link to page 7 link to page 7 link to page 7 Data SheetLTC7893SPECIFICATIONS Table 1. Electrical Characteristics (Specifications are at TJ = -40°C to +125°C for the minimum and maximum values, TA = 25°C for the typical values, VBIAS = 12V, RUN = 5V, VPRG = Floating, EXTVCC = 0V, DRVSET = 0V, DRVUV = 0V, DTCA and DTCB = 0V, unless otherwise noted.) PARAMETERSYMBOLCONDITIONS/COMMENTSMINTYPMAXUNITSInput Supply Bias Input Supply V Operating Range BIAS 4 100 V Boost Converter Input Supply Operating VIN VBIAS ≥ 4V 1 60 V Range Output Voltage V Operating Range OUT 1.2 100 V Controller Operation VBIAS = 4V to 100V, ITH Voltage = 0.6V to 1.2V Regulated Feedback VPRG = floating, T V A = 25°C 1.188 1.2 1.212 V Voltage 1 FB VPRG = floating 1.182 1.2 1.218 V VPRG = 0V 23.45 24 24.55 V VPRG = INTVCC 27.38 28 28.62 V VPRG = floating, T -50 0 +50 nA Feedback Current 1 A= 25°C VPRG = 0V or INTVCC 2 µA Feedback Overvoltage Relative to V Threshold FB, TA = 25°C 7 10 13 % Transconductance g 1.8 mMho Amplifier 1 m ITH = 1.2V, Sink and Source Current = 5µA VFB = 1.1V, SENSE+ = 12V Maximum Current V ILIM = 0V 21 26 32 mV Sense Threshold SENSE(MAX) ILIM = floating 45 50 56 mV ILIM = INTVCC 67 75 83 mV SENSE- Pin Current ISENSE- SENSE- = 12V, TA = 25°C -1 +1 µA SENSE+ < 3V 1 µA SENSE+ Pin Current I SENSE+ 3.3V ≤ SENSE+ < INTVCC – 0.5V 75 µA SENSE+ > INTVCC + 0.5V 725 µA Soft-Start Charge SS = 0V 9.5 12 14.5 µA Current analog.com Rev. 0 4 of 48 Document Outline Features Applications General Description Typical Application TABLE OF CONTENTS Revision History Specifications Absolute Maximum Ratings Pin Configurations and Function Descriptions Typical Performance Characteristics Functional diagram Theory of Operation Main Control Loop Power and Bias Supplies (VBIAS, EXTVCC, DRVCC, and INTVCC) High-Side Bootstrap Capacitor Dead Time Control (DTCA and DTCB Pins) Startup and Shutdown (RUN and SS Pins) Light Load 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) Output Overvoltage Protection Power Good Applications Information Inductor Value Calculation Inductor Core Selection Current Sense Selection Low Value Resistor Current Sensing Inductor DCR Current Sensing Setting the Operating Frequency Selecting the Light-Load Operating Mode Dead Time Control (DTCA and DTCB Pins) DTCx Pin Tied to Ground (Adaptive Dead Time Control) DTCx Pin connected with a resistor to GND Power FET Selection CIN and COUT Selection Setting the Output Voltage RUN Pin and Undervoltage Lockout Soft-Start (SS Pin) INTVCC Regulators (OPTI-DRIVE) Topside FET Driver Supply (CB) Minimum On-Time Considerations Fault Conditions: Overtemperature Protection Phase-Locked Loop and Frequency Synchronization Efficiency Considerations Checking Transient Response Design Example PCB Board Layout Checklist PCB Layout Debugging Typical Applications Related Parts Outline Dimensions Ordering Guide