LTC3522

LTC3522 Synchronous 400mA Buck-Boost and 200mA Buck Converters FEATURES ■ Dual High Efficiency DC/DC Converters: Buck-Boost (VOUT: 2.2V to 5.25V, IOUT: 400mA for VIN > 3V, VOUT = 3.3V) Buck (VOUT: 0.6V to VIN, IOUT: 200mA) ■ 2.4V to 5.5V Input Voltage Range ■ Pin Selectable Burst Mode® Operation ■ 25μA Total Quiescent Current for Both Converters in Burst Mode Operation ■ Independent Power Good Indicator Outputs ■ Integrated Soft-Start ■ Thermal and Overcurrent Protection ■ <1μA Quiescent Current in Shutdown ■ Small 0.75mm × 3mm × 3mm QFN Package APPLICATIONS ■ Flash-Based MP3 Players ■ Medical Instruments ■ Digital Cameras ■ PDAs, Handheld PCs ■ Personal Navigation Devices , LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 6404251 and 6166527. DESCRIPTION The LTC®3522 combines a 400mA buck-boost DC/DC converter with a 200mA synchronous buck DC/DC converter in a tiny 3mm × 3mm package. The 1MHz switching frequency minimizes the solution footprint while maintaining high efficiency. Both converters feature internal soft-start and compensation, simplifying the design process. The buck converter is current mode controlled and utilizes an internal synchronous rectifier for high efficiency. The buck converter supports 100% duty cycle operation to extend battery life. If the PWM pin is held low, the buck converter automatically transitions from B...