LTC1871-7 elecTrical characTerisTicsThe l denotes the specifications which apply over the full operatingtemperature range, otherwise specifications are at TA = 25°C. VIN = 8V, VRUN = 1.5V, RFREQ = 80k, VMODE/SYNC = 0V, unless otherwise specified. SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITS UVLO INTVCC Undervoltage Lockout Threshold Rising INTVCC 5.6 V Falling INTVCC 4.6 V UVLO Hysteresis 1.0 V ∆VINTVCC INTVCC Regulator Line Regulation 8V ≤ VIN ≤ 15V 8 25 mV ∆VIN1 ∆VINTVCC INTVCC Regulator Line Regulation 15V ≤ VIN ≤ 30V 70 200 mV ∆VIN2 VLDO(LOAD) INTVCC Load Regulation 0 ≤ IINTVCC ≤ 20mA, VIN = 8V –2 –0.2 % VDROPOUT INTVCC Regulator Dropout Voltage VIN = 6V, INTVCC Load = 20mA 280 mV GATE Driver tr GATE Driver Output Rise Time CL = 3300pF (Note 7) 17 100 ns tf GATE Driver Output Fall Time CL = 3300pF (Note 7) 8 100 ns Note 1: Stresses beyond those listed under Absolute Maximum Ratings Note 4: The dynamic input supply current is higher due to power MOSFET may cause permanent damage to the device. Exposure to any Absolute gate charging (QG • fOSC). See Applications Information. Maximum Rating condition for extended periods may affect device Note 5: The LTC1871-7 is tested in a feedback loop that servos VFB to the reliability and lifetime. reference voltage with the ITH pin forced to a voltage between 0V and 1.4V Note 2: The LTC1871E-7 is guaranteed to meet performance specifications (the no load to full load operating voltage range for the ITH pin is 0.3V to from 0°C to 70°C junction temperature. Specifications over the –40°C 1.23V). to 85°C operating junction temperature range are assured by design, Note 6: In a synchronized application, the internal slope compensation characterization and correlation with statistical process controls. The gain is increased by 25%. Synchronizing to a significantly higher ratio will LTC1871I-7 is guaranteed over the full –40°C to 125°C operating junction reduce the effective amount of slope compensation, which could result in temperature range. subharmonic oscillation for duty cycles greater than 50%. Note 3: TJ is calculated from the ambient temperature TA and power Note 7: Rise and fall times are measured at 10% and 90% levels. dissipation PD according to the following formula: TJ = TA + (PD • 120°C/W) Typical perForMance characTerisTicsFB Voltage vs TempFB Voltage Line RegulationFB Pin Current vs Temperature 1.25 1.231 60 50 1.24 40 1.23 1.230 30 FB VOLTAGE (V) FB VOLTAGE (V) 20 FB PIN CURRENT (nA) 1.22 10 1.21 1.229 0 –50 –25 0 25 50 75 100 125 150 0 5 10 15 20 25 30 35 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) VIN (V) TEMPERATURE (°C) 18717 G01 18717 G02 18717 G03 18717fd 4 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts