Datasheet LT3952A (Analog Devices) - 4
| Manufacturer | Analog Devices |
| Description | 60V LED Driver with 4A Switch Current |
| Pages / Page | 30 / 4 — ELECTRICAL CHARACTERISTICS. The |
| Revision | A |
| File Format / Size | PDF / 2.3 Mb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS. The
Model Line for this Datasheet
Text Version of Document
LT3952A
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = IVINP = IVINN = 12V, ISP = ISN = 24V, EN/UVLO = PWM = 3V, CTRL = 2V, OVLO = 0V unless otherwise noted PARAMETER CONDITIONS MIN TYP MAX UNITS TG Gate Driver
PWM Input High Threshold PWM Rising l 1.15 1.2 1.25 V PWM Hysteresis 20 mV TG On Voltage VISP-TG, VISP > 10V 8.5 9.5 V TG Off Voltage VISP-TG, PWM = 0V 0 0.3 V TG Turn-On Time CLOAD = 470pF, PWM Rising 165 ns TG Turn-Off Time CLOAD = 470pF, PWM Falling 135 ns
Output Voltage Feedback
FB Voltage Regulation Threshold (VFB) CTRL = 1.5V 1.188 1.200 1.212 V l 1.182 1.200 1.218 V FB Open-LED Threshold FB Rising VFB – VFB – VFB – V 65mV 45mV 25mV FB Open-LED Threshold Hysteresis 15 mV FB Overvoltage Threshold FB Rising VFB + VFB + VFB + V 10mV 30mV 40mV FB Overvoltage Threshold Hysteresis 15 mV FB Pin Bias Current l 20 100 nA Feedback Line Regulation 3V < VIN < 42V 0.0003 %/V FB to VC Transconductance 450 µS VC Output Impedance 5000 kΩ
Soft-Start
Soft-Start Sourcing Current Current Out of Pin, SS = 0.1V 18 25 37 µA Soft-Start Sinking Current SS = 1.8V 1.5 2.5 4.1 µA Soft-Start Hiccup Retry Threshold 200 mV Soft-Start Strong Pull-Down On-Resistance 120 Ω
Oscillator
RT Voltage 1.20 V Switching Frequency RT = 470k 180 215 250 kHz RT = 90.9k 0.93 1.0 1.04 MHz RT = 40.2k l 1.90 2.0 2.10 MHz RT = 25.5k 2.75 3.0 3.25 MHz Maximum Duty Cycle RT = 470k 98 99 % SYNC = 300kHz Clock Signal, RT = 470k 97 98 % RT = 90.9k 94 95 % RT = 40.2k l 87 90 % RT = 25.5k 80 % Minimum Off-Time 50 ns Minimum On-Time 75 ns SYNC/SPRD Pin Resistance to GND VSYNC = 2V 100 kΩ SYNC/SPRD Input High Threshold 1.5 V SYNC/SPRD Input Low Threshold 0.4 V Spread Spectrum Minimum Step as Percentage of fSW 1 % Spread Spectrum Maximum Step as Percentage of fSW 31 % Rev A 4 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 Package Description Revision History 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. VIN = IVINP = IVINN = 12V, ISP = ISN = 24V, EN/UVLO = PWM = 3V, CTRL = 2V, OVLO = 0V unless otherwise noted PARAMETER CONDITIONS MIN TYP MAX UNITS TG Gate Driver
PWM Input High Threshold PWM Rising l 1.15 1.2 1.25 V PWM Hysteresis 20 mV TG On Voltage VISP-TG, VISP > 10V 8.5 9.5 V TG Off Voltage VISP-TG, PWM = 0V 0 0.3 V TG Turn-On Time CLOAD = 470pF, PWM Rising 165 ns TG Turn-Off Time CLOAD = 470pF, PWM Falling 135 ns
Output Voltage Feedback
FB Voltage Regulation Threshold (VFB) CTRL = 1.5V 1.188 1.200 1.212 V l 1.182 1.200 1.218 V FB Open-LED Threshold FB Rising VFB – VFB – VFB – V 65mV 45mV 25mV FB Open-LED Threshold Hysteresis 15 mV FB Overvoltage Threshold FB Rising VFB + VFB + VFB + V 10mV 30mV 40mV FB Overvoltage Threshold Hysteresis 15 mV FB Pin Bias Current l 20 100 nA Feedback Line Regulation 3V < VIN < 42V 0.0003 %/V FB to VC Transconductance 450 µS VC Output Impedance 5000 kΩ
Soft-Start
Soft-Start Sourcing Current Current Out of Pin, SS = 0.1V 18 25 37 µA Soft-Start Sinking Current SS = 1.8V 1.5 2.5 4.1 µA Soft-Start Hiccup Retry Threshold 200 mV Soft-Start Strong Pull-Down On-Resistance 120 Ω
Oscillator
RT Voltage 1.20 V Switching Frequency RT = 470k 180 215 250 kHz RT = 90.9k 0.93 1.0 1.04 MHz RT = 40.2k l 1.90 2.0 2.10 MHz RT = 25.5k 2.75 3.0 3.25 MHz Maximum Duty Cycle RT = 470k 98 99 % SYNC = 300kHz Clock Signal, RT = 470k 97 98 % RT = 90.9k 94 95 % RT = 40.2k l 87 90 % RT = 25.5k 80 % Minimum Off-Time 50 ns Minimum On-Time 75 ns SYNC/SPRD Pin Resistance to GND VSYNC = 2V 100 kΩ SYNC/SPRD Input High Threshold 1.5 V SYNC/SPRD Input Low Threshold 0.4 V Spread Spectrum Minimum Step as Percentage of fSW 1 % Spread Spectrum Maximum Step as Percentage of fSW 31 % Rev A 4 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 Package Description Revision History Typical Application Related Parts
