Datasheet LT1976, LT1976B (Analog Devices) - 6

LT1976/LT1976B
W U TYPICAL PERFOR A CE CHARACTERISTICS PGFB Threshold PG Sink Current Switch Peak Current Limit
1.20 250 3.5 1.18 1.16 200 3.0 1.14 1.12 μA) 150 1.10 2.5 VOLTAGE (V) 1.08 100 CURRENT ( 1.06 2.0 PEAK SWITCH CURRENT (A) 1.04 50 1.02 1.00 0 1.5 –50 –25 0 25 50 75 100 125 150 –50 –25 0 25 50 75 100 125 150 –50 –25 –0 25 50 75 100 125 150 TEMPERATURE ( TEMPERATURE ( TEMPERATURE ( °C) °C) °C) 1976 G08 1976 G08 1976 G10
Soft-Start Current Threshold Oscillator Frequency vs FB Voltage vs FB Voltage Switch On Voltage (VCESAT)
50 250 500 TJ = 25°C TJ = 25°C 45 450 40 200 400 35 350 SOFT-START μA) 30 DEFEATED 150 300 TJ = 125°C 25 250 20 100 200 CURRENT ( VOLTAGE (mV) TJ = 25°C 15 FREQUENCY (kHz) 150 10 50 100 TJ = –50°C 5 50 0 0 0 0 0.2 0.4 0.6 0.8 1.0 1.2 0 0.2 0.4 0.6 0.8 1.0 1.2 0.5 0.7 0.9 1.1 1.3 1.5 FB VOLTAGE (V) FB VOLTAGE (V) LOAD CURRENT (A) 1976 G11 1976 G12 1976 G13
LT1976 Supply Current LT1976 Burst Mode Threshold vs Input Voltage Minimum Input Voltage vs Input Voltage
150 7.5 200 VOUT = 3.3V VOUT = 3.3V TA = 25°C 7.0 180 L = 33μH 125 C 6.5 160 OUT = 100μF 5V START μA) 140 100 6.0 120 5.5 75 5V RUNNING 100 5.0 3.3V START 80 50 INPUT VOLTAGE (V) 4.5 LOAD CURRENT (mA) 60 SUPPLY CURRENT ( 4.0 40 25 3.5 3.3V RUNNING 20 0 3.0 0 0 10 20 30 40 50 60 0 200 400 600 800 1000 1200 1400 1600 5 7 9 11 13 15 17 19 21 23 25 INPUT VOLTAGE (V) LOAD CURRENT (mA) 1976 F05 INPUT VOLTAGE (V) 1976 G19 1975 G20 1976bfg 6