Datasheet LT3975 (Analog Devices) - 6

LT3975
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. RT Programmed Switching Switching Frequency Frequency Frequency Foldback
780 350 700 720 300 600 250 500 660 200 400 600 150 300 RESISTOR (kΩ) 540 R T 100 200 SWITCHING FREQUENCY (kHz) 480 SWITCHING FREQUENCY (kHz) 50 100 420 0 0 –55 –25 5 35 65 95 125 155 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 0 0.2 0.4 0.6 0.8 1 1.2 TEMPERATURE (°C) SWITCHING FREQUENCY (MHz) FB PIN VOLTAGE (V) 3975 G19 3975 G20 3975 G21
Internal Undervoltage Lockout (UVLO) EN Thresholds PG Thresholds
6 1.09 1.12 EN RISING 1.08 5 1.11 1.07 1.10 4 1.06 1.09 FB RISING 3 1.05 1.08 1.04 1.07 FB FALLING INPUT VOLTAGE (V) 2 EN THRESHOLD (V) PG THRESHOLD (V) 1.03 1.06 1 EN FALLING 1.02 1.05 0 1.01 1.04 –55 –25 5 35 65 95 125 155 –55 –25 5 35 65 95 125 155 –55 –25 5 35 65 95 125 155 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) 3975 G22 3975 G23 3975 G24
Minimum Input Voltage, Minimum Input Voltage, VOUT = 5V VOUT = 3.3V Burst Frequency
6.5 5.0 900 VOUT = 5V VOUT = 3.3V fSW = 800kHz FRONT PAGE APPLICATION 800 6.0 4.5 VOUT = 5V 700 fSW = 800kHz TO RUN/TO START TO RUN/TO START 600 5.5 4.0 500 400 VOUT = 3.3V 5.0 3.5 fSW = 600kHz INPUT VOLTAGE (V) INPUT VOLTAGE (V) 300 4.5 3.0 SWITCHING FREQUENCY (kHz) 200 100 4.0 2.5 0 0 0.5 1 1.5 2 2.5 0 0.5 1 1.5 2 2.5 0 20 40 60 80 100 120 140 160 LOAD CURRENT (A) LOAD CURRENT (A) LOAD CURRENT (mA) 3975 G25 3975 G26 3975 G27 3975f 6 Document Outline FEATURES DESCRIPTION APPLICATIONS 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