The AP1522 is a step-up DC/DC converter in a 5-Lead low profile. SOT25 package. The AP1522 switches at 1MHz that allows the use of tiny external components.
AP1522 - Step-Up DC/DC Converter ; Part No. AP1522 AP1522W AP1522WA ; Description, Step-Up DC/DC Converter ; File Size, 162.65K / 8 Page ; Maker, ANACHIP[Anachip ...