Datasheet LT3995 (Analog Devices) - 7

LT3995
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. Burst Frequency SS Pin Current Boost Capacitor Charger
600 2.6 160 VIN = 12V VSS = 0.5V VBST = VIN 140 500 2.4 VOUT = 5V fSW = 500kHz 2.2 120 400 L = 10µH 2.0 100 300 1.8 80 VOUT = 3.3V 1.6 60 200 fSW = 300kHz L = 8.2µH SS PIN CURRENT (µA) 1.4 OUT PIN CURRENT (mA) 40 SWITCHING FREQUENCY (kHz) 100 1.2 20 50 1.0 0 0 20 40 60 80 100 120 –55 –25 5 35 65 95 125 155 0 2 4 6 8 10 12 14 16 LOAD CURRENT (mA) TEMPERATURE (°C) OUT PIN VOLTAGE (V) 3995 G27 3995 G28 3995 G29
Boost Diode Forward Voltage Dropout Comparator Thresholds Dropout Performance
1.8 600 VIN 2V/DIV VIN 1.6 580 VOUT 1.4 560 VOUT 540 1.2 2V/DIV VOUT RISING 520 1.0 500 0.8 480 0.6 VOUT FALLING 3995 G32 460 1kΩ LOAD 100ms/DIV BOOST DIODE VOLTAGE (V) (12mA IN REGULATION) 0.4 DROPOUT THRESHOLD (mV) 440 0.2 420 0 400 0 0.5 1 1.5 2 –55 –25 5 35 65 95 125 155 BOOST DIODE CURRENT (A) TEMPERATURE (°C) 3995 G30 3995 G31
Full Frequency Switching Dropout Switching Burst Mode Switching Waveforms Waveforms Waveforms
VSW VSW VSW 20V/DIV 20V/DIV 2V/DIV IL I I L 1A/DIV L 1A/DIV 1A/DIV VOUT VOUT VOUT 50mV/DIV 50mV/DIV 50mV/DIV V 3995 G33 3995 G34 3995 G35 IN = 48V 5µs/DIV VIN = 48V 2µs/DIV VIN = 5V 5µs/DIV VOUT = 3.3V VOUT = 3.3V VOUT SET FOR 5V ILOAD = 70mA ILOAD = 1A ILOAD = 0.3A COUT = 47µF COUT = 47µF COUT = 47µF 3995f For more information www.linear.com/LT3995 7 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts