Datasheet LT3971A, LT3971A-5 (Analog Devices) - 6

LT3971A/LT3971A-5
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. Minimum Switch On-Time/ Switch Off-Time Soft-Start Minimum Input Voltage
400 2.5 5.0 VOUT = 3.3V 350 4.8 2.0 4.6 300 4.4 MIN T 250 OFF 1A LOAD 1.5 4.2 TO START TAGE (V) 200 MIN T 4.0 OFF 0.5A LOAD 150 1.0 3.8 TO RUN INPUT VOL 3.6 SWITCH ON/OFF TIME (ns) 100 MIN T SWITCH CURRENT LIMIT (A) 0.5 3.4 ON 50 3.2 0 0 3.0 –55 –25 5 35 65 95 125 155 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 0 200 400 600 800 1000 1200 TEMPERATURE (°C) SS PIN VOLTAGE (V) LOAD CURRENT (mA) 3971A G19 3971A G20 3971A G21
Minimum Input Voltage EN Threshold Boost Diode Forward Voltage
6.4 1.05 1.6 VOUT = 5V 1.04 6.2 1.4 1.03 1.2 6.0 1.02 TO START TAGE (V) RISING THRESHOLD 1.01 1.0 5.8 TAGE (V) 1.00 0.8 5.6 0.99 0.6 INPUT VOL FALLING THRESHOLD 5.4 0.98 BOOST DIODE VF (V) THRESHOLD VOL 0.4 0.97 5.2 TO RUN 0.96 0.2 5.0 0.95 0 0 200 400 600 800 1000 1200 –55 –25 5 35 65 95 125 155 0 250 500 750 1000 1250 1500 LOAD CURRENT (mA) TEMPERATURE (°C) BOOST DIODE CURRENT (mA) 3971A G22 3971A G23 3971A G24
Transient Load Response, Transient Load Response, Load Current Stepped from 25mA Load Current Stepped from Power Good Threshold (Burst Mode Operation) to 525mA 0.5A to 1A
95 94 93 V V OUT OUT 100mV/ 92 100mV/DIV DIV TAGE (%) 91 90 89 88 IL THRESHOLD VOL 500mA/ 87 DIV IL 86 500mA/DIV 85–55 –25 5 35 65 95 125 155 10μs/DIV 3971A G26 10μs/DIV 3971A G27 TEMPERATURE (°C) VIN = 12V, VOUT = 3.3V VIN = 12V, VOUT = 3.3V 3971A G25 COUT = 47μF COUT = 47μF 3971af 6 Document Outline FEATURES DESCRIPTION APPLICATIONS 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 TYPICAL APPLICATION RELATED PARTS