> A powerful microprocessor in your charger?
> One unexpected component is a tiny circuit board with a microcontroller, which can be seen above. This 16-bit processor constantly monitors the charger's voltage and current. It enables the output when the charger is connected to a Macbook, disables the output when the charger is disconnected, and shuts the charger off if there is a problem. This processor is a Texas Instruments MSP430 microcontroller, roughly as powerful as the processor inside the original Macintosh.
I'm not surprised at all. Microcontrollers are ubiquitous. There's little reason to use something like a 555 timer anymore. I wouldn't have been surprised if this had been a 32-bit ARM MCU (or a 8-bit PIC).
On one project I was on, we used a 16-bit MCU for a power controller. Cost less than twenty cents, and we got a lot of functionality out of it (you can cram a bunch of complex logic into 2K of code).
Near the end of that project, the hardware engineers came to us and apologized; they had managed to source a part for the same price with twice the code space. Could have used that, would have saved quite a bit of space optimization effort.
Should have had your supply chain people push the vendor/distributor on price of the half code space part to make all of that cramming NRE worth it. ;-)
Yeah, it wouldn't surprise me if this is fairly common, especially when you consider what happens when a lipo battery has a 'problem'. I'd want whatever's charging that up to be as exacting as possible.
All the charging circuitry resides in the laptop itself, the AC adapter is just a power supply. The reason why there is all this complexity is the MagSafe connector that makes it physically trivial to short the power pins together, which given the power levels involved might very well be plausible fire hazard.
I'm not surprised at all. Microcontrollers are ubiquitous. There's little reason to use something like a 555 timer anymore. I wouldn't have been surprised if this had been a 32-bit ARM MCU (or a 8-bit PIC).