ISL91117高效率同步升压转换器的4.2a开关和输出断开

　　The ISL91117 is a highly-integrated boost switching regulator for battery powered applications. The device provides a power supply solution for products using dual-cell or three-cell alkaline， NiCd or NiMH， or one-cell Li-ion or Li-polymer battery. This device is capable of delivering an output current of 1.5A with PVIN = 3.3V and VOUT = 5V. The use of a synchronous rectifier maximizes efficiency at high loads. No-load quiescent current of only 35µA optimizes efficiency under light-load conditions. Forced PWM and/or synchronization to an external clock may also be selected for noise sensitive applications. The ISL91117 is designed for standalone applications and supports 5V fixed output voltage or variable output voltages with an external resistor divider. Power supply solution size is minimized by a 2.34mm x 1.72mm WLCSP and a 2.6MHz switching frequency， which allows for the use of tiny， low-profile inductors and ceramic capacitors to minimize the size of the solution.