Apollo4 Plus SoC Ambiq Apollo4 Plus SoC offers additional on-chip memory, enhanced graphics, and increased memory performance to the Apollo4 SoC family. The Apollo4 Plus allows next-generation wearables and smart device developers to supply more stunning user interface (UI) effects and overall user experience to take innovative products to the next level. The Apollo4 Plus SoC is built upon Ambiq’s proprietary Subthreshold Power-Optimized Technology (SPOT®) platform.