Datasheet LT8494 (Analog Devices) - 3

LT8494
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating junction temperature range, otherwise specifications are at TA = 25°C. VIN = VSWEN = 12V, VBIAS = 5V, unless otherwise noted (Note 2). PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum VIN Operating Voltages VBIAS < 2.5V l 2.4 2.5 V VBIAS ≥ 2.5V l 0 V Minimum BIAS Operating Voltages VIN < 2.5V l 2.4 2.5 V VIN ≥ 2.5V l 0 V Power Switch Driver (PSD) Overvoltage Threshold VIN or BIAS Rising l 32.1 34 36.5 V (Note 4) VIN or BIAS Falling l 32 33.9 36.4 V Power Switch Driver (PSD) Overvoltage Threshold 100 mV Hysteresis (Note 4) Quiescent Current from VIN VSWEN = 0V 0.3 0.9 µA VSWEN = 5V, VFB = 1.25V 3.0 4.8 µA VSWEN = 5V, VFB = 1.25V (LT8494E, LT8494I) l 3.0 6.2 µA VSWEN = 5V, VFB = 1.25V (LT8494H) l 3.0 8.0 µA Quiescent Current from BIAS VSWEN = 0V 0.07 0.5 µA VSWEN = 5V, VFB = 1.25V 1.7 2.8 µA VSWEN = 5V, VFB = 1.25V (LT8494E, LT8494I) l 1.7 3.5 µA VSWEN = 5V, VFB = 1.25V (LT8494H) l 1.7 10 µA BIAS to VIN Comparator Threshold VBIAS-VIN, VBIAS Rising, VIN = 12V l 0.55 0.9 1.2 V VBIAS-VIN, VBIAS Falling, VIN = 12V l 0.17 0.37 0.57 V Hysteresis (Rising-Falling Threshold) l 0.20 0.53 0.8 V Feedback Voltage l 1.178 1.202 1.230 V FB Pin Bias Current (Note 7) VFB = 1.202V 0.1 20 nA FB Voltage Line Regulation 5V ≤ VIN ≤ 32V, BIAS = 5V 0.2 10 m%/V 5V ≤ VIN ≤ 32V, BIAS = 0V 0.2 10 m%/V Minimum Switch Off-Time 70 ns Minimum Switch On-Time 95 ns Switching Frequency RT = 68.1k l 0.92 1.0 1.06 MHz RT = 324k l 219 250 280 kHz Switch Current Limit at Minimum Duty Cycle (Note 5) l 2.1 2.55 2.95 A Switch Current Limit at Maximum Duty Cycle (Note 6) l 1.3 1.85 2.4 A Switch VCESAT ISW = 1.2A 340 mV Switch Leakage Current (Note 7) VSW = 12V, VSWEN = 0V 0.01 1 μA Soft-Start Charging Current (Note 7) VSS = 100mV l 5.2 8.2 12.2 μA SWEN Pin Current (Note 7) VSWEN = 1.2V 0 25 nA VSWEN = 5V 35 200 nA VSWEN = 12V 240 550 nA SWEN Rising Voltage Threshold l 0.9 1 1.1 V SWEN Voltage Hysteresis 30 mV PG Threshold as % of VFB Regulation Voltage VFB Rising l 86 92 97 % VFB Falling l 82 88 93 % PG Hysteresis 46 mV PG Output Voltage Low ISINK = 1.25mA l 33 150 mV ISINK = 100μA, VBIAS = 0V, VIN = 1.3V l 15 150 mV ISINK = 100μA, VBIAS = 1.3V, VIN = 0V l 15 150 mV PG Leakage Current VPG = 5V (LT8494E, LT8494I) l 0 0.3 μA VPG = 5V (LT8494H) l 0 1.0 μA 8494fa For more information www.linear.com/LT8494 3 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Related Parts