Datasheet LT3481 (Analog Devices) - 4

LT3481
TYPICAL PERFORMANCE CHARACTERISTICS Effi ciency (VOUT = 5.0V) Effi ciency (VOUT = 3.3V) Effi ciency
100 100 90 90 90 VIN = 12V VIN = 12V 85 80 80 VIN = 7V VIN = 24V 80 V 70 70 IN = 24V V 60 60 IN = 12V V 75 IN = 24V 50 50 70 40 40 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) 65 30 30 60 20 20 VOUT = 3.3V L: NEC PLC-0745-4R7 10 10 L: NEC PLC-0745-4R7 55 L = 10μH f: 800kHz f: 800kHz LOAD = 1A 0 0 50 0.0001 0.001 0.01 0.1 1 10 0.0001 0.001 0.01 0.1 1 10 0 0.5 1 1.5 2 2.5 3 LOAD CURRENT (A) LOAD CURRENT (A) SWITCHING FREQUENCY (MHz) 3481 G01 3481 G02 3481 G03
No Load Supply Current No Load Supply Current Maximum Load Current
80 400 4.0 TA = 25°C CATCH DIODE: DIODES, INC. PDS360 70 350 VIN = 12V 3.5 TYPICAL 60 300 VOUT = 3.3V 3.0 50 250 40 200 INCREASED SUPPLY 2.5 MINIMUM Y CURRENT (μA) Y CURRENT (μA) CURRENT DUE TO CATCH 30 150 DIODE LEAKAGE AT 2.0 SUPPL SUPPL HIGH TEMPERATURE LOAD CURRENT (A) 20 100 VOUT = 3.3V TA = 25°C 10 50 1.5 L = 4.7μH FRONT PAGE APPLICATION f = 800kHz 0 0 1.0 0 5 10 15 20 25 30 35 –50 –25 0 25 50 75 100 125 150 5 10 15 20 25 30 INPUT VOLTAGE (V) TEMPERATURE (°C) INPUT VOLTAGE (V) 3481 G04 3481 G05 3481 G06
Maximum Load Current Switch Current Limit Switch Current Limit
4.0 4.0 4.5 DUTY CYCLE = 10 % 4.0 3.5 3.5 TYPICAL 3.0 3.0 3.0 2.5 DUTY CYCLE = 90 % 2.5 2.5 2.0 MINIMUM 1.5 2.0 2.0 LOAD CURRENT (A) VOUT = 5.0V 1.0 SWITCH CURRENT LIMIT(A) SWITCH CURRENT LIMIT (A) T 1.5 A = 25°C 1.5 L = 4.7μH 0.5 f = 800kHz 1.0 1.0 0 5 10 15 20 25 30 0 20 40 60 80 100 –50 –25 0 25 50 75 100 125 INPUT VOLTAGE (V) DUTY CYCLE (%) TEMPERATURE (°C) 3481 G07 3481 G08 3481 G09 3481fc 4