Datasheet LT3958 (Analog Devices) - 5

LT3958
Typical perForMance characTerisTics TA = 25°C, unless otherwise noted. Positive Feedback Voltage Negative Feedback Voltage Quiescent Current vs Temperature, VIN vs Temperature, VIN vs Temperature, VIN
1.604 –792 1.8 VIN = 80V 1.602 –794 VIN = 80V 1.600 V 1.7 IN = INTVCC = 5V VIN = 24V –796 V VIN = 24V 1.598 IN = 8V VIN = 8V –798 1.6 1.596 –800 VIN = 80V V V 1.594 IN = 24V IN = INTVCC = 5V V 1.5 IN = INTVCC = 5V QUIESCENT CURRENT (mA) –802 REGULATED FEEDBACK VOLTAGE (V) 1.592 REGULATED FEEDBACK VOLTAGE (mV) 1.590 –804 1.4 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) 3958 G01 3958 G02 3958 G03
Dynamic Quiescent Current Normalized Switching vs Switching Frequency RT vs Switching Frequency Frequency vs FBX
12 1000 120 10 100 8 80 (mA) 6 (kΩ) 100 60 I Q R T 4 40 2 NORMALIZED FREQUENCY (%) 20 0 10 0 100 200 300 400 500 600 700 800 900 1000 0 100 200 300 400 500 600 700 800 900 1000 –0.8 –0.4 0 0.4 0.8 1.2 1.6 SWITCHING FREQUENCY (kHz) SWITCHING FREQUENCY (kHz) FBX VOLTAGE (V) 3958 G04 3958 G05 3958 G06
Switching Frequency SW Pin Current Limit SW Pin Current Limit vs Temperature vs Temperature vs Duty Cycle
325 4.4 4.4 RT = 41.2k 320 4.3 4.3 315 4.2 4.2 310 305 4.1 4.1 300 4.0 4.0 295 3.9 3.9 290 3.8 3.8 SWITCHING FREQUENCY (kHz) 285 SW PIN CURRENT LIMIT (A) SW PIN CURRENT LIMIT (A) 280 3.7 3.7 275 3.6 3.6 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 0 20 40 60 80 100 TEMPERATURE (°C) TEMPERATURE (°C) DUTY CYCLE (%) 3958 G07 3958 G08 3958 G09 3958fa For more information www.linear.com/LT3958 5 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Typical Applications Package Description Revision History Typical Applications Related Parts