If you've been digging through op-amp datasheets or looking for a reliable dual operational amplifier for a DIY project, the M358 is a chip you'll run into sooner or later. The M358 is a dual operational amplifier that follows the classic LM358 footprint and behavior, which makes it a favorite for low-cost signal conditioning, sensor interfaces, and simple active filters. In this guide, I'll walk you through the M358 pinout, its key specifications, the most common equivalents, and where the chip actually shines in