Datasheet LT3681 (Analog Devices) - 5

LT3681
W U TYPICAL PERFOR A CE CHARACTERISTICS TA = 25°C unless otherwise noted. Switch Voltage Drop Boost Pin Current Feedback Voltage
700 90 1.290 80 600 1.285 70 1.280 500 60 1.275 400 50 1.270 300 40 1.265 30 VOLTAGE DROP (mV) 200 FEEDBACK VOLTAGE (V) BOOST PIN CURRENT (mA) 20 1.260 100 10 1.255 0 0 1.250 0 500 1000 1500 2000 2500 3000 3500 0 500 1000 1500 2000 2500 3000 3500 –50 –25 0 25 50 75 100 125 SWITCH CURRENT (mA) SWITCH CURRENT (mA) TEMPERATURE (°C) 3681 G10 3681 G11 4681 G12
Switching Frequency Frequency Foldback Minimum Switch On-Time
1.20 1200 140 RT = 45.3kΩ RT = 45.3kΩ 1.15 120 1000 1.10 100 800 1.05 80 1.00 600 60 0.95 FREQUENCY (MHz) 400 40 0.90 SWITCHING FREQUENCY (kHz) 200 MINIMUM SWITCH ON TIME (ns) 0.85 20 0.80 0 0 –50 –25 0 25 50 75 100 125 0 200 400 600 800 1000 1200 1400 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) FB PIN VOLTAGE (mV) TEMPERATURE (˚C) 4681 G13 3681 G14 3681 G15
Soft Start RUN/SS Pin Current Boost Diode
4.0 12 1.6 3.5 1.4 10 3.0 µA) 1.2 8 (V) f 2.5 1.0 2.0 6 0.8 1.5 0.6 4 BOOST DIODE V 1.0 0.4 RUN/SS PIN CURRENT ( SWITCH CURRENT LIMIT (A) 2 0.5 0.2 0 0 0 0 0.5 1 1.5 2 2.5 3 3.5 0 5 10 15 20 25 30 35 0 0.5 1.0 1.5 2.0 RUN/SS PIN VOLTAGE (V) RUN/SS PIN VOLTAGE (V) BOOST DIODE CURRENT (A) 3681 G16 3681 G17 3681 G18 3681f 5