Datasheet LT1372, LT1377 (Analog Devices) - 3

LT1372/LT1377
ELECTRICAL CHARACTERISTICS The
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denotes specifcatons which appy over the full operating temperature range, otherwise specifications are at TA = 25
°
C. VIN = 5V, VC = 0.6V, VFB = VREF, VSW, S/S and NFB pins open, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Maximum Switch Duty Cycle ● 85 95 % Switch Current Limit Blanking Time 130 260 ns BV Output Switch Breakdown Voltage LT1372/LT1377 ● 35 47 V LT1372HV 0°C ≤ TJ ≤ 125°C ● 42 47 V – 40°C ≤ TJ < 0°C (I Grade) 40 V VSAT Output Switch “On” Resistance ISW = 1A ● 0.5 0.8 Ω ILIM Switch Current Limit Duty Cycle = 50% ● 1.5 1.9 2.7 A Duty Cycle = 80% (Note 2) ● 1.3 1.7 2.5 A ∆IIN Supply Current Increase During Switch On-Time 15 25 mA/A ∆ISW Control Voltage to Switch Current 2 A/V Transconductance Minimum Input Voltage ● 2.4 2.7 V IQ Supply Current 2.7V ≤ VIN ≤ 25V ● 4 5.5 mA Shutdown Supply Current 2.7V ≤ VIN ≤ 25V, VS/S ≤ 0.6V 0°C ≤ TJ ≤ 125°C ● 12 30 µA – 40°C ≤ TJ < 0°C (I Grade) 50 µA Shutdown Threshold 2.7V ≤ VIN ≤ 25V ● 0.6 1.3 2 V Shutdown Delay ● 5 12 25 µs S/S Pin Input Current 0V ≤ VS/S ≤ 5V ● – 10 15 µA Synchronization Frequency Range LT1372 ● 600 800 kHz LT1377 ● 1.2 1.6 MHz
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 2:
For duty cycles (DC) between 50% and 90%, minimum of the device may be impaired. guaranteed switch current is given by ILIM = 0.667 (2.75 – DC).
W U TYPICAL PERFORMANCE CHARACTERISTICS Switch Saturation Voltage Switch Current Limit Minimum Input Voltage vs Switch Current vs Duty Cycle vs Temperature
3.0 1.0 3.0 150°C 0.9 100°C 25°C 2.5 2.8 0.8 25°C AND 0.7 2.0 125°C 2.6 0.6 –55°C 1.5 2.4 0.5 –55°C 0.4 1.0 2.2 INPUT VOLTAGE (V) 0.3 SWITCH CURRENT LIMIT (A) 0.2 0.5 2.0 SWITCH SATURATION VOLTAGE (V) 0.1 0 1.8 0 0 10 20 30 40 50 60 70 80 90 100 –50 –25 0 25 50 75 100 125 150 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 DUTY CYCLE (%) TEMPERATURE (°C) SWITCH CURRENT (A) LT1372 • G02 LT1372 • G03 LT1372 • G01 3