LTC7804 ABSOLUTE MAXIMUM RATINGS (Note 1) ITH ... −0.3V to 2V Bias Input Supply Voltage (VBIAS) .. −0.3V to 40V SS, FREQ ... −0.3V to 6V BOOST ... −0.3V to 46V PLLIN/SPREAD, MODE, VFB ... −0.3V to 6V SW ... −5V to 40V BG, TG ... (Note 8) RUN ... −0.3V to 40V Operating Junction Temperature Range (Notes 2, 7) SENSE+, SENSE− ... −0.3V to 40V LTC7804E, LTC7804I ... −40°C to 125°C EXTVCC Voltage ... −0.3V to 30V LTC7804H ... −40°C to 150°C INTVCC, (BOOST-SW) .. −0.3V to 6V Storage Temperature Range .. −65°C to 150°C PIN CONFIGURATION TOP VIEW CC BOOST BG V BIAS EXTV TOP VIEW 16 15 14 13 SS 1 16 SW SENSE– 2 15 TG TG 1 12 INTVCC SENSE+ 3 14 BOOST SW 2 17 11 MODE V 4 FB 17 13 BG ITH 5 GND GND 12 V SS PLLIN/SPREAD BIAS 3 10 RUN 6 11 EXTVCC SENSE– 4 9 FREQ FREQ 7 10 INTVCC PLLIN/SPREAD 8 9 MODE 5 6 7 8 MSE PACKAGE + V FB ITH 16-LEAD PLASTIC MSOP RUN TJMAX = 125°C, θJA = 40°C/W, θJC = 10°C/W SENSE EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB UD PACKAGE 16-LEAD (3mm × 3mm) PLASTIC QFN TJMAX = 125°C, θJA = 68°C/W, θJC = 4.2°C/W EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB Rev. 0 For more information www.analog.com 3 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Main Control Loop INTVCC/EXTVCC Power Boost Supply and Dropout (BOOST and SW Pins) Shutdown and Start-Up (RUN, SS Pins) Light Load Current Operation: Burst Mode Operation, Pulse-Skipping or Forced Continuous Mode (MODE Pin) Frequency Selection, Spread Spectrum and Phase-Locked-Loop (FREQ and PLLIN/SPREAD Pins) Operation When VIN > VOUT Operation at Low Input Voltage BOOST Supply Refresh and Internal Charge Pump Applications Information SENSE+ and SENSE– Pins Low Value Resistor Current Sensing Inductor DCR Sensing Inductor Value Calculation Inductor Core Selection Power MOSFET Selection CIN and COUT Selection Setting Output Voltage RUN Pin Soft-Start (SS Pin) INTVCC Regulators Topside MOSFET Driver Supply (CB, DB) Phase-Locked Loop and Frequency Synchronization Setting the Operating Frequency Selecting the Light-Load Operating Mode Minimum On-Time Considerations Fault Conditions: Overtemperature Protection Efficiency Considerations Checking Transient Response Design Example PC Board Layout Checklist PC Board Layout Debugging Package Description Typical Application Related Parts