Datasheet LTC7891 (Analog Devices) - 3

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LTC7891 SPECIFICATIONS ELECTRICAL CHARACTERISTICS
TJ = −40°C to +150°C for the minimum and maximum values, TA = 25°C for the typical values, VIN = 12 V, RUN = 12 V, VPRG = floating, EXTVCC = 0 V, DRVSET = 0 V, DRVUV = 0 V, TGUP = TGDN = TGxx, BGUP = BGDN = BGxx, and DTCA and DTCB = 0 V, unless otherwise noted.
Table 1. Electrical Characteristics Parameter Symbol Test Conditions/Comments Min Typ Max Unit
INPUT SUPPLY Input Supply Operating Range VIN 4 100 V Total Input Supply Current in Regulation IVIN 48 V to 5 V, no load1 5 μA 14 V to 3.3 V, no load1 14 μA CONTROLLER OPERATION Regulated Output Voltage Set Point VOUT 0.8 60 V Regulated Feedback Voltage 2 VFB VIN = 4 V to 100 V, ITH voltage = 0.6 V to 1.2 V VPRG = floating, TA = 25°C 0.792 0.8 0.808 V VPRG = floating 0.788 0.8 0.812 V VPRG = 0 V 4.925 5.0 5.075 V VPRG = INTVCC 11.82 12 12.18 V Feedback Current2 VPRG = floating, TA = 25°C −50 0 +50 nA VPRG = 0 V or INTVCC, TA = 25°C 1 2 µA Feedback Overvoltage Threshold Relative to VFB, TA = 25°C 7 10 13 % Transconductance Amplifier2 gM ITH = 1.2 V, sink and source current = 5 μA 1.8 mMho Maximum Current Sense Threshold VSENSE(MAX) VFB = 0.7 V, SENSE− = 3.3 V ILIM = 0 V 21 26 31 mV ILIM = floating 45 50 55 mV ILIM = INTVCC 67 75 83 mV SENSE+ Pin Current ISENSE+ SENSE+ = 3.3 V, TA = 25°C −1 +1 μA SENSE− Pin Current ISENSE− SENSE− < 3 V 1 μA 3.2 V ≤ SENSE– < INTVCC – 0.5 V 75 μA SENSE– > INTVCC + 0.5 V 725 μA Soft Start Charge Current TRACK/SS = 0 V 9.5 12 14.5 μA RUN Pin On Threshold RUN rising 1.15 1.20 1.25 V RUN Pin Hysteresis 120 mV DC SUPPLY CURRENT VIN Shutdown Current RUN = 0 V 1 μA VIN Sleep Mode Current SENSE− < 3.2 V, EXTVCC = 0 V 15 µA Sleep Mode Current3 VIN current, SENSE– ≥ 3.2 V, EXTVCC = 0 V 5 µA VIN current, SENSE– ≥ 3.2 V, EXTVCC ≥ 4.8 V 1 µA EXTVCC current, SENSE– ≥ 3.2 V, EXTVCC ≥ 4.8 V 6 µA SENSE– current, SENSE– ≥ 3.2 V 10 µA Pulse Skipping (PS) or Forced Continuous Mode 2 mA (FCM), VIN or EXTVCC Current3
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Document Outline Features Applications Typical Application Circuit General Description Specifications Electrical Characteristics Absolute Maximum Ratings ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Theory of Operation Functional Diagram Main Control Loop Power and Bias Supplies (VIN, EXTVCC, DRVCC, and INTVCC) High-Side Bootstrap Capacitor Dead Time Control (DTCA and DTCB Pins) Startup and Shutdown (RUN and TRACK/SS Pins) Light Load Operation: Burst Mode Operation, Pulse Skipping Mode, or Forced Continuous Mode (MODE Pin) Frequency Selection, Spread Spectrum, and Phase-Locked Loop (FREQ and PLLIN/SPREAD Pins) Output Overvoltage Protection Foldback Current 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 Pins Tied to GND (Adaptive Dead Time Control) DTCx Pins Tied to INTVCC (Smart Near Zero Dead Time Control) DTCx Pins Connected with a Resistor to GND Power FET Selection CIN and COUT Selection Setting the Output Voltage RUN Pin and Undervoltage Lockout Soft Start and Tracking (TRACK/SS Pin) INTVCC Regulators (OPTI-DRIVE) Topside FET Driver Supply (CB) Minimum On Time Considerations Fault Conditions: Current Limit and Foldback Fault Conditions: Overvoltage Protection Fault Conditions: Overtemperature Protection Phase-Locked Loop and Frequency Synchronization Efficiency Considerations Checking Transient Response Design Example PCB Layout Checklist PCB Layout Debugging Typical Applications Related Products Outline Dimensions Ordering Guide Evaluation Boards Automotive Products