Datasheet LTC3769 (Analog Devices) - 5

LTC3769
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C unless otherwise noted. Efficiency and Power Loss Efficiency and Power Loss vs Output Current vs Output Current
100 10 100 10 90 80 1 90 EFFICIENCY 1 POWER LOSS (W) 70 POWER LOSS (W) 80 60 0.1 50 70 POWER 0.1 LOSS 40 VIN = 12V 0.01 EFFICIENCY (%) VOUT = 24V EFFICIENCY (%) 30 FIGURE 8 CIRCUIT 60 0.01 20 FCM EFFICIENCY 0.001 FCM LOSS 50 VIN = 12V 10 PULSE-SKIPPING EFFICIENCY VOUT = 24V PULSE-SKIPPING LOSS FIGURE 8 CIRCUIT 0 0.0001 40 0.001 0.01 0.1 1 10 0.0001 0.001 0.01 0.1 1 10 OUTPUT CURRENT (A) OUTPUT CURRENT (A) 3769 G01 3769 G02
Load Step Load Step Efficiency vs Input Voltage Forced Continuous Mode Burst Mode Operation
100 ILOAD = 2A LOAD STEP LOAD STEP 99 FIGURE 8 CIRCUIT 2A/DIV 2A/DIV INDUCTOR INDUCTOR 98 CURRENT V CURRENT OUT = 12V VOUT = 24V 5A/DIV 5A/DIV 97 VOUT VOUT 96 500mV/DIV 500mV/DIV EFFICIENCY (%) 95 200µs/DIV 3769 G04 VIN = 12V 200µs/DIV 3769 G05 VIN = 12V 94 VOUT = 24V VOUT = 24V LOAD STEP FROM 200mA TO 2.5A LOAD STEP FROM 200mA TO 2.5A FIGURE 8 CIRCUIT FIGURE 8 CIRCUIT 93 0 5 10 15 20 25 INPUT VOLTAGE (V) 3769 G03
Load Step Pulse-Skipping Mode Inductor Currents at Light Load Soft Start-Up
LOAD STEP FORCED 2A/DIV CONTINUOUS INDUCTOR MODE CURRENT 5A/DIV Burst Mode OPERATION 5A/DIV VOUT VOUT PULSE- 5V/DIV 500mV/DIV SKIPPING MODE V IN = 12V 200µs/DIV 3769 G06 V IN = 12V 5µs/DIV 3769 G07 V RUN 5V/DIV VOUT = 24V VOUT = 24V 0V LOAD STEP FROM 200mA TO 2.5A ILOAD = 200µA FIGURE 8 CIRCUIT FIGURE 8 CIRCUIT VIN = 12V 20ms/DIV 3769 G08 VOUT = 24V FIGURE 8 CIRCUIT 3769fa For more information www.linear.com/LTC3769 5 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Revision History Typical Application Related Parts