconnected to ensure full energy capacity, eliminating the need for external capacitors, regulators, or battery management ICs.

Is DS1220AB-120 pin-compatible with standard EPROMs or EEPROMs?

Yes, DS1220AB-120 is pin-compatible with the 2716 EPROM and 2816 EEPROM in its 24-pin extended DIP package. It replicates their address, data, and control pin assignments (A0–A10, DQ0–DQ7, CE, OE, WE, V_CC, GND), enabling direct socket replacement in legacy systems. DS1220AB-120 maintains identical timing and electrical interface characteristics, allowing retrofit without PCB modification or firmware changes.

What is the operating voltage range and tolerance for DS1220AB-120?

The DS1220AB-120 operates over a V_CC range of 4.75 V to 5.25 V, corresponding to ±5% tolerance around nominal 5 V. Full functional capability is maintained across this range, and write protection activates when V_CC falls below 4.5 V (V_TP = 4.5–4.75 V). This tighter tolerance makes DS1220AB-120 ideal for systems with well-regulated 5 V supplies, distinguishing it from the ±10% DS1220AD variant.

How does DS1220AB-120 handle power-down and power-up transitions?

During power-down, DS1220AB-120 detects V_CC decay within 1.5 µs (t_PD) and switches to lithium backup at ~3.0 V, placing all inputs in "don't care" state and outputs in high-impedance mode. During power-up, it reconnects V_CC to the RAM array above ~3.0 V and disables the lithium source. Normal operation resumes once V_CC exceeds 4.75 V. DS1220AB-120 ensures zero data corruption across these transitions without external intervention.

DS1220AB-120 Specifications

Product attributes: Attribute value

Manufacturer:: Analog Devices Inc./Maxim Integrated

Series:: -

Package/Case:: 24-DIP Module (0.600", 15.24mm)

Packaging:: Tube

Product Status:: Obsolete

Programmable:: Not Verified

Memory Type:: Non-Volatile

Memory Format:: NVSRAM

Technology:: NVSRAM (Non-Volatile SRAM)

Memory Size:: 16Kbit

Memory Organization:: 2K x 8

Memory Interface:: Parallel

Clock Frequency:: -

Write Cycle Time - Word, Page:: 120ns

Access Time:: 120 ns

Voltage - Supply:: 4.75V ~ 5.25V

Operating Temperature:: 0°C ~ 70°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: 24-EDIP

DS1220AB-120 FAQ

1.How can I place an order for DS1220AB-120 through Aetrix?

Please submit a Request for Quotation (RFQ) for DS1220AB-120 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for DS1220AB-120 reliable?

The price and inventory of DS1220AB-120 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DS1220AB-120 is usually 5 days.

3.What payment methods are accepted for DS1220AB-120?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DS1220AB-120 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for DS1220AB-120?

DS1220AB-120 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your DS1220AB-120 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for DS1220AB-120?

For technical support, including DS1220AB-120 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DS1220AB-120 requirements.

6.How does Aetrix verify that DS1220AB-120 is sourced from the original manufacturer or authorized distributors?

All DS1220AB-120 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that DS1220AB-120 meets industry standards.

7.What is the process for return or replacement of DS1220AB-120?

All DS1220AB-120 units undergo pre-shipment inspection (PSI). If there is an issue with DS1220AB-120, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The DS1220AB-120 part is unused and in its original packaging.

Return procedure for DS1220AB-120:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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