Datasheet LT8708-1 (Analog Devices) - 6

LT8708-1
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C. VINCHIP =12V, SHDN = 3V, DIR = 3.3V unless otherwise noted. (Note 3). PARAMETER CONDITIONS MIN TYP MAX UNITS Current Regulation Loops (Refer to Block Diagram to Locate Amplifiers)
Regulation Voltages for IMON_INP and IMON_OP VC = 1.2V l 1.185 1.209 1.231 V Regulation Voltages for IMON_INN VC = 1.2V l 1.185 1.21 1.24 V Line Regulation for IMON_INP, IMON_INN and IMON_OP Error VINCHIP = 12V to 80V 0.002 0.005 %/V Amp Reference Voltage CSPIN Bias Current VCSPIN = 12V 0.01 µA VCSPIN = 1.5V 0.01 µA CSNIN Bias Current BOOST Capacitor Charge Control Block Not Active VSWEN = 3.3V, VCSPIN = VCSNIN = 12V 84 µA VSWEN = 3.3V, VCSPIN = VCSNIN = 1.5V 4.25 µA VSWEN = 0V 0.01 µA CSPIN, CSNIN Common Mode Operating Voltage Range l 0 80 V CSPIN, CSNIN Differential Mode Operating Voltage Range l –100 100 mV IMON_INP Output Current VCSPIN – VCSNIN = 50mV, VCSNIN = 5V 67 70 73 µA VCSPIN – VCSNIN = 50mV, VCSNIN = 5V l 64.5 70 75.5 µA VCSPIN – VCSNIN = 5mV, VCSNIN = 5V 22.5 25 27.5 µA VCSPIN – VCSNIN = 5mV, VCSNIN = 5V l 20 25 30 µA IMON_INN Output Current VCSNIN – VCSPIN = 50mV, VCSNIN = 5V 66 70 74 µA VCSNIN – VCSPIN = 50mV, VCSNIN = 5V l 65 70 75 µA VCSNIN – VCSPIN = 5mV, VCSNIN = 5V 19 25 30.5 µA VCSNIN – VCSPIN = 5mV, VCSNIN = 5V l 18 25 32 µA IMON_INP and IMON_INN Max Output Current l 120 µA IMON_INP Error Amp EA5 gm 190 µmho IMON_INP Error Amp EA5 Voltage Gain 130 V/V IMON_INN Error Amp EA1 gm FBIN = 0V, FBOUT = 3.3V 190 µmho IMON_INN Error Amp EA1 Voltage Gain FBIN = 0V, FBOUT = 3.3V 130 V/V CSPOUT Bias Current VCSPOUT = 12V 0.01 µA VCSPOUT = 1.5V 0.01 µA CSNOUT Bias Current BOOST Capacitor Charge Control Block Not Active VSWEN = 3.3V, VCSPOUT = VCSNOUT = 12V 83 µA VSWEN = 3.3V, VCSPOUT = VCSNOUT = 1.5V 4.25 µA VSWEN = 0V 0.01 µA CSPOUT, CSNOUT Common Mode Operating Voltage Range l 0 80 V CSPOUT, CSNOUT Differential Mode Operating Voltage Range l –100 100 mV IMON_ON Output Current VCSNOUT – VCSPOUT = 50mV, VCSNOUT = 5V 67 70 73 µA VCSNOUT – VCSPOUT = 50mV, VCSNOUT = 5V l 65 70 75 µA VCSNOUT – VCSPOUT = 5mV, VCSNOUT = 5V 22.5 25 27.5 µA VCSNOUT – VCSPOUT = 5mV, VCSNOUT = 5V l 20.5 25 29 µA VCSNOUT – VCSPOUT = −5mV, VCSNOUT = 5V 12.5 15 17.5 µA VCSNOUT – VCSPOUT = −5mV, VCSNOUT = 5V l 10.5 15 19.5 µA IMON_ON Max Output Current l 120 µA CSPOUT–CSNOUT Regulation Voltage Regulate VC to 1.2V ICP = 1.218V, ICN = 0V l 43 50 55 mV RIMON_OP = 17.4kΩ V ICP = 0V, ICN = 1.218V l –55 –50 –44 mV CSNOUT = 12V ICP = ICN = 0.348V l –6 0 6 mV Rev 0 6 For more information www.analog.com Document Outline 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 Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Common LT8708-1 and LT8708 Features Adding Phases to an LT8708 Application Adding Phases: The Master LT8708 Adding Phases: The Slave LT8708-1 Start-Up Start-Up: SWEN Pin Start-Up: Soft-Start of Switching Regulator Control Overview Power Switch Control Unidirectional and Bidirectional Conduction Error Amplifiers Transfer Function: IOUT(SLAVE) Vs IOUT(MASTER) Transfer Function: CCM Transfer Function: DCM, HCM and Burst Mode Operation Current Monitoring and Limiting Monitoring: IOUT(SLAVE) Monitoring and Limiting: IIN(SLAVE) Multiphase Clocking Applications Information Quick-Start Multiphase Setup Quick Setup: Design the Master Phase Quick Setup: Design the Slave Phase(s) Quick Setup: Evaluation Choosing the Total Number of Phases Operating Frequency Selection CIN and COUT Selection CIN and COUT Selection: VIN Capacitance CIN and COUT Selection: VOUT Capacitance VINHIMON, VOUTLOMON and RVSOFF Configuring the IIN(SLAVE) Current Limits Regulating IOUT(SLAVE) IOUT(SLAVE): Circuit Description IOUT(SLAVE): Configuration Loop Compensation Voltage Lockouts Circuit Board Layout Checklist Design Example Typical Applications Package Description Typical Application Related Parts