This report presents a Circuit Analysis on the Knowles' KMM1 MEMS microphone, which consists of a MEMS microphone and an application-specific integrated circuit (ASIC) die mounted in the same surface mount acoustic package. The ASIC die of the KMM1 MEMS microphone is manufactured in a four metal, double polysilicon 250 nm bipolar CMOS (Bi-CMOS) process. This chip, with a die size of 0.81 mm by 0.84 mm, carries the die markings 19380-001.