Datasheet LT3991, LT3991-3.3, LT3991-5 (Analog Devices) - 5

LT3991/LT3991-3.3/LT3991-5
Typical perForMance characTerisTics TA = 25°C, unless otherwise noted. Maximum Load Current Maximum Load Current Load Regulation
3.0 2.5 0.30 VOUT = 3.3V VOUT = 5V 0.25 REFERENCED FROM VOUT AT 0.5A LOAD 2.5 2.0 0.20 0.15 TYPICAL 2.0 TYPICAL 0.10 1.5 MINIMUM TION (%) 0.05 1.5 MINIMUM 0 1.0 –0.05 LOAD CURRENT (A) 1.0 LOAD CURRENT (A) –0.10 LOAD REGULA –0.15 0.5 0.5 –0.20 –0.25 0 0 –0.30 5 10 15 20 25 30 35 40 45 50 55 5 10 15 20 25 30 35 40 45 50 55 0 200 400 600 800 1000 1200 INPUT VOLTAGE (V) INPUT VOLTAGE (V) LOAD CURRENT (mA) 3991 G08 3991 G09 3991 G10
Switching Frequency Switch Current Limit Switch Current Limit
1000 3.0 2.5 950 2.4 2.5 2.3 900 2.0 2.2 850 2.1 800 1.5 2.0 750 1.9 FREQUENCY (kHz) 1.0 1.8 700 SWITCH CURRENT LIMIT (A) SWITCH CURRENT LIMIT (A) 0.5 1.7 650 1.6 DUTY CYCLE = 30% 600 0 1.5 –55 –25 5 35 65 95 125 155 0 20 40 60 80 100 –55 –25 5 35 65 95 125 155 TEMPERATURE (°C) DUTY CYCLE (%) TEMPERATURE (°C) 3991 G11 3991 G12 3991 G13
Switch VCESAT Boost Pin Current LT3991 Frequency Foldback
700 45 900 800 600 40 35 700 500 30 600 400 (mV) 25 500 T 300 20 400 V CESA 15 300 200 BOOST PIN CURRENT (mA) 10 SWITCHING FREQUENCY (kHz) 200 100 5 100 0 0 0 0 250 500 750 1000 1250 1500 0 250 500 750 1000 1250 1500 0 0.2 0.4 0.6 0.8 1 1.2 SWITCH CURRENT (mA) SWITCH CURRENT (mA) FB PIN VOLTAGE (V) 3991 G14 3991 G15 3991 G16 3991fa 5 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Related Parts