Datasheet LT3972 (Analog Devices) - 4

LT3972
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C unless otherwise noted. Effi ciency Effi ciency Effi ciency
100 100 100 3.0 VIN = 12V 90 90 VIN = 12V 90 2.5 TOTAL POWER LOSS (W) VIN = 30V 80 V V IN = 24V 80 IN = 30V 80 2.0 VIN = 24V 70 70 70 1.5 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) V 60 IN = 12V V 60 60 1.0 OUT = 5V VOUT = 3.3V VOUT = 5V L = 4.7μH L = 3.3μH L = 4.7μH f = 600kHz f = 600kHz f = 600kHz 50 50 50 0.5 0 0.5 1 1.5 2 2.5 3 3.5 0 0.5 1 1.5 2 2.5 3 3.5 0 0.5 1 1.5 2 2.5 3 3.5 OUTPUT CURRENT (A) OUTPUT CURRENT (A) OUTPUT CURRENT (A) 3972 G01 3972 G02 3972 G03
No-Load Supply Current No-Load Supply Current Maximum Load Current
130 400 5.5 VOUT = 3.3V CATCH DIODE: DIODES, INC. PDS360 350 TYPICAL 110 VIN = 12V 5.0 300 VOUT = 3.3V 90 4.5 250 INCREASED SUPPLY MINIMUM CURRENT DUE TO CATCH 70 200 DIODE LEAKAGE AT 4.0 HIGH TEMPERATURE 150 50 3.5 LOAD CURRENT (A) SUPPLY CURRENT (μA) SUPPLY CURRENT (μA) 100 VOUT = 3.3V 30 3.0 TA = 25°C 50 L = 4.7μH f = 600kHz 10 0 2.5 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) 3972 G04 3972 G05 3972 G06
Maximum Load Current Switch Current Limit Switch Current Limit
5.5 6.0 6.5 6.0 TYPICAL 5.5 5.0 5.5 DUTY CYCLE = 10 % 5.0 5.0 4.5 DUTY CYCLE = 90 % 4.5 MINIMUM 4.5 4.0 4.0 4.0 LOAD CURRENT (A) 3.5 VOUT = 5V 3.5 SWITCH CURRENT LIMIT (A) SWITCH CURRENT LIMIT (A) 3.0 TA = 25°C 3.5 L = 4.7μH 2.5 f = 600kHz 3.0 3.0 2.0 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) 3972 G07 3972 G08 3972 G09 3972fa 4