Electronics

Today I wanted to use a magnetic sensor for a small project. I had three Honeywell 2SS52M sensors in my stock – a magnetoresistive switch, more sensitive than your usual Hall-effect based ones. For my project it didn’t matter, but since I had these lying around I could as well put them to some use.

Since I didn’t know the exact pinout of these TO-92-similar devices, I asked Google. The first link after the advertisements was the direct link to the datasheet on Honeywell’s homepage.

Happily I realized that it was supposed to have the same pinout as the more common Hall-effect sensors, e.g. the venerable A3144 from Allegro. When my AVR-programmer decided to switch itself off after connecting the finished circuit I got a bit suspicious, but not suspicious enough to not burn up two out of three of my sensors.

What had happened?

Well obviously there is a printing error in Honeywell’s most recent datasheet, dated March 2016. Figure 3 should show the pinout of the sensor, but if you compare it to an older (less fancy) version of the datasheet, which the internet hadn’t forgotten, then you will see the difference. I assume that Honeywell has not changed the actual pinout of the devices in production – let’s see and wait if they will answer my email pointing out their mistake.