The Z0109MN 5AA4 is an integrated circuit from STMicroelectronics. It is an ultra-miniature, low dropout (LDO) regulator, with a maximum output current at 1A. It is designed to offer a high efficiency and low power consumption in a tiny package. The built-in thermal shutdown, over-current protection and over-temperature protection make it very safe to use. In addition, it features an adjustable output voltage that can be set using external voltage divider resistors. This part can be used in a variety of applications such as providing power supply to gaming systems, cellular phones and low-cost microcontrollers.