Datasheet LTC3865, LTC3865-1 (Analog Devices) - 6

LTC3865/LTC3865-1
TYPICAL PERFORMANCE CHARACTERISTICS Effi ciency and Power Loss Effi ciency vs Load Current Effi ciency vs Load Current vs Input Voltage
100 100 100 5 FIGURE 16 CIRCUIT 90 90 90 80 80 EFFICIENCY 4 80 70 70 POWER LOSS (W) BURST BURST 70 60 60 3 DCM CCM 50 50 DCM 60 CCM POWER LOSS 40 40 50 2 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) 30 30 40 20 20 1 VIN = 12V VIN = 12V 10 V 30 OUT = 1.5V 10 VOUT = 1.2V FIGURE 16 CIRCUIT FIGURE 16 CIRCUIT 0 0 20 0 0.01 0.1 1 10 100 0.01 0.1 1 10 100 0 10 20 30 LOAD CURRENT (A) LOAD CURRENT (A) INPUT VOLTAGE (V) 3865 G23 3865 G24 3865 G25
Load Step Load Step Load Step (Burst Mode Operation) (Forced Continuous Mode) (Pulse-Skipping Mode)
VOUT VOUT 100mV/DIV 100mV/DIV AC- VOUT AC- COUPLED 100mV/DIV COUPLED AC- COUPLED IL IL IL 5A/DIV 5A/DIV 5A/DIV I I LOAD ILOAD LOAD 5A/DIV 5A/DIV 5A/DIV 500mA 500mA 500mA TO 7A TO 7A TO 7A V 40μs/DIV 3865 G01 IN = 12V 40μs/DIV 3865 G02 VIN = 12V 40μs/DIV 3865 G03 VIN = 12V VOUT = 1.5V VOUT = 1.5V VOUT = 1.5V FIGURE 16 CIRCUIT FIGURE 16 CIRCUIT FIGURE 16 CIRCUIT
Inductor Current at Light Load Prebiased Output at 1V Coincident Tracking
FORCED RUN CONTINUOUS RUN1 2V/DIV MODE 2V/DIV VOUT1 = 1.5V 5A/DIV 1Ω LOAD 500mV/DIV V Burst Mode OUT = 1.5V 500mV/DIV OPERATION 5A/DIV VOUT2 = 1.2V VTRACK/SS 1Ω LOAD PULSE- 1V/DIV 500mV/DIV SKIPPING MODE 5A/DIV V 2μs/DIV 3865 G04 40ms/DIV 3865 G05 IN = 12V 40ms/DIV 3865 G06 VOUT = 1.5V ILOAD = 100mA FIGURE 16 CIRCUIT 3865fb 6