这款芯片使用过，很不错。开关频率高，纹波小，输入电压宽，使用电感小，占用pcb小。
LTC3115-1应用笔记
40V, 2A Synchronous
Buck-Boost DC/DC
Converter
Wide VIN Range: 2.7V to 40V
n Wide VOUT Range: 2.7V to 40V
n 1A Output Current for VIN ≥ 3.6V, VOUT = 5V
n 2A Output Current in Step-Down Operation
for VIN ≥ 6V
n Programmable Frequency: 100kHz to 2MHz
n Synchronizable Up to 2MHz with an External Clock
n Up to 95% Efficiency
n 30μA No-Load Quiescent Current in Burst ModeR
Operation
n Ultralow Noise Buck-Boost PWM
n Internal Soft-Start
n 3μA Supply Current in Shutdown
n Programmable Input Undervoltage Lockout
n Small 4mm 5mm 0.75mm DFN Package
n 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
Switch C (From SW2 to PGND) 150 mΩ
Switch D (From PVOUT to SW2) 150 mΩ
N-Channel Switch Leakage PVIN = PVOUT = 40V 0.1 10 μA
PVCC/VCC External Forcing Voltage 4.58 5.5 V
VCC Regulation Voltage IVCC = 1mA 4.33 4.45 4.58 V
振荡频率和RT曲线图
Burst Mode Operation输出纹波
软启动波形
PWM Mode纹波
PWM/SYNC (Pin 16/Pin 19):当此引脚置高电平时使用内部振荡频率，通过RT来设置频率大小。 |
