Datasheet LT3972 (Analog Devices) - 6

LT3972
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C unless otherwise noted. Error Amp Output Current Minimum Input Voltage Minimum Input Voltage
50 5.0 6.5 40 4.5 30 6.0 20 4.0 10 5.5 0 3.5 –10 5.0 PIN CURRENT (μA) 3.0 C INPUT VOLTAGE (V) INPUT VOLTAGE (V) V –20 V V OUT = 3.3V OUT = 5V –30 2.5 T 4.5 T A = 25°C A = 25°C L = 4.7μH –40 L = 4.7μH f = 800kHz f = 800kHz –50 2.0 4.0 –200 –100 0 100 200 1 10 100 1000 10000 1 10 100 1000 10000 FB PIN ERROR VOLTAGE (mV) LOAD CURRENT (mA) LOAD CURRENT (mA) 3972 G19 3972 G20 3972 G21
Switching Waveforms; VC Voltages Power Good Threshold Burst Mode Operation
2.50 95 2.00 VSW CURRENT LIMIT CLAMP 90 5V/DIV 1.50 85 IL VOLTAGE (V) 0.2A/DIV C 1.00 V SWITCHING THRESHOLD THRESHOLD VOLTAGE (%) 80 V 0.50 OUT 10mV/DIV 0 75 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 VIN = 12V 5μs/DIV 3972 G24 TEMPERATURE (°C) V TEMPERATURE (°C) OUT = 3.3V ILOAD = 10mA 3972 G22 3972 G23
Switching Waveforms; Transition from Burst Mode Operation to Full Switching Waveforms; Full Frequency Frequency Continuous Operation
VSW VSW 5V/DIV 5V/DIV IL IL 0.2A/DIV 0.5A/DIV VOUT VOUT 10mV/DIV 10mV/DIV 3972 G25 VIN = 12V 1μs/DIV 3972 G26 VIN = 12V 1μs/DIV VOUT = 3.3V VOUT = 3.3V ILOAD = 110mA ILOAD = 1A 3972fa 6