Datasheet LT8709 (Analog Devices) - 4

LT8709
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications for each channel are at TA = 25°C. VGND – V–VIN = 12V, VEN/FBIN – V–VIN = 12V, VBIAS – V–VIN = 12V, unless otherwise noted. Pin voltages have the following relations: FBY is relative to the GND pin, TG and INTVEE to the BIAS pin, and all other pins to the –VIN pin, unless otherwise stated. Pin currents have the following relations: positive current is denoted as current flowing into the pin; negative current is denoted as current flowing out of the pin, unless otherwise stated. (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS Control Loops (Refer to Block Diagram to Locate Amplifiers)
Current Limit Voltage, VCSP – VCSN IFBY = –67.9µA, Minimum Duty Cycle l 46 50 54 mV IFBY = –67.9µA, Maximum Duty Cycle l 23 31 38 mV IFBY = –108µA, MODE = 0V, Minimum Duty Cycle l –41 –32 –23 mV IFBY = –108µA, MODE = 0V, Maximum Duty Cycle l –65 –51 –38 mV FBY Voltage for Negative Output Voltage Q1 Conducting Current, Current Flowing Out of FBY Pin l –1.28 –1.234 –1.18 V Regulation FBY Voltage for Positive Output Voltage M1 Conducting Current, Current Flowing into FBY Pin l –60 –15.8 25 mV Regulation Negative FBY Pin Bias Current Current Flowing Out of FBY Pin l 81.4 83.5 85.7 µA Positive FBY Pin Bias Current Current Flowing Into FBY Pin l 80.1 83.9 87.5 µA FBY Voltage-to-Current Amp Current Flowing Out of FBY Pin, ΔIFBY = 10µA 1.8 mS Transconductance, ΔIFBY/ΔVFBY Current Flowing into FBY Pin, ΔIFBY = 10µA 1.05 mS FBY Error Amp Transresistance Current Flowing Out of FBY Pin, ΔVVC = 200mV 508 kΩ ΔVVC/ΔIFBY Current Flowing into FBY Pin, ΔVVC = 200mV 516 kΩ FBY Error Amp Current Gain ΔIVC = 2µA 1.5 A/A ΔIVC/ΔIFBY FBY Line Regulation 4.5V ≤ VGND – V–VIN ≤ 80V, VBIAS – V–VIN = 0V –0.02 0.003 0.02 %/V Output Current Sense Regulation VISN = 80V, IFBY = –53µA l 43 50 57 mV Voltage, VISP – VISN VISN = 12V, IFBY = –53µA l 43 50 57 mV VISN = 0V, IFBY = –53µA l 40 50 60 mV VISN = 12V, IFBY = –53µA, INTVEE in UVLO and SS > 1.8V l 17 25 34 mV IMON Regulation Voltage, EA2 IFBY = –53µA l 1.184 1.213 1.24 V IFBY = –53µA, INTVEE in UVLO and SS > 1.8V l 0.885 0.916 0.947 V Output Current Sense Amp ΔIIMON = 10μA 1000 µS Transconductance, A7 Output Current Sense Amp Voltage 11.9 V/V Gain, A7 Output Current Sense Amp Input Negative Input Range –51.8 mV Dynamic Range, A7 Positive Input Range 500 mV IMON Amp Transconductance, EA2 ΔIVC = 2μA, IFBY = –53µA 165 µS IMON Amp Voltage Gain, EA2 VISN = 12V, IFBY = –53µA 65 V/V EN/FBIN Input Regulation Voltage, EA3 IFBY = –53µA l 1.55 1.607 1.662 V EN/FBIN Amp Transconductance, EA3 ΔIVC = 2µA, IFBY = –53µA 140 µS EN/FBIN Amp Voltage Gain, EA3 IFBY = –53µA 55 V/V MODE Forced CCM Threshold To Exit Forced CCM Mode, MODE Rising l 1.19 1.224 1.258 V To Enter Forced CCM Mode, MODE Falling l 1.125 1.175 1.23 V MODE Forced CCM Threshold 49 mV Hysteresis DCM Comparator Threshold in VISN = 80V, To Enter DCM Mode, VISP – VISN Falling l –4.5 2.8 10 mV Pulse-Skipping Mode, MODE = 2V VISN = 12V, To Enter DCM Mode, VISP – VISN Falling l –4.5 2.8 10 mV VISN = 0V, To Enter DCM Mode, VISP – VISN Falling l –7.5 2.8 13 mV DCM Comparator Threshold in VISN = 80V, To Enter DCM Mode, VISP – VISN Falling l –380 –300 –220 mV Forced CCM, MODE = 0V VISN = 12V, To Enter DCM Mode, VISP – VISN Falling l –380 –300 –220 mV VISN = 0V, To Enter DCM Mode, VISP – VISN Falling l –380 –300 –220 mV 8709fa 4 For more information www.linear.com/LT8709