Datasheet LT1939 (Analog Devices) - 4

LT1939
TYPICAL PERFORMANCE CHARACTERISTICS Shutdown Threshold and Minimum Feedback Voltage vs Temperature RT/SYNC Voltage vs Temperature Input Voltage vs Temperature
0.820 1.10 3.0 1.08 0.815 MINIMUM INPUT VOLTAGE 2.5 1.06 0.810 RRT/SYNC = 90.9k 1.04 2.0 0.805 1.02 FB 1.5 TAGE (V) 0.800 1.00 VOL LFB 0.795 VOLTAGE (V) 0.98 VOLTAGE (V) 1.0 0.96 SHUTDOWN THRESHOLD 0.790 RRT/SYNC = 15k 0.94 0.5 0.785 0.92 0.780 0.90 0 –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 (°C) TEMPERATURE (°C) TEMPERATURE (°C) 1939 G01 1939 G02 1939 G03
Shutdown Pin Currents vs Shutdown Quiescent Current vs Temperature Temperature Error Amplifi er gm vs Temperature
6 15.0 400 5 12.5 350 VSHDN = 0.9V 4 10.0 300 3 7.5 250 VSHDN = 0.7V CURRENT (μA) CURRENT (μA) 2 5.0 200 1 2.5 TRANSCONDUCTANCE (μmhos) 150 0 0 100 –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 (°C) TEMPERATURE (°C) TEMPERATURE (°C) 1939 G04 1939 G05 1939 G06
Soft-Start Source Current vs Soft-Start Feedback Offset vs VC Switching Threshold vs Temperature Temperature Temperature
3.5 150 0.95 3.3 0.90 3.1 125 0.85 2.9 LFB 0.80 2.7 0.75 2.5 100 0.70 2.3 CURRENT (μA) VOLTAGE (mV) FB VOLTAGE (V) 0.65 2.1 75 1.9 0.60 1.7 0.55 1.5 50 0.50 –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 (°C) TEMPERATURE (°C) TEMPERATURE (°C) 1939 G07 1939 G08 1939 G09 1939f 4