Datasheet LT8228 (Analog Devices) - 7
| Manufacturer | Analog Devices |
| Description | Bidirectional Synchronous 100V Buck/Boost Controller with Reverse Supply, Reverse Current and Fault Protection |
| Pages / Page | 68 / 7 — ELECTRICAL CHARACTERISTICS. The. denotes the specifications which apply … |
| File Format / Size | PDF / 3.8 Mb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS. The. denotes the specifications which apply over the full operating
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LT8228
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. DS1 = V1D = 48V, DS2 = BIAS = 14V, RIN1 = 1k, RIN2 = 1k, and ISHARE = INTVCC unless otherwise specified. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
∆ISET2P Buck Mode Output Current (ISET2P) RSNS2 = 5Ω, RSET2P = 24.3k, VCM2 = 14V, l 0 ±2.5 % Regulation Error (Note 15) DRXN = 2V (Buck Mode) ∆ISHAREBUCK Buck Mode Output Current Sharing Error RSNS2 = 5Ω, RSET2P = 24.3K, VCM2 = 14V, l 0 ±4 % (Note 16) DRXN = 2V (Buck Mode), ISHARE = 0.605V
Boost Voltage and Current Regulation
VFB1 FB1 Regulation Voltage (Note 13) l 1.198 1.210 1.222 V IFB1 FB1 Pin Bias Current l 10 50 nA gmFB1 V1 Error Amplifier Transconductance 0.8 ms VISET1N ISET1N Regulation Voltage (Note 14) l 1.198 1.210 1.222 V gmISET1N ISET1N Error Amplifier Transconductance 0.8 ms VISET2N ISET2N Regulation Voltage (Note 14) l 1.198 1.210 1.222 V gmISET2N ISET2N Error Amplifier Transconductance 0.8 ms RVC1 VC1 Output Impedance 1000 kΩ ∆ISET1N Boost Mode Output Current (ISET1N) RSNS1 = 5Ω, RSET1N = 24.3k, VCM1 = 48V, l 0 ±2.5 % Regulation Error (Note 15) DRXN = 2V (Buck Mode) ∆ISET2N Boost Mode Input Current (ISET2N) RSNS2 = 5Ω, RSET2N = 24.3k, VCM2 = 14V, l 0 ±2.5 % Regulation Error (Note 15) DRXN = 2V (Buck Mode) ∆ISHAREBOOST Boost Mode Output Current Sharing Error RSNS1 = 5Ω, RSET1N = 24.3k, VCM1 = 14V, l 0 ±4 % (Note 16) DRXN = 2V (Buck Mode), ISHARE = 0.605V
Switching MOSFET Driver
RTG Pull-Up On-Resistance 2.5 Ω Pull-Down On-Resistance 1.0 Ω RBG Pull-Up On-Resistance 2.5 Ω Pull-Down On-Resistance 1.0 Ω tRTG TG Rise Time CLOAD = 6800pF (10% to 90%) 50 ns tFTG TG Fall Time CLOAD = 6800pF (10% to 90%) 20 ns tRBG BG Rise Time CLOAD = 6800pF (10% to 90%) 50 ns tFBG BG Fall Time CLOAD = 6800pF (10% to 90%) 20 ns tDTGBG TG Off to BG On Delay CLOAD = 6800pF Each Driver (50% to 50%) 50 ns tDBGTG BG Off to TG On Delay CLOAD = 6800pF Each Driver (50% to 50%) 50 ns tONBUCK Min TG On-Time in Buck Mode DRXN = 2V 150 ns tONBOOST Min BG On-Time in Boost Mode DRXN = 0V 150 ns tOFFBOOST Min BG Off-Time in Boost Mode DRXN = 0V 200 ns tDTGBG,V1D = 48V TG Off to BG On Delay, V1D = 48V (Note 17) 60 ns tDTGBG,V1D =100V TG Off to BG On Delay, V1D = 100V (Note 17) 60 ns
PLL and Oscillator
fPROG Programmable Frequency RRT = 124k l 75 80 85 kHz RRT = 100k l 95 100 105 kHz RRT = 14k l 540 600 660 kHz fSYNC Synchronizable Frequency l 82 700 kHz fSPSC,MAX Spread Spectrum Maximum Frequency RRT = 100k, fPROG = 100kHz l 130 145 kHz fSPSC,MIN Spread Spectrum Maximum Frequency RRT = 100k, fPROG = 100kHz l 65 80 kHz Rev. 0 For more information www.analog.com 7 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
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. DS1 = V1D = 48V, DS2 = BIAS = 14V, RIN1 = 1k, RIN2 = 1k, and ISHARE = INTVCC unless otherwise specified. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
∆ISET2P Buck Mode Output Current (ISET2P) RSNS2 = 5Ω, RSET2P = 24.3k, VCM2 = 14V, l 0 ±2.5 % Regulation Error (Note 15) DRXN = 2V (Buck Mode) ∆ISHAREBUCK Buck Mode Output Current Sharing Error RSNS2 = 5Ω, RSET2P = 24.3K, VCM2 = 14V, l 0 ±4 % (Note 16) DRXN = 2V (Buck Mode), ISHARE = 0.605V
Boost Voltage and Current Regulation
VFB1 FB1 Regulation Voltage (Note 13) l 1.198 1.210 1.222 V IFB1 FB1 Pin Bias Current l 10 50 nA gmFB1 V1 Error Amplifier Transconductance 0.8 ms VISET1N ISET1N Regulation Voltage (Note 14) l 1.198 1.210 1.222 V gmISET1N ISET1N Error Amplifier Transconductance 0.8 ms VISET2N ISET2N Regulation Voltage (Note 14) l 1.198 1.210 1.222 V gmISET2N ISET2N Error Amplifier Transconductance 0.8 ms RVC1 VC1 Output Impedance 1000 kΩ ∆ISET1N Boost Mode Output Current (ISET1N) RSNS1 = 5Ω, RSET1N = 24.3k, VCM1 = 48V, l 0 ±2.5 % Regulation Error (Note 15) DRXN = 2V (Buck Mode) ∆ISET2N Boost Mode Input Current (ISET2N) RSNS2 = 5Ω, RSET2N = 24.3k, VCM2 = 14V, l 0 ±2.5 % Regulation Error (Note 15) DRXN = 2V (Buck Mode) ∆ISHAREBOOST Boost Mode Output Current Sharing Error RSNS1 = 5Ω, RSET1N = 24.3k, VCM1 = 14V, l 0 ±4 % (Note 16) DRXN = 2V (Buck Mode), ISHARE = 0.605V
Switching MOSFET Driver
RTG Pull-Up On-Resistance 2.5 Ω Pull-Down On-Resistance 1.0 Ω RBG Pull-Up On-Resistance 2.5 Ω Pull-Down On-Resistance 1.0 Ω tRTG TG Rise Time CLOAD = 6800pF (10% to 90%) 50 ns tFTG TG Fall Time CLOAD = 6800pF (10% to 90%) 20 ns tRBG BG Rise Time CLOAD = 6800pF (10% to 90%) 50 ns tFBG BG Fall Time CLOAD = 6800pF (10% to 90%) 20 ns tDTGBG TG Off to BG On Delay CLOAD = 6800pF Each Driver (50% to 50%) 50 ns tDBGTG BG Off to TG On Delay CLOAD = 6800pF Each Driver (50% to 50%) 50 ns tONBUCK Min TG On-Time in Buck Mode DRXN = 2V 150 ns tONBOOST Min BG On-Time in Boost Mode DRXN = 0V 150 ns tOFFBOOST Min BG Off-Time in Boost Mode DRXN = 0V 200 ns tDTGBG,V1D = 48V TG Off to BG On Delay, V1D = 48V (Note 17) 60 ns tDTGBG,V1D =100V TG Off to BG On Delay, V1D = 100V (Note 17) 60 ns
PLL and Oscillator
fPROG Programmable Frequency RRT = 124k l 75 80 85 kHz RRT = 100k l 95 100 105 kHz RRT = 14k l 540 600 660 kHz fSYNC Synchronizable Frequency l 82 700 kHz fSPSC,MAX Spread Spectrum Maximum Frequency RRT = 100k, fPROG = 100kHz l 130 145 kHz fSPSC,MIN Spread Spectrum Maximum Frequency RRT = 100k, fPROG = 100kHz l 65 80 kHz Rev. 0 For more information www.analog.com 7 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
