Datasheet LT3971, LT3971-3.3, LT3971-5 (Analog Devices) - 6

LT3971/LT3971-3.3/LT3971-5
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. Switch VCESAT Boost Pin Current Frequency Foldback
600 30 900 800 500 25 700 400 20 600 500 (mV) T 300 15 400 V CESA 200 10 300 BOOST PIN CURRENT (mA) 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) 3971 G16 3971 G14 3971 G15
Minimum Switch On-Time/ LT3971-X Frequency Foldback Switch Off-Time Soft-Start
900 400 2.5 800 350 2.0 700 300 600 250 MIN TOFF 1A LOAD 1.5 500 200 MIN T 400 OFF 0.5A LOAD 1.0 150 300 200 SWITCH ON/OFF TIME (ns) 100 SWITCH CURRENT LIMIT (A) SWITCHING FREQUENCY (kHz) 0.5 MIN TON 100 50 0 0 0 0 20 40 60 80 100 –55 –25 5 35 65 95 125 155 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 V TEMPERATURE (°C) SS PIN VOLTAGE (V) OUT (% OF REGULATION VOLTAGE)3971 G30 3971 G17 3971 G18
Minimum Input Voltage Minimum Input Voltage EN Threshold
5.0 6.4 1.05 VOUT = 3.3V VOUT = 5V 4.8 1.04 6.2 4.6 1.03 4.4 6.0 1.02 TO START 4.2 TAGE (V) TO START 1.01 RISING THRESHOLD 5.8 TAGE (V) TAGE (V) 4.0 1.00 3.8 5.6 0.99 TO RUN INPUT VOL 3.6 INPUT VOL 5.4 0.98 FALLING THRESHOLD THRESHOLD VOL 3.4 0.97 5.2 TO RUN 3.2 0.96 3.0 5.0 0.95 0 200 400 600 800 1000 1200 0 200 400 600 800 1000 1200 –55 –25 5 35 65 95 125 155 LOAD CURRENT (mA) LOAD CURRENT (mA) TEMPERATURE (°C) 3971 G19 3971 G20 3971 G21 3971fd 6 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