Datasheet LTC7890 (Analog Devices) - 4

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LTC7890 SPECIFICATIONS Table 1. Electrical Characteristics (Continued) Parameter Symbol Test Conditions/Comments Min Typ Max Unit
Sleep Mode Current3, Both Channels On SENSE1– ≥ 3.2 V, EXTVCC ≥ 4.8 V VIN Current 1 µA EXTVCC Current 7 µA SENSE1– Current 12 µA Pulse Skipping (PS) or Forced Continuous Mode (FCM), VIN or EXTVCC Current3 One Channel On 2 mA Both Channels On 3 mA GATE DRIVERS TGxxx or BGxxx On Resistance DRVSET = INTVCC Pull-Up 2.0 Ω Pull-Down 1.0 Ω BOOSTx to DRVCC Switch On Resistance DRVSET = INTVCC 7 Ω TGxxx or BGxxx Transition Time4 Rise Time 25 ns Fall Time 15 ns TGxxx Off to BGxxx On Delay4 DTCA = 0 V Synchronous Switch On Delay Time 20 ns BGxxx Off to TGxxx On Delay4 DTCB = 0 V Top Switch On Delay Time 20 ns BGxxx Falling to SWx Rising Delay5 DTCB = INTVCC or resistor DTCA = INTVCC 2 ns DTCA = 50 kΩ 25 ns DTCA = 100 kΩ 40 ns SWx Falling to BGxxx Rising Delay5 DTCA = INTVCC or resistor DTCB = INTVCC 0.5 ns DTCB = 50 kΩ 25 ns DTCB = 100 kΩ 40 ns TGxxx Minimum On-Time6 tON(MIN) 40 ns Maximum Duty Cycle Output in dropout, FREQ = 0 V 99 % LOW DROPOUT (LDO) LINEAR REGULATORS INTVCC Voltage for VIN and EXTVCC LDOs EXTVCC = 0 V for VIN LDO, 12 V for EXTVCC LDO DRVSET = INTVCC 5.2 5.5 5.7 V DRVSET = 0 V 4.8 5.0 5.2 V DRVSET= 64.9 kΩ 4.5 4.75 5.0 V DRVCC Load Regulation DRVCC load current = 0 mA to 100 mA, TA = 25°C 1 3 % Undervoltage Lockout UVLO DRVCC Rising DRVUV = INTVCC 4.8 5.0 5.2 V DRVUV = 0 V 3.6 3.8 4.0 V DRVUV = floating 4.2 4.4 4.6 V DRVCC Falling DRVUV = INTVCC 4.55 4.75 4.95 V DRVUV = 0 V 3.4 3.6 3.8 V DRVUV = floating 4.0 4.18 4.4 V EXTVCC LDO Switchover Voltage EXTVCC Rising DRVUV = INTVCC or floating, TA = 25°C 5.75 5.95 6.15 V DRVUV = 0 V, TA = 25°C 4.6 4.76 4.9 V EXTVCC Switchover Hysteresis EXTVCC Falling DRVUV = INTVCC or floating 390 mV DRVUV = 0 V 220 mV
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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 (RUNx and TRACK/SSx 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 RUNx Pins and Undervoltage Lockout Soft Start and Tracking (TRACK/SSx Pin) 2-Phase Single Output Operation 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