Datasheet LTC3780 (Analog Devices) - 4

LTC3780
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating junction temperature range, otherwise specifications are at TA = 25°C. (Note 7) VIN = 15V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
DF MAX, Boost Maximum Duty Factor % Switch C On 99 % DF MAX, Buck Maximum Duty Factor % Switch A On (in Dropout) 99 % VRUN(ON) RUN Pin On Threshold VRUN Rising 1 1.5 2 V ISS Soft-Start Charge Current VRUN = 2V 0.5 1.2 µA VSENSE(MAX) Maximum Current Sense Threshold Boost: VOSENSE = VREF – 50mV l 120 160 185 mV Buck: VOSENSE = VREF – 50mV l –95 –110 –150 mV VSENSE(MIN,BUCK) Minimum Current Sense Threshold Discontinuous Mode –6 mV TG1, TG2 tr TG Rise Time CLOAD = 3300pF (Note 5) 50 ns TG1, TG2 tf TG Fall Time CLOAD = 3300pF (Note 5) 45 ns BG1, BG2 tr BG Rise Time CLOAD = 3300pF (Note 5) 45 ns BG1, BG2 tf BG Fall Time CLOAD = 3300pF (Note 5) 55 ns TG1/BG1 t1D TG1 Off to BG1 On Delay, CLOAD = 3300pF Each Driver 80 ns Switch C On Delay BG1/TG1 t2D BG1 Off to TG1 On Delay, CLOAD = 3300pF Each Driver 80 ns Synchronous Switch D On Delay TG2/BG2 t3D TG2 Off to BG2 On Delay, CLOAD = 3300pF Each Driver 80 ns Synchronous Switch B On Delay BG2/TG2 t4D BG2 Off to TG2 On Delay, CLOAD = 3300pF Each Driver 80 ns Switch A On Delay Mode BG1 Off to BG2 On Delay, CLOAD = 3300pF Each Driver 250 ns Transition 1 Switch A On Delay Mode BG2 Off to BG1 On Delay, CLOAD = 3300pF Each Driver 250 ns Transition 2 Synchronous Switch D On Delay tON(MIN,BOOST) Minimum On-Time for Main Switch in Switch C (Note 6) 200 ns Boost Operation tON(MIN,BUCK) Minimum On-Time for Synchronous Switch B (Note 6) 180 ns Switch in Buck Operation
Internal VCC Regulator
VINTVCC Internal VCC Voltage 7V < VIN < 30V, VEXTVCC = 5V l 5.7 6 6.3 V ∆VLDO(LOADREG) Internal VCC Load Regulation ICC = 0mA to 20mA, VEXTVCC = 5V 0.2 2 % VEXTVCC EXTVCC Switchover Voltage ICC = 20mA, VEXTVCC Rising l 5.4 5.7 V ∆VEXTVCC(HYS) EXTVCC Switchover Hysteresis 300 mV ∆VEXTVCC EXTVCC Switch Drop Voltage ICC = 20mA, VEXTVCC = 6V 150 300 mV
Oscillator and Phase-Locked Loop
fNOM Nominal Frequency VPLLFLTR = 1.2V 260 300 330 kHz fLOW Lowest Frequency VPLLFLTR = 0V 170 200 220 kHz fHIGH Highest Frequency VPLLFLTR = 2.4V 340 400 440 kHz RPLLIN PLLIN Input Resistance 50 kΩ IPLLLPF Phase Detector Output Current fPLLIN < fOSC –15 µA fPLLIN > fOSC (Note 9) 15 µA Rev G 4 For more information www.analog.com Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Block Diagram Operation Applications Information Typical Application Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Revision History Typical Application Related Parts