Datasheet LTC3857-1 (Analog Devices) - 6

LTC3857-1
TYPICAL PERFORMANCE CHARACTERISTICS Total Input Supply Current EXTVCC Switchover and INTVCC vs Input Voltage Voltages vs Temperature INTVCC Line Regulation
500 6.0 5.2 VOUT1 = 3.3V 450 RUN2 = 0V 5.8 400 FIGURE 13 CIRCUIT 5.6 5.1 350 5.4 300 INTV VOLTAGE (V) 5.2 CC CC TAGE (v) 250 500μA 5.0 5.0 EXTV VOL CC RISING 200 4.8 CC 300μA V 150 AND INTV 4.6 EXTVCC FALLING INT SUPPLY CURRENT (μA) CC 4.9 100 4.4 NO LOAD EXTV 50 4.2 0 4.0 4.8 5 10 15 20 25 30 35 40 –45 –20 5 30 55 80 105 130 0 5 10 15 20 25 30 35 40 INPUT VOLTAGE (V) TEMPERATURE (°C) INPUT VOLTAGE (V) 38571 G10 38571 G11 38571 G12
Maximum Current Sense Voltage Maximum Current Sense vs ITH Voltage SENSE– Pin Input Bias Current Threshold vs Duty Cycle
80 0 80 5% DUTY CYCLE –50 60 –100 PULSE-SKIPPING MODE –150 TAGE (mV) 60 (μA) 40 –200 Burst Mode OPERATION –250 20 –300 40 CURRENT – –350 0 –400 SENSE –450 FORCED CONTINUOUS MODE 20 –20 –500 CURRENT SENSE THESHOLD (mV) –550 MAXIMUM CURRENT SENSE VOL –40 –600 0 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 0 5 10 15 20 25 0 10 20 30 40 50 60 70 80 90 100 V V ITH (V) SENSE COMMON MODE VOLTAGE (V) DUTY CYCLE (%) 38571 G13 38571 G14 38571 G15
INTVCC and EXTVCC Foldback Current Limit Quiescent Current vs Temperature vs Load Current
90 80 5.20 VIN = 12V 80 75 5.15 TAGE (mV) 70 70 60 65 5.10 50 60 EXTVCC = 0V 40 VOLTAGE (V) 55 CC 5.05 30 INV EXTV 20 QUIESCENT CURRENT (μA) 50 CC = 8.5V 5.00 45 10 MAXIMUM CURRENT SENSE VOL 0 40 4.95 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 –45 –20 5 30 55 80 105 130 0 20 40 60 80 100 120 140 160 180 200 FEEDBACK VOLTAGE (V) TEMPERATURE (°C) LOAD CURRENT (mA) 38571 G17 38571 G18 38571 G16 38571fc 6 Document Outline FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION ELECTRICAL CHARACTERISTICS TYPICAL PERFORMANCE CHARACTERISTICS PIN FUNCTIONS FUNCTIONAL DIAGRAM OPERATION APPLICATIONS INFORMATION TYPICAL APPLICATIONS PACKAGE DESCRIPTION REVISION HISTORY TYPICAL APPLICATION RELATED PARTS