Datasheet LT3685 (Analog Devices) - 4

LT3685
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C unless otherwise noted. Effi ciency Effi ciency Maximum Load Current
100 90 4.0 VIN = 7V V 85 IN = 12V VIN = 12V 3.5 90 TYPICAL 80 V V IN = 34V 3.0 IN = 34V 80 75 VIN = 24V VIN = 24V 70 2.5 70 MINIMUM 65 EFFICIENCY (%) EFFICIENCY (%) 2.0 LOAD CURRENT (A) 60 60 V 55 1.5 OUT = 3.3V L: NEC PLC-0745-5R6 L: NEC PLC-0745-5R6 L = 4.7μH V V f = 800 kHz 50 OUT = 5V f: 800kHz 50 OUT = 3.3V f: 800kHz 1.0 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 5 10 15 20 25 30 LOAD CURRENT (A) LOAD CURRENT (A) INPUT VOLTAGE (V) 3685 G01 3685 G02 3685 G03
Maximum Load Current Switch Current Limit Switch Current Limit
3.5 4.0 4.5 TYPICAL 4.0 DUTY CYCLE = 10 % 3.5 3.0 3.5 3.0 3.0 2.5 2.5 DUTY CYCLE = 90 % 2.5 MINIMUM 2.0 2.0 2.0 LOAD CURRENT (A) 1.5 SWITCH CURRENT LIMIT(A) 1.5 SWITCH CURRENT LIMIT (A) 1.0 VOUT = 5V 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 75 100 125 150 INPUT VOLTAGE (V) DUTY CYCLE (%) TEMPERATURE (°C) 3685 G04 3685 G05 3685 G06
Switch Voltage Drop Boost Pin Current
700 80 70 600 60 500 50 400 40 300 TAGE DROP (mV) 30 VOL 200 BOOST PIN CURRENT (mA) 20 100 10 0 0 0 500 1000 1500 2000 2500 0 500 1000 1500 2000 2500 SWITCH CURRENT (mA) SWITCH CURRENT (mA) 3685 G07 3685 G08 3685fb 4