从入门到应用，关于LTC3115同步降压-升压转换器

　　30μA No-Load Quiescent Current in Burst Mode Operation

　　Ultralow Noise Buck-Boost PWM

　　Internal Soft-Start

　　3μA Supply Current in Shutdown

　　Programmable Input Undervoltage Lockout

　　Small 4mm × 5mm × 0.75mm DFN Package

　　Thermally Enhanced 20-Lead TSSOP Package

　　引脚封装定义：

　　VCC Undervoltage Lockout Threshold VCC Falling 2.4-- 2.6 V

　　Oscillator Frequency RT = 35.7k l 900 1000 1100 kHz

　　Oscillator Operating Frequency l 100 2000 kHz

　　PWM/SYNC Clock Input Frequency l 100 2000 kHz

　　PWM/SYNC Input Logic Threshold l 0.5 1.0 1.5 V

　　Soft-Start Duration 9 ms

　　Feedback Voltage l 977 1000 1017 mV

　　Feedback Voltage Line Regulation VIN = 2.7V to 40V 0.1 %

　　Feedback Pin Input Current 1 50 nA

　　RUN Pin Input Logic Threshold l 0.3 0.8 1.1 V

　　RUN Pin Comparator Threshold VRUN Rising l 1.16 1.21 1.26 V

　　N-Channel Switch Resistance Switch A （From PVIN to SW1）

　　Switch B （From SW1 to PGND） 150 mΩ