link to page 2 LT3952A ELECTRICAL CHARACTERISTICSThe 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 PARAMETERCONDITIONSMINTYPMAXUNITSPWM Generator PWM Pin Pull-Up/Pull-Down Current PWM = 1.2V, DIM = 0.7V l 5 10 15 µA PWM Generator Lower Threshold Offset 0.2V < DIM < 1.2V VDIM – 15 VDIM + 0 VDIM + 15 mV PWM Generator Upper Threshold Offset 0.2V < DIM < 1.2V VDIM + VDIM + VDIM + mV 800 950 1100 PWM Generator Frequency DIM = 0.7V, CPWM = 22nF 230 Hz DIM Pin Output Current DIM = 0.7V l 13 20 27 µA TG Duty Cycle Using PWM Generator DIM = 0.345V 1 10 25 % DIM = 0.535V 20 30 40 % DIM = 0.725V 40 50 60 % DIM = 1.105V 86 90 94 % Power Switch Switch On-Resistance ISW = 500mA 80 mΩ Switch Leakage Current SW = 60V, CTRL = 0V 2 µA VC to Current Threshold Transconductance 7.5 S Maximum Power Switch Current Limit VC = 2V 4 4.5 5 A Logic Inputs/Outputs EN/UVLO Disable Threshold EN/UVLO Falling l 1.191 1.230 1.269 V EN/UVLO Threshold Internal Hysteresis 75 mV EN/UVLO Hysteresis Current EN/UVLO = 1.25V, Device in Shutdown 2 µA EN/UVLO = 1.5V, Device in Operation 0 0.4 µA OVLO Threshold OVLO Rising l 1.191 1.230 1.269 V OVLO Threshold Hysteresis 25 mV OVLO Input Bias Current OVLO = 1V 15 100 nA SHORTLED On-Resistance ISHORTLED = 1mA 60 Ω SHORTLED Output Low Voltage ISHORTLED = 2mA 0.3 V SHORTLED Off-State Leakage SHORTLED = 42V 1 µA OPENLED On-Resistance IOPENLED = 1mA 60 Ω OPENLED Output Low Voltage IOPENLED = 2mA 0.3 V OPENLED Off-State Leakage OPENLED = 42V 1 µA Note 1: Stresses beyond those listed under Absolute Maximum Ratings Note 3: The LT3952A includes overtemperature protection that is intended may cause permanent damage to the device. Exposure to any Absolute to protect the device during momentary overload conditions. Junction Maximum Rating condition for extended periods may affect device temperature will exceed the maximum operating junction temperature reliability and lifetime. when overtemperature is active. Continuous operating above the specified Note 2: The LT3952AE is guaranteed to meet specified performance from maximum operating junction temperature may impair device reliability. 0°C to 125°C. Specifications over the –40°C to 125°C operating junction Note 4: INTVCC is an output and is not meant to be externally driven. temperature range are assured by design, characterization and correlation with statistical process controls. The LT3952AI is guaranteed to meet performance specifications over the –40°C to 125°C operating junction temperature range. The LT3952AH is guaranteed to meet performance specifications over the full –40°C to 150°C operating junction temperature range. High junction temperatures degrade operating lifetimes. Operating lifetime is derated at junction temperatures greater than 125°C. Rev A For more information www.analog.com 5 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