This report presents a Circuit Analysis of the Ambiq Micro Apollo die found inside the Ambiq Micro 512K Apollo component. The Apollo microcontroller (MCU) is a line of ultra-low-power, highly integrated MCUs designed for battery-powered devices including wireless sensors, IoT devices, and wearable electronics, such as activity and fitness monitors. This circuit analysis report presents the circuits from the analog portion of the die. The analyzed functional blocks include clock generator and voltage regulator, SAR ADC, oscillator and buck converter.