This is a MP2148 Low Iq DC-DC Buck regulator breakout board.  The Monolithic Power MP2148 is a DC/DC buck regulator capable of 1A continuous output current from a 2.3V-to-5.5V input voltage with excellent load and line regulation. All of this is achieved at a mere 11uA of quiescent current.  Fault protections include cycle-by-cycle current limiting and thermal shutdown. The MP2148 is available in an ultra-small QFN- 6 (1.0mmx1.5mm) package and requires a low value inductor of only 1uH and can provide >90% efficiency. The smPWR-MP2148-ADJ provides an easy to use breakout board for the MP2148 measuring only 7.8x9.9mm. All pins are all mapped to standard 2.54mm/0.1” headers. This allows for use in a standard bread-board or to be ‘wired’ into an application. The header-header spacing is 7.62mm (300mil). The smPWR-MP2148-ADJ comes pre-configured for a 3.0V output but can be modified to provide a 1.8V output by simply moving R3(0603) 0ohm jumper. By default the EN line is pulled to Vin via R1(0ohm jumper).  For external control for Enable/Disable simply remove R1. All SMSTRS smMEM, smSENSR, smCOM, smBAT, smPWR products are compatible with the Sensor Maestros Wireless Sensor Platforms that provide Rapid prototyping for Sensor and BTLE applications. The smPWR-MP2148-ADJ can be plugged into ANY of the smPWR sockets in the smRF-WB and smWSP-ARD rapid prototyping sensor plugin boards. smWSP-ARD: Arduino compatible IoT Sensor Rapid Prototyping Platform MP2148 Datasheet For orders over 100 fill out this form