Datasheet LTC3852 (Analog Devices) - 5

LTC3852
TYPICAL PERFORMANCE CHARACTERISTICS Effi ciency vs Output Current Load Step and Mode Load Step (Burst Mode Operation)
100 I Burst Mode OPERATION LOAD ILOAD 10A/DIV 10A/DIV 5A TO 15A 1A TO 12A 80 IL IL 10A/DIV 60 10A/DIV CCM V V OUT OUT 40 100mV/DIV 100mV/DIV EFFICIENCY(%) AC-COUPLED AC-COUPLED PULSE-SKIPPING 20 3852 G04 3852 G05 V 50μs/DIV V 20μs/DIV OUT = 1.5V OUT = 1.2V V V IN1 = 3.3V IN1 = 3.3V FIGURE 16 CIRCUIT FIGURE 16 CIRCUIT FIGURE 17 CIRCUIT 0 0.01 0.1 1 10 100 LOAD CURRENT (A) 3852 G02
Load Step Load Step (Forced Continuous Mode) (Pulse-Skipping Mode) Inductor Current at Light Load
ILOAD ILOAD FORCED 10A/DIV 10A/DIV CONTINOUS 1A TO 12A 1A TO 12A MODE 5A/DIV IL IL Burst Mode 10A/DIV 10A/DIV OPERATION 5A/DIV VOUT VOUT PULSE- 100mV/DIV 100mV/DIV SKIPPING AC- AC- MODE 5A/DIV COUPLED COUPLED 3852 G06 3852 G07 3852 G08 V 20μs/DIV OUT = 1.2V V 20μs/DIV OUT = 1.2V V 1μs/DIV OUT = 1.5V VIN1 = 3.3V VIN1 = 3.3V VIN2 = 3.3V FIGURE 17 CIRCUIT FIGURE 17 CIRCUIT ILOAD = 500mA FIGURE 17 CIRCUIT
Start-Up with Prebiased Output Coincident Tracking with Master Ratiometric Tracking with Master at 0.5V Supply Supply
VMASTER VMASTER 0.5V/DIV 0.5V/DIV VOUT 1V/DIV TRACK/SS 0.5V/DIV VOUT 2A LOAD 0.5V/DIV VOUT 2A LOAD VFB 0.5V/DIV 0.5V/DIV 0V 0V 0V 3852 G09 20ms/DIV 3852 G10 100ms/DIV 3852 G11 10ms/DIV FIGURE 16 CIRCUIT FIGURE 16 CIRCUIT FIGURE 16 CIRCUIT 3852f 5