Datasheet LT8228 (Analog Devices) - 9
| Manufacturer | Analog Devices |
| Description | Bidirectional Synchronous 100V Buck/Boost Controller with Reverse Supply, Reverse Current and Fault Protection |
| Pages / Page | 68 / 9 — TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. … |
| File Format / Size | PDF / 3.8 Mb |
| Document Language | English |
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. BUCK EFFICIENCY AND OPERATION
Model Line for this Datasheet
Text Version of Document
LT8228
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. BUCK EFFICIENCY AND OPERATION Efficiency vs V2 Current (Buck) Efficiency vs V1 (Buck) (V1 = 48V, V2 = 14V) (V2 = 14V, IV2 = 20A) Load Step (Buck)
100 40 100 90 LOAD EFFICIENCY 10A/DIV 80 98 30 70 POWER LOSS (W) V2 (AC) 60 96 500mV/DIV 50 20 I 40 94 L EFFICIENCY (%) EFFICIENCY (%) 10A/DIV 30 10 20 92 200µs/DIV 8228 G03 10 POWER LOSS 0 0 90 0.1 1 10 100 24 28 32 36 40 44 48 52 56 LOAD CURRENT (A) INPUT VOLTAGE (V) 8228 G01 8228 G02
Inductor Current at Light Load Start-Up at Prebiased Load (Buck) Soft Start-Up (Buck) (Buck)
V2 5V/DIV IL V2 500mA/DIV 5V/DIV SS IL 100mV/DIV 5A/DIV 4µs/DIV 8228 G04 400µs/DIV 8228 G05 400µs/DIV 8228 G06
Output Higher Than Input, V2 > V1 Short-Circuit/Voltage and Current ISET2P and IMON2 (Reverse Current Protection, Buck) Regulation Transition (Buck) Measurement Accuracy
DG1 12 ISET2P 10V/DIV V2 IMON2 5V/DIV 10 V1 10V/DIV 8 IL V2 20A/DIV 6 10V/DIV I 4 L ERROR (%) 20A/DIV ISET2P 1V/DIV 2 2ms/DIV 8228 G07 400µs/DIV 8228 G08 0 –2 0 10 20 30 40 50 60 70 80 90 100 VRSNS2 (mV) 8228 G09 Rev. 0 For more information www.analog.com 9 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Buck Efficiency and Operation Typical Performance Characteristics Boost Efficiency and Operation ENABLE, Supply Current and VCC SS Current, Frequency, Thresholds and Driver Protection MOSFET Controller Pin Functions Block Diagram Operation Overview Buck Mode Operation Boost Mode Operation V1 Protection MOSFET Controller Operation V2 Protection MOSFET Controller Operation Mode of Operation (DRXN) Enable and Soft-Start (Enable and SS) Paralleling Multiple Controllers (ISHARE AND IGND) BIAS Supply and VCC Regulators Strong Gate Drivers Frequency Selection, Spread Spectrum and Phase-Locked Loop (RT and SYNC) FAULT Monitoring and REPORT Feature Applications Information Introduction Programming the Switching Frequency Inductor Selection RSNS2 and RIN2 Selection for Peak Inductor Current RSET2P Selection for V2 Output Current Limit (Buck Mode) RSET2N Selection for V2 Input Current Limit (Boost Mode) RMON2 Selection for V2 Current Monitoring RSNS1 and RIN1 Selection RSET1P Selection for V1 Input Current Limit (Buck Mode) RSET1N Selection for V1 Output Current Limit (Boost Mode) RMON1 Selection for V1 Current Monitoring Output Voltage, Input Undervoltage and Output Overvoltage Programming Power MOSFET Selection and Efficiency Considerations Optional Schottky Diode (D2 and D3) Selection Top MOSFET Driver Supply (CBST, DBST) Power Path Capacitor Selection Loop Compensation Inrush Current Control Boost Output Short Protection and Timer FAULT Conditions Soft-Start REPORT Feature Paralleling Multiple LT8228s BIAS, DRVCC, INTVCC and Power Dissipation Thermal Shutdown Pin Clearance/Creepage Consideration Efficiency Considerations PC Board Layout Checklist Design Example Package Description Typical Application Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Typical Application Related Parts
TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. BUCK EFFICIENCY AND OPERATION Efficiency vs V2 Current (Buck) Efficiency vs V1 (Buck) (V1 = 48V, V2 = 14V) (V2 = 14V, IV2 = 20A) Load Step (Buck)
100 40 100 90 LOAD EFFICIENCY 10A/DIV 80 98 30 70 POWER LOSS (W) V2 (AC) 60 96 500mV/DIV 50 20 I 40 94 L EFFICIENCY (%) EFFICIENCY (%) 10A/DIV 30 10 20 92 200µs/DIV 8228 G03 10 POWER LOSS 0 0 90 0.1 1 10 100 24 28 32 36 40 44 48 52 56 LOAD CURRENT (A) INPUT VOLTAGE (V) 8228 G01 8228 G02
Inductor Current at Light Load Start-Up at Prebiased Load (Buck) Soft Start-Up (Buck) (Buck)
V2 5V/DIV IL V2 500mA/DIV 5V/DIV SS IL 100mV/DIV 5A/DIV 4µs/DIV 8228 G04 400µs/DIV 8228 G05 400µs/DIV 8228 G06
Output Higher Than Input, V2 > V1 Short-Circuit/Voltage and Current ISET2P and IMON2 (Reverse Current Protection, Buck) Regulation Transition (Buck) Measurement Accuracy
DG1 12 ISET2P 10V/DIV V2 IMON2 5V/DIV 10 V1 10V/DIV 8 IL V2 20A/DIV 6 10V/DIV I 4 L ERROR (%) 20A/DIV ISET2P 1V/DIV 2 2ms/DIV 8228 G07 400µs/DIV 8228 G08 0 –2 0 10 20 30 40 50 60 70 80 90 100 VRSNS2 (mV) 8228 G09 Rev. 0 For more information www.analog.com 9 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Buck Efficiency and Operation Typical Performance Characteristics Boost Efficiency and Operation ENABLE, Supply Current and VCC SS Current, Frequency, Thresholds and Driver Protection MOSFET Controller Pin Functions Block Diagram Operation Overview Buck Mode Operation Boost Mode Operation V1 Protection MOSFET Controller Operation V2 Protection MOSFET Controller Operation Mode of Operation (DRXN) Enable and Soft-Start (Enable and SS) Paralleling Multiple Controllers (ISHARE AND IGND) BIAS Supply and VCC Regulators Strong Gate Drivers Frequency Selection, Spread Spectrum and Phase-Locked Loop (RT and SYNC) FAULT Monitoring and REPORT Feature Applications Information Introduction Programming the Switching Frequency Inductor Selection RSNS2 and RIN2 Selection for Peak Inductor Current RSET2P Selection for V2 Output Current Limit (Buck Mode) RSET2N Selection for V2 Input Current Limit (Boost Mode) RMON2 Selection for V2 Current Monitoring RSNS1 and RIN1 Selection RSET1P Selection for V1 Input Current Limit (Buck Mode) RSET1N Selection for V1 Output Current Limit (Boost Mode) RMON1 Selection for V1 Current Monitoring Output Voltage, Input Undervoltage and Output Overvoltage Programming Power MOSFET Selection and Efficiency Considerations Optional Schottky Diode (D2 and D3) Selection Top MOSFET Driver Supply (CBST, DBST) Power Path Capacitor Selection Loop Compensation Inrush Current Control Boost Output Short Protection and Timer FAULT Conditions Soft-Start REPORT Feature Paralleling Multiple LT8228s BIAS, DRVCC, INTVCC and Power Dissipation Thermal Shutdown Pin Clearance/Creepage Consideration Efficiency Considerations PC Board Layout Checklist Design Example Package Description Typical Application Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Typical Application Related Parts
