Datasheet LTC3868 (Analog Devices) - 5

LTC3868
TYPICAL PERFORMANCE CHARACTERISTICS Efficiency and Power Loss vs Output Current Efficiency vs Output Current
100 10000 100 FIGURE 12 CIRCUIT 90 V 90 IN = 12V VIN = 5V V 80 OUT = 3.3V 1000 80 POWER LOSS (mW) 70 70 VIN = 12V 60 100 60 50 50 40 10 40 EFFICIENCY (%) EFFICIENCY (%) 30 Burst Mode 30 20 OPERATION 1 20 PULSE- 10 SKIPPING 10 VOUT = 3.3V FCM FIGURE 12 CIRCUIT 0 0.1 0 0.0001 0.001 0.01 0.1 1 10 0.0001 0.001 0.01 0.1 1 10 OUTPUT CURRENT (A) OUTPUT CURRENT (A) 3868 G01 3868 G02
Load Step Efficiency vs Input Voltage Load Step (Burst Mode Operation) (Forced Continuous Mode)
98 FIGURE 12 CIRCUIT 96 VOUT = 3.3V I V OUT = 4A OUT VOUT 94 100mV/DIV 100mV/DIV AC- AC- 92 COUPLED COUPLED 90 88 EFFICIENCY (%) 86 IL 2A/DIV IL 2A/DIV 84 82 80 0 5 10 15 20 25 28 20µs/DIV 3868 G04 VOUT = 3.3V 20µs/DIV 3868 G05 VOUT = 3.3V INPUT VOLTAGE (V) FIGURE 12 CIRCUIT FIGURE 12 CIRCUIT 3868 G03
Load Step (Pulse-Skipping Mode) Inductor Current at Light Load Soft Start-Up
VOUT FORCED V 100mV/DIV OUT2 CONTINUOUS 2V/DIV AC- MODE COUPLED Burst Mode V OPERATION OUT1 2V/DIV 2A/DIV IL 2A/DIV PULSE- SKIPPING MODE 20µs/DIV 3868 G06 VOUT = 3.3V 2µs/DIV 3868 G07 VOUT = 3.3V 20ms/DIV 3868 G08 FIGURE 12 CIRCUIT ILOAD = 200µA FIGURE 12 CIRCUIT FIGURE 12 CIRCUIT 3868fe For more information www.linear.com/LTC3868 5 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Typical Performance Characteristics Pin Functions Operation Package Description Typical Application Related Parts