Texas Instruments Changes The NE5532 And Others Into Incompatible Versions

June 3, 2026 by Maya Posch 45 Comments

First introduced in 1979 by Signetics, the NE5532 was a pretty spiffy dual op-amp for the time with low noise and low distortion. Over the years it has become a standard part that showed up in countless audio products, and has become a so-called jellybean generic component with Texas Instruments (TI) being one of countless manufacturers.

It being such a standard, multi-sourced part makes it thus even more puzzling that TI has now decided to completely overhaul this IC in a way that makes it incompatible with even the original Signetics NE5532. These changes are covered in detail by [Dave] of EEVblog as his mind is pretty much blown at such an incomprehensible change.

The changes entail an entirely different manufacturing process and a big change in specifications, while making no change to the part number. In revision K of the TI datasheet these changes are first seen, with some specifications changed for the better, like a higher unity gain bandwidth by 2 MHz, but a much slower slew rate.

Although the 5532 op-amps are multi-sourced, there are good reasons to just stick with manufacturers like TI, as that means receiving a product change notification (PCN) when anything changes. In the PCN related to this op-amp a change to process node is noted, along with other changes, but no reasoning.

Among the other big changes are a reduction in the supply voltage from 22 V to 18 V, and a halving of the ESD protection from 2 kV to 1 kV. Although it might be slightly more efficient on the new process node this way, it clearly comes with a lot of trade-offs that make it an overall worse op-amp, while also being incompatible with the same op-amp from other manufacturers.

In the video [Dave] goes through the datasheets of this jellybean part of other manufacturers, showing that they still have the original 1980s specifications. Only one exception here was the NE5532DR from Shenzhen HuaXuanYang Electronics, whose supply rail voltage is also 18 V for some reason, along with a similar internal transistor configuration that reduces the ESD resistance.

In addition to the NE5532 op-amp, it seems that TI also took an axe to the OPA134 op-amp, by removing its offset trim feature and listing the pins as ‘NC’, with a warning to not connect these pins and also worsening other specifications. This makes these similar jellybean parts incompatible, with no change to the part number. Worse is that it continues with the LMH6518, whose changes [Dave] argues might even kill oscilloscopes as they are commonly found in those.

Meanwhile the LM317M also got an overhaul, but here TI opted to give it a new part name, calling it the LM317MQ with at first glance no major degradations in the specifications, but instead some actual improvements. This makes it even more puzzling why TI didn’t give the other ICs a new part number to differentiate them from the jellybean part.

Until there’s some clarification from the side of TI, it might be a good idea to source these parts from a manufacturer that is not TI, especially when replacing these ICs in older devices.

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FLOSS Weekly Episode 869: Linux On Your Toaster

April 29, 2026 by Jonathan Bennett 4 Comments

This week Jonathan chats with Andrei, Mahir, and Praneeth, live on location at Texas Instruments! The team at TI has been working hard to provide really good Open Source support for Sitara processors, including upstreaming support to the mainline Linux kernel. We talk about the CI pipeline for these devices, the challenges of doing Open Source at a big company, and more. Check it out!

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Jon Peddie’s The Graphics Chip Chronicles On Graphics Controller History

January 1, 2026 by Maya Posch 17 Comments

Using computers that feature a high-resolution, full-color graphical interface is commonplace today, but it took a lot of effort and ingenuity to get to this point. This long history is the topic of [Dr. Jon Peddie]’s article series called The Graphics Chip Chronicles. In the first of eight volumes, the early days of the NEC µPD7220 and the burgeoning IBM PC.

Texas Instruments TMS34020 (Source: Wikimedia)

These are just brief overviews of these particular chips, of course, with a lot more detail to be found when you go digging. Details such as the NEC µPD7220 being the graphics chip in Japan’s PC-9800 series of computers which are famous for the amazingly creative art and games that this chip enabled.

While the average Hackaday reader is likely familiar with the IBM PC side of things, Texas Instruments’ graphics controllers, including the very interesting TMS34010 and successor TMS34020 which can be called the first proper graphical processing units, or GPUs, effectively a CPU with graphics-specific instructions.

Although it’s tempting to see computer graphics as a direct line from the days of monochrome graphic controllers to what we have today in our PCs, there were a lot of companies and countless talented individuals involved, including companies who built clones that would go on to set new standards. If you’re into reading through a few years worth of computer history articles by someone who has been in the industry for even longer, it’s definitely worth a read.

Thanks to [JohnS_AZ] for the tip.

Top image: NEC µPD7220 by Drahtlos – Own work, CC BY-SA 4.0)

The Texas Instruments branding with some schematic symbols in background.

More Than 100 Sub-Circuit Designs From Texas Instruments

October 15, 2025 by John Elliot V 19 Comments

We were recently tipped off to quite a resource — on the Texas Instruments website, there’s a page where you can view and download a compendium of analog sub-circuits.

Individual circuits can be downloaded in the form of PDF files. If you chose to register (which is free), you’ll also gain access to the pair of e-books listed at the bottom of the page: Analog Engineer’s Circuit Cookbook: Amplifiers and Analog Engineer’s Circuit Cookbook: Data Converters. The data converter circuits can be further subdivided into analog-to-digital converter (ADC) circuits and digital-to-analog converter (DAC) circuits.

There are more than 60 amplifier circuits including basic circuits, current sensing circuits, signal sources, current sources, filters, non-linear circuits (rectifiers/clamps/peak detectors), signal conditioning, comparators, sensor acquisition, audio, and integrated amplifier circuits using MSP430 microcontrollers.

You’ll also find 39 analog-to-digital converter (ADC) circuits including low-power, small size, and cost optimized circuits; level translation and input drive circuits; low-level sensor input circuits; input protection, filtering and isolation circuits; and commonly used auxiliary circuits. Finally, there are 15 digital-to-analog converter (DAC) circuits including audio outputs, auxiliary and biasing circuits, current sources, and voltage sources.

Thanks to [Lee Leduc] for letting us know over on the EEVblog Forum.

UNIX For A Legacy TI

September 26, 2025 by Bryan Cockfield 14 Comments

Although now mostly known as a company who cornered the market on graphing calculators while only updating them once a decade or so, there was a time when Texas Instruments was a major force in the computing world. In the late 70s and early 80s they released a line of computers called the TI-99 to compete (unsuccessfully) with various offerings from Commodore, and these machines were fairly robust for the time. They did have limited memory but offered a 16-bit CPU and plenty of peripherals, and now there’s even a UNIX-like OS that they can run.

This version of UNIX is called UNIX99 and is the brainchild of AtariAge forum member [mrvan] who originally wasn’t looking to develop a full operating system for this computer but rather a set of standard C libraries to help with other projects. Apparently the step from that to a UNIX-flavored OS wasn’t too big so this project was born. While the operating system doesn’t have a UNIX certification, it has most of the tools any of us would recognize on similar machines. The OS has support for most of the TI-99 hardware, file management, a basic user account system, and a command shell through which scripts can be written and executed.

That being said, the limitations of the hardware do come through in the operating system. There’s no multitasking, for example, and the small amount of memory is a major hurdle as well. But that’s what makes this project all the more impressive, and [mrvan] isn’t stopping here. He’s working on a few other improvements to this platform, and we look forward to seeing future releases. UNIX itself is extremely influential in the computing world, and has been used a the model for other homebrew UNIX-like operating systems on similar platforms of this era such as the Z80.

Thanks to [Stephen] for the tip!

Photo courtesy of Rama & Musée Bolo via Wikimedia Commons

The Microtronic Phoenix Computer System

September 15, 2025 by John Elliot V 4 Comments

A team of hackers, [Jason T. Jacques], [Decle], and [Michael A. Wessel], have collaborated to deliver the Microtronic Phoenix Computer System.

In 1981 the Busch 2090 Microtronic Computer System was released. It had a 4-bit Texas Instruments TMS1600 microcontroller, ran at 500 kHz, and had 576 bytes of RAM and 4,096 bytes of ROM. The Microtronic Phoenix computer system is a Microtronic emulator. It can run the original firmware from 1981.

Between them the team members developed the firmware ROM dumping technology, created a TMS1xxx disassembler and emulator, prototyped the hardware, developed an Arduino-based re-implementation of the Microtronic, designed the PCB, and integrated the software.

Unlike previous hardware emulators, the Phoenix emulator is the first emulator that is not only a re-implementation of the Microtronic, but actually runs the original TMS1600 firmware. This wasn’t possible until the team could successfully dump the original ROM, an activity that proved challenging, but they got there in the end! If you’re interested in the gory technical details those are here: Disassembling the Microtronic 2090, and here: Microtronic Firmware ROM Archaeology. Continue reading “The Microtronic Phoenix Computer System” →

How The TI-99/4A Home Computer Worked

September 11, 2025 by John Elliot V 57 Comments

Over on YouTube [The 8-Bit Guy] shows us how the TI-99/4A home computer worked.

[The 8-Bit Guy] runs us through this odd 16-bit home computer from back in the 1980s, starting with a mention of the mysterious extra “space” key on its antiquated keyboard. The port on the side is for two joysticks which share a bus, but you can find boards for compatibility with “newer” hardware, particularly the Atari-style joysticks which are easier to find. The AV port on the back is an old 5-pin DIN such as was typical from Commodore and Atari at the time (also there is a headphone port on the front). The other DB9 port on the back of the device is the port for the cassette interface.

The main cartridge interface is on the front right of the machine, and there’s a smaller expansion socket on the right hand side. The front interface is for loading software (on cartridges) and the side interface is for peripherals. The system boots to a now famous “press any key” prompt. (We know what you’re thinking: “where’s the any key!?” Thanks Homer.)

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