LTC3703 elecTrical characTerisTics Note 1: Stresses beyond those listed under Absolute Maximum Ratings Note 5: The dynamic input supply current is higher due to the power may cause permanent damage to the device. Exposure to any Absolute MOSFET gate charge being delivered at the switching frequency (QG • fOSC). Maximum Rating condition for extended periods may affect device Note 6: Guaranteed by design. Not subject to test. reliability and lifetime. Note 7: This IC includes overtemperature protection that is intended Note 2: The LTC3703E is guaranteed to meet performance specifications from to protect the device during momentary overload conditions. Junction 0°C to 85°C. Specifications over the –40°C to 85°C operating temperature temperature will exceed 125°C when overtemperature protection is active. range are assured by design, characterization and correlation with statistical Continuous operation above the specified maximum operating junction process controls. The LTC3703I is guaranteed over the full –40°C to 125°C temperature may impair device reliability. operating junction temperature range. The LTC3703H is guaranteed over the Note 8: R full –40°C to 150°C operating junction temperature range. DS(ON) guaranteed by correlation to wafer level measurement. Note 9: High junction temperatures degrade operating lifetimes. Operating Note 3: TJ is calculated from the ambient temperature TA and power lifetime at junction temperatures greater than 125°C is derated to 1000 hours. dissipation PD according to the following formula: Note 10: Transient voltages (such as due to inductive ringing) are allowed LTC3703: TJ = TA + (PD • 100 °C/W) G Package beyond this range provided that the voltage does not exceed 10V below Note 4: The LTC3703 is tested in a feedback loop that servos VFB to the ground and duration does not exceed 20ns per switching cycle. reference voltage with the COMP pin forced to a voltage between 1V and 2V. Typical perForMance characTerisTics TA = 25°C unless otherwise noted.Efficiency vs Input VoltageEfficiency vs Load CurrentLoad Transient Response 100 100 I 95 OUT = 5A 95 VOUT VIN = 15V 50mV/DIV 90 90 VIN = 45V IOUT = 0.5A 85 85 VIN = 75V IOUT 2A/DIV EFFICIENCY (%) 80 EFFICIENCY (%) 80 75 VOUT = 12V 75 VOUT = 5V 3703 G03 VIN = 50V 50µs/DIV f = 300kHz f = 250kHz VOUT = 12V PULSE SKIP DISABLED PULSE SKIP ENABLED 1A TO 5A LOAD STEP 70 70 0 10 20 30 40 50 60 70 80 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 INPUT VOLTAGE (V) LOAD CURRENT (A) 3703 G01 3703 G02 VCC Shutdown Current vsVCC Current vs VCC VoltageVCC Current vs TemperatureVCC Voltage 3.5 4 100 90 3.0 COMP = 1.5V 80 3 COMP = 1.5V 2.5 70 2.0 60 V 2 50 FB = 0V 1.5 CURRENT (mA) CURRENT (mA) VFB = 0V CURRENT (µA) 40 V CC 1.0 V CC V CC 30 1 20 0.5 10 0 0 0 6 8 10 12 14 16 –50 –25 0 25 50 75 100 125 150 6 8 10 12 14 16 VCC VOLTAGE (V) TEMPERATURE (°C) VCC VOLTAGE (V) 3703 G04 3703 G05 3703 G06 3703fc 4 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts