I recently saw an announcement from a major IC vendor, posted in September 2025, letting users know that “STMicroelectronics sets 20-year availability for popular automotive microcontrollers.” The news is that ST was committed to maintaining the cited parts for 20 years instead of their present 15-year assurance.
“Good for them” was my first thought, as that’s the right thig to do for both their OEM and actual vehicle customers. After all, with the average age of cars on the road in the United States approaching 15 years and with little sign of slowing down or even leveling off, that makes sense.
There are two presumed reasons for the longer lifetime. First, cars are built better; the “rust-bucket” and “fall apart” tendencies of many of those pre-1980/90 cars have greatly diminished due to better design, materials, paints, tests, and processes. Second, the cost of a new car is so high that even costly repairs make sense for many.
Ironically, those less reliable, mostly mechanical cars did have one major virtue: they were repairable then and can generally be repaired/restored even today. Many of their old parts are available via specialty sources either as “new old stock” (NOS) or slightly used. And those that can’t be sourced can be machined or 3D printed if the owner has time and resources.
The issue is not limited solely to cars; unavailable mechanical assemblies are a very different case than electronic ones. In 2022, a team at Verisurf was contracted by the U.S. Air Force to reverse engineer and recreate a 300-piece “throttle quadrant” from the E-3 Airborne Early Warning and Control System (AWACS), by disassembling an existing unit piece-by-piece (Figure 1). See “Reverse Engineering the Boeing E-3 Sentry’s Secondary Flight Controls”.
Figure 1 This throttle quadrant from an E-3 AWACS radar aircraft was recreated via precise piece-by-piece measurement and fabrication of each of its 300 pieces. Source: Verisurf
They used a combination of tools, including basic calipers, advanced metrology systems, CAD/CAM software, close-up photographs, and more to capture and then recreate this control unit-top tolerances of better than 0.005 inches.
For the computers-on-wheels electronics of today’s cars, it’s a very different reality. Will you be able to get an engine control module, or one of the other hundred or so MCU-based modules, even 15 years from now? I’m betting the answer is “no” or “very unlikely,” but we’ll have to wait and see how that story unfolds.
The issue of unavailable parts is not limited solely to automobiles, although that is the largest and most visible application. Unlike most consumer products, there are many areas where useful lives of 20, 30, and more years are expected. Among these are industrial applications, railways, mil/aero, critical infrastructure, and even some home systems such as HVACs.
The challenge of replacement parts and their relatively low volume is not being ignored, as the ST announcement shows. The U.S. Defense Microelectronics Agency (DMEA) has instituted an Advanced Technology Supplier Program V (ATSP V) with 13 companies that, among other objectives, includes approaches to developing and creating components in ultra-low volumes for repair and replacement.
What about “analog”?
With all these legitimate concerns about long-term component availability, there’s one interesting aspect. One fact does stand out: unlike digital ICs and processors, the analog world has a different mindset. Analog-circuit designers tend to stick with a component that they have used successfully, even if it’s a few years old and could easily be replaced by a nominally better part.
Ther are several reasons for this tactic. Once an analog part is in the signal chain meeting specs, there’s a reluctance to take change on a new part and design which may have unknown issues and idiosyncrasies. Factors such as parasitics, layout, and power-supply sensitivity (to cite a few) likely will affect design validation, in contrast to the field experience with the existing design.
There are classic analog parts that have been available for decades, and while not recommended for new designs, they are still available if needed for repair, replacement, or even a newer design. Even better, if they are not available, there is often a drop-in replacement with superior performance; this is especially the case for basic 8-pin op amps.
I can think of three “ancient” analog components as examples:
- The AD574 “complete” 12-bit A/D converter from Analog Devices, introduced in the 1978–1980, became the industry-standard ADC for microprocessor interfacing (Figure 2). It was notable for integrating a buried Zener reference clock and 3-state output buffers for direct 8/16-bit bus interfacing. While its die and process have been upgraded and it’s now available in other packages, you can still get it in the original 28-pin housing.
Figure 2 The 12-bit ADC was the first complete unit with “tight” specifications and is still offered 45 years after its initial release. Source: Analog Devices
- The INA133 instrumentation amplifier from Burr-Brown was introduced around 1998 (Burr-Brown was acquired by Texas Instruments in 2000), and it’s still offered in a variety of packages and grades by TI (Figure 3). Like AD574, it’s not recommended for new designs; you can see its top-tier specifications on page 40 of the 2000 Burr-Brown Product Selection Guide.
Figure 3 Burr-Brown’s INA133 instrumentation amplifier provided excellent performance with modest power requirements and has been continuously available since its introduction in 1998. Source: Texas Instruments
- Finally, we can’t look at the 555 timer-oscillator-multivibrator, a clear contender as one of the most classic components of all time and the longest-lived along with the 74 op amp (Figure 4). Devised by Hans Camenzind and marketed as an 8-pin DIP by Signetics in 1971, it’s still available in many versions, including duals and quads as well as CMOS variations. Despite its age, it’s often used to solve annoying timing and oscillator problems at low cost, and there are many “cookbooks” showing innovative ways in which it can be used.
Figure 4 It’s very likely that no IC has spawned more creative and clever design ideas and handbooks and solved as many circuit problems as the 555 timer-oscillator-multivibrator. Source: Wikipedia
There are others, of course, such as the 60-year-old 2N3905 or 2N2222 transistors—it doesn’t get more basic than that.
While many analog components have a long and viable life with their original or descendent vendors, there is even a solution for the many cases where that source does not want to manufacture or support that IC forever. Companies such as Rochester Electronics work out a formal arrangement and license to take over the rights, tooling, support, and test procedures for the parts. Users who need the part don’t need to consider grey-market or even counterfeit products; instead, they get ICs which are 100% legitimate but via a different supplier.
ST’s announcement is welcome, of course. I wish that more vendors would make that sort of commitment, difficult as it may be, or at least commit to licensing unwanted products to non-competing vendors. For now, if you want long-term continuity, stick with analog parts as much as possible.
Have you ever had to deal with repairing a product having electronic components that were no longer available, or even doing regular production on a long-lived product where you needed more than just a few? Did you find parts, or did you have to do a full redesign? How painful was that process?
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