Datasheet LTC7890 (Analog Devices) - 2
| Fabricante | Analog Devices |
| Descripción | Low IQ, Dual, 2-Phase Synchronous Step-Down Controller for GaN FETs in 40-Lead QFN (6mm x 6mm, Plastic Side Wettable) package |
| Páginas / Página | 41 / 2 — LTC7890. TABLE OF CONTENTS. REVISION HISTORY. 4/2023—Revision 0: Initial … |
| Formato / tamaño de archivo | PDF / 1.9 Mb |
| Idioma del documento | Inglés |
LTC7890. TABLE OF CONTENTS. REVISION HISTORY. 4/2023—Revision 0: Initial Version. analog.com. Rev. 0 | 2 of 41
Línea de modelo para esta hoja de datos
Versión de texto del documento
link to page 1 link to page 1 link to page 1 link to page 1 link to page 3 link to page 3 link to page 6 link to page 6 link to page 7 link to page 10 link to page 16 link to page 16 link to page 16 link to page 16 link to page 16 link to page 17 link to page 17 link to page 17 link to page 17 link to page 18 link to page 18 link to page 18 link to page 18 link to page 18 link to page 18 link to page 19 link to page 19 link to page 19 link to page 20 link to page 20 link to page 20 link to page 20 link to page 21 link to page 21 link to page 22 link to page 22 link to page 23 link to page 24 link to page 25 link to page 26 link to page 26 link to page 26 link to page 27 link to page 27 link to page 29 link to page 29 link to page 29 link to page 29 link to page 29 link to page 29 link to page 29 link to page 29 link to page 30 link to page 30 link to page 31 link to page 32 link to page 34 link to page 35 link to page 39 link to page 40 link to page 40 link to page 41 Data Sheet
LTC7890 TABLE OF CONTENTS
Features.. 1 Current Sense Selection.. 20 Applications... 1 Low Value Resistor Current Sensing..21 Typical Application Circuit ...1 Inductor DCR Current Sensing...21 General Description...1 Setting the Operating Frequency... 22 Specifications.. 3 Selecting the Light Load Operating Mode..22 Electrical Characteristics.. 3 Dead Time Control (DTCA and DTCB Pins).. 23 Absolute Maximum Ratings...6 Power FET Selection..24 ESD Caution...6 CIN and COUT Selection..25 Pin Configuration and Function Descriptions.. 7 Setting the Output Voltage... 26 Typical Performance Characteristics... 10 RUNx Pins and Undervoltage Lockout...26 Theory of Operation...16 Soft Start and Tracking (TRACK/SSx Pin)... 26 Functional Diagram.. 16 2-Phase Single Output Operation.. 27 Main Control Loop..16 INTVCC Regulators (OPTI-DRIVE)...27 Power and Bias Supplies (VIN, EXTVCC, Topside FET Driver Supply (CB)...29 DRVCC, and INTVCC)..16 Minimum On-Time Considerations...29 High-Side Bootstrap Capacitor...17 Fault Conditions: Current Limit and Foldback.. 29 Dead Time Control (DTCA and DTCB Pins).. 17 Fault Conditions: Overvoltage Protection...29 Startup and Shutdown (RUNx and Fault Conditions: Overtemperature TRACK/SSx Pins).. 17 Protection... 29 Light Load Operation: Burst Mode Phase-Locked Loop and Frequency Operation, Pulse Skipping Mode, or Synchronization..29 Forced Continuous Mode (MODE Pin)...18 Efficiency Considerations... 30 Frequency Selection, Spread Spectrum, Checking Transient Response... 30 and Phase-Locked Loop (FREQ and Design Example... 31 PLLIN/SPREAD Pins).. 18 PCB Layout Checklist...32 Output Overvoltage Protection... 19 PCB Layout Debugging..34 Foldback Current..19 Typical Applications..35 Power-Good... 19 Related Products..39 Applications Information.. 20 Outline Dimensions... 40 Inductor Value Calculation..20 Ordering Guide...40 Inductor Core Selection..20 Evaluation Boards.. 41
REVISION HISTORY 4/2023—Revision 0: Initial Version analog.com Rev. 0 | 2 of 41
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
LTC7890 TABLE OF CONTENTS
Features.. 1 Current Sense Selection.. 20 Applications... 1 Low Value Resistor Current Sensing..21 Typical Application Circuit ...1 Inductor DCR Current Sensing...21 General Description...1 Setting the Operating Frequency... 22 Specifications.. 3 Selecting the Light Load Operating Mode..22 Electrical Characteristics.. 3 Dead Time Control (DTCA and DTCB Pins).. 23 Absolute Maximum Ratings...6 Power FET Selection..24 ESD Caution...6 CIN and COUT Selection..25 Pin Configuration and Function Descriptions.. 7 Setting the Output Voltage... 26 Typical Performance Characteristics... 10 RUNx Pins and Undervoltage Lockout...26 Theory of Operation...16 Soft Start and Tracking (TRACK/SSx Pin)... 26 Functional Diagram.. 16 2-Phase Single Output Operation.. 27 Main Control Loop..16 INTVCC Regulators (OPTI-DRIVE)...27 Power and Bias Supplies (VIN, EXTVCC, Topside FET Driver Supply (CB)...29 DRVCC, and INTVCC)..16 Minimum On-Time Considerations...29 High-Side Bootstrap Capacitor...17 Fault Conditions: Current Limit and Foldback.. 29 Dead Time Control (DTCA and DTCB Pins).. 17 Fault Conditions: Overvoltage Protection...29 Startup and Shutdown (RUNx and Fault Conditions: Overtemperature TRACK/SSx Pins).. 17 Protection... 29 Light Load Operation: Burst Mode Phase-Locked Loop and Frequency Operation, Pulse Skipping Mode, or Synchronization..29 Forced Continuous Mode (MODE Pin)...18 Efficiency Considerations... 30 Frequency Selection, Spread Spectrum, Checking Transient Response... 30 and Phase-Locked Loop (FREQ and Design Example... 31 PLLIN/SPREAD Pins).. 18 PCB Layout Checklist...32 Output Overvoltage Protection... 19 PCB Layout Debugging..34 Foldback Current..19 Typical Applications..35 Power-Good... 19 Related Products..39 Applications Information.. 20 Outline Dimensions... 40 Inductor Value Calculation..20 Ordering Guide...40 Inductor Core Selection..20 Evaluation Boards.. 41
REVISION HISTORY 4/2023—Revision 0: Initial Version analog.com Rev. 0 | 2 of 41
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