Datasheet LT3988 (Analog Devices) - 4

LT3988
Typical perForMance characTerisTics TA = 25°C, unless otherwise noted. Efficiency, VOUT = 2.5V Efficiency, VOUT = 3.3V Efficiency, VOUT = 5V
80 90 90 VIN = 12V VIN = 12V 75 85 85 VIN = 24V VIN = 12V VIN = 24V 70 80 80 V V IN = 48V IN = 48V VIN = 24V 65 75 75 VIN = 48V 60 70 70 EFFICIENCY (%) 55 EFFICIENCY (%) 65 EFFICIENCY (%) 65 50 60 60 45 f = 500kHz 55 55 V f = 500kHz f = 500kHz 40 BD = 3V 50 50 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 LOAD CURRENT (A) LOAD CURRENT (A) LOAD CURRENT (A) 3988 G01 3988 G02 3988 G03
Switch Current Limit Switch Current Limit Feedback Voltage vs Temperature vs Temperature vs Duty Cycle
0.760 2.5 2.5 DUTY CYCLE = 35% 0.755 2.0 2.0 TYPICAL TAGE (V) 0.750 1.5 1.5 MINIMUM CURRENT LIMIT (A) CURRENT LIMIT (A) FEEDBACK VOL 0.745 1.0 1.0 0.740 0.5 0.5 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 0 20 40 60 80 100 TEMPERATURE (°C) TEMPERATURE (°C) DUTY CYCLE (%) 3988 G04 3988 G05 3988 G06
Switching Frequency Switching Frequency vs RT vs Temperature Switching Frequency Foldback
2.5 10 1.2 2.3 2.1 1.0 1.9 5 1.7 1.5 0.8 1.3 0 NOMf/f 1.1 0.6 FREQUENCY (MHz) 0.9 0.7 FREQUENCY CHANGE (%) –5 0.4 0.5 0.3 0.1 –10 0.2 0 20 40 60 80 100 120 140 160 180 200 –50 –25 0 25 50 75 100 125 150 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 RT (kΩ) TEMPERATURE (°C) FEEDBACK VOLTAGE (V) 3988 G07 3988 G08 3988 G09 3988f 4 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 Package Description Typical Application Related Parts