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When an integrated circuit is discontinued, most people first ask, “What part should we use instead?”
A better question to ask is, “How can we keep this product running with the least risk?”
This guide offers engineering, quality, and procurement teams a step-by-step process for replacing an obsolete IC, so you don’t rely only on a part-number search to make decisions.
Don’t start with just a partial part number or a distributor listing. Check the full ordering code using the manufacturer’s datasheet, your BOM, approved vendor list, and assembly records.
A suffix can change things like the package, tape-and-reel format, temperature rating, memory size, qualification grade, or lead-free status. Two part numbers that look almost the same might not be good substitutes.
A Product Change Notification (PCN) is also not the same thing as a discontinuance notice. A PCN may describe a manufacturing or product change, while an EOL or discontinuance notice communicates a product withdrawal and may identify last-order and final-delivery dates. Texas Instruments, for example, states that its PCN process identifies affected products, impact on form, fit, function, quality, or reliability, and relevant qualification information. Its discontinuance notices may also identify an applicable replacement product. TI product change and discontinuance guidance
There are four main options. The right one depends on technical risk, how long the product will take to make, available stock, certification requirements, and redesign costs.
| Route | When it may fit | Main control |
| Source the original IC | Product is near end of life; redesign is impractical; qualified stock is available | Source verification, lot control, incoming inspection |
| Use a drop-in alternate | A technically suitable alternate has the same functional and physical interfaces | Form-fit-function review and sample validation |
| Make a controlled redesign | The product has significant future demand or the alternate requires circuit/firmware changes | Engineering change control and qualification plan |
| Replace the functional block | No practical off-the-shelf replacement exists | Board, firmware, FPGA, or system redesign |
It can make sense to buy the original IC if the product won’t be made much longer, the board is hard to recertify, or there isn’t a qualified alternative.
Electronic Component Traceability Documents: A Buyer’s Checklist Before Purchase
Only consider an alternate a true drop-in replacement after you’ve checked it in the full application context.
Treat a redesign as an engineering change, not just a purchasing swap.
Legacy ASICs, custom controllers, specialized mixed-signal ICs, and discontinued processors may have no practical one-to-one alternative.
Create a comparison record for both the original IC and each replacement candidate.
| Review area | What to compare | Why it matters |
| Form | Package body size, pin pitch, exposed pad, lead finish, MSL, assembly format | Prevents PCB and assembly mismatch |
| Fit | Pinout, no-connect pins, reserved pins, test pins, footprint | Same package does not guarantee the same pin map |
| Power | Supply range, sequencing, current, UVLO, reset, shutdown behavior | Prevents startup and power-rail failures |
| Inputs and outputs | Logic thresholds, drive strength, pull-ups, bus levels, tolerances | Prevents interface failures |
| Timing | Clock limits, propagation delay, reset timing, conversion time, switching behavior | Critical for digital, interface, and control ICs |
| Analog behavior | Offset, gain, noise, bandwidth, stability, accuracy | Critical for op amps, ADCs, sensors, and regulators |
| Thermal behavior | Power loss, thermal resistance, derating, exposed-pad requirements | Reduces high-load and field-failure risk |
| Protection | ESD, reverse polarity, overcurrent, fault response | Affects robustness and certification |
| Firmware | Registers, boot mode, drivers, calibration, memory, debug interface | Determines software migration work |
| Qualification | Temperature grade, AEC status, reliability data, customer requirements | Required for regulated or harsh environments |
| Supply | Lifecycle, manufacturer support, lead time, second-source options | Avoids replacing one supply risk with another |
For example, compare performance at the real conditions of the application:
Engineering might find a great alternative that procurement can’t source reliably. Procurement might find stock that engineering can’t approve. You need both perspectives.
If there’s no stable, authorized source, assess the specific sourcing risks and what quality controls you’ll need. For high-risk or obsolete parts, don’t rely on general terms like “original stock”—ask for shipment-specific proof.
How to Source Obsolete Electronic Components Without Counterfeit Risk
Use a documented validation plan appropriate to the application risk.
Automotive and high-reliability programs need more than just matching the package and electrical specs.
Replacement projects for obsolete components often fail when a single team makes all decisions alone.
| Team | Primary responsibility |
| Hardware engineering | Electrical comparison, circuit impact, validation plan |
| Firmware engineering | Driver, register, boot, and software compatibility |
| Procurement | Availability, supplier options, lead time, MOQ, price |
| Supply-chain management | Lifecycle monitoring, inventory coverage, continuity plan |
| Quality | Traceability, inspection plan, exception controls |
| Program management | Timeline, cost, customer impact, approval gates |
Send your RFQ with the full MPN and all technical or quality requirements. A clear request helps you distinguish among qualified original stock, a temporary solution, and a long-term replacement.
Does obsolete mean there is a direct replacement?
No. Some manufacturers suggest a replacement, but many discontinued ICs don’t have a true drop-in option. You need to check each candidate for package, pinout, electrical, functional, firmware, qualification, and supply compatibility.
Can a pin-compatible IC be used without testing?
No. Pin compatibility is only part of what’s needed. You still need to review and test the candidate in the real circuit and environment.
Should we buy remaining stock or redesign the board?
It depends on how long the product will be made, yearly demand, redesign costs, certification needs, available stock, and long-term supply risks. Often, the best plan is to buy enough for now while planning a redesign for the future.
What is needed to identify an alternative IC?
Provide the full manufacturer part number, datasheet, package, function, voltage and temperature ranges, application details, quantity, expected product life, and any qualification or traceability requirements.
Is a manufacturer-recommended replacement automatically approved?
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