AP3039 is a current mode high voltage low-side N-channel MOSFET controller which is ideal for boostregulators. It contains all the features needed to imple-ment single ended primary topology DC/DCconverters. The input voltage range of AP3039 is from 6V to 27V.Its operation frequency is adjustable from 400K to1MHz.The AP3039 has UVLO (Under Voltage Lock Out)circuit. It uses two external resistors to set the UVLOvoltage. The AP3039 also has an over output voltageprotection to limit the output voltage. The OVP volt-age can be set through external resistors. If the outputvoltage is higher than the OVP high threshold point, itwill disable the driver, when the output voltage dropsto the OVP low threshold point, it will enable thedriver. It also features a soft start to reduce the inrushcurrent when power on, the soft start time can be setthrough an external capacitor. AP3039 is available in QFN-3x3-16 package.