Datasheet LT1072 - 4

LT1072
W U TYPICAL PERFOR A CE CHARACTERISTICS Switch Current Limit vs Duty Cycle Maximum Duty Cycle Flyback Blanking Time
4 96 2.2 95 2.0 3 94 1.8 –55°C 25°C s) µ 2 93 1.6 125°C TIME ( DUTY CYCLE (%) 92 1.4 SWITCH CURRENT (A) 1 91 1.2 0 90 1.0 0 10 20 30 40 50 60 70 80 90 100 –75 –50 –25 0 25 50 75 100 125 150 –75 –50 –25 0 25 50 75 100 125 150 DUTY CYCLE (%) JUNCTION TEMPERATURE (°C) JUNCTION TEMPERATURE (°C) LT1072 • TPC01 LT1072 • TPC02 LT1072 • TPC03
Isolated Mode Flyback Reference Minimum Input Voltage Switch Saturation Voltage Voltage
2.9 1.6 23 2.8 22 SWITCH CURRENT = 1.25A 1.4 150°C R 1.2 21 FEEDBACK = 500Ω 2.7 100°C 1.0 20 25°C 2.6 0.8 19 RFEEDBACK = 1kΩ SWITCH CURRENT = 0A –55°C 0.6 18 2.5 FLYBACK VOLTAGE (V) 0.4 17 RFEEDBACK = 10kΩ MINIMUM INPUT VOLTAGE (V) 2.4 SWITCH SATURATION VOLTAGE (V) 0.2 16 2.3 0 15 –75 –50 –25 0 25 50 75 100 125 150 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 –75 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) SWITCH CURRENT (A) TEMPERATURE (C°) LT1072 • TPC04 LT1072 • TPC05 LT1072 • TPC06
Reference Voltage and Switching Feedback Bias Current vs Line Regulation Frequency vs Temperature Temperature
5 1.250 42 800 4 SWITCHING FREQUENCY 1.248 41 700 3 TJ = 150°C 1.246 40 600 FREQUENCY (kHz) 2 °C T = 25 J 1.244 39 500 1 0 T 1.242 38 400 J = – 55°C REFERENCE VOLTAGE –1 1.240 37 300 – 2 REFERENCE VOLTAGE (V) 1.238 36 200 – 3 FEEDBACK BIAS CURRENT (nA) REFERENCE VOLTAGE CHANGE (mV) 1.236 35 100 – 4 – 5 1.234 34 0 0 10 20 30 40 50 60 –75 –50 –25 0 25 50 75 100 125 150 –75 –50 –25 0 25 50 75 100 125 150 INPUT VOLTAGE (V) TEMPERATURE (°C) TEMPERATURE (°C) LT1072 • TPC07 LT1072 • TPC08 LT1072 • TPC09 1072fc 4