Datasheet LTC3783 (Analog Devices) - 3

LTC3783
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C. VIN = 12V, VRUN = 1.5V, VSYNC = 0V, VFBP = VREF, RT = 20k, unless otherwise specified. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Main Control Loop/Whole System
VIN Input Voltage Range 3 36 V IQ Input Voltage Supply Current (Note 4) Continuous Mode VOV/FB = 1.5V, VITH = 0.75V 1.5 mA Shutdown Mode VRUN = 0V 20 µA V + RUN Rising RUN Input Threshold Voltage 1.348 V V – RUN Falling RUN Input Threshold Voltage 1.223 1.248 1.273 V VRUN(HYST) RUN Pin Input Threshold Hysteresis 100 mV IRUN RUN Pin Input Current 5 nA VSENSE(MAX) Maximum Current Sense Threshold 125 150 180 mV ISENSE(ON) SENSE Pin Current (GATE High) VSENSE = 0V 70 µA ISENSE(OFF) SENSE Pin Current (GATE Low) VSENSE = 36V 0.2 µA ISS Soft-Start Pin Output Current VSS = 0V -50 µA
Voltage/Temperature Reference
VREF Reference Voltage 1.218 1.230 1.242 V l 1.212 1.248 V IREF Max Reference Pin Output Current 0.5 mA ∆VREF/∆VIN Reference Voltage Line Regulation 3V ≤ VIN ≤ 36V 0.002 0.02 %/V ∆VREF/∆IREF Reference Voltage Load Regulation 0mA ≤ IREF ≤ 0.5mA 0.2 1.0 %/mA TMAX Overtemperature SD Threshold Rising 165 °C THYST Overtemperature Hysteresis 25 °C
Error Amplifier
IOV/FB OV/FB Pin Input Current 18 60 nA ∆VOV/FB(OV) OV/FB Overvoltage Lockout Threshold VOV/FB(OV) – VOV/FB(NOM) in %, VFBP ≤ VREF 7 % VOV/FB(FB) OV/FB Pin Regulation Voltage 2.5V < VFBP < 36V 1.212 1.230 1.248 V IFBP , IFBN Error Amplifier Input Current 0V ≤ VFBP ≤ VREF –0.4 µA 2.5V < VFBP < 36V 50 µA VFBP – VFBN Error Amplifier Offset Voltage 0V ≤ VFBP ≤ VREF –3 3 mV (Note 5) 2.5V < VFBP ≤ 36V (VILIM = VREF) 100 mV 2.5V < VFBP ≤ 36V (VILIM = 0.123V) 10 mV gm Error Amplifier Transconductance VFBP ≤ VREF 1.7 mmho 2.5V < VFBP < 36V 14 mmho AVOL Error Amplifier Open-Loop Gain 500 V/V
Oscillator
fOSC Oscillator Frequency RFREQ = 20kΩ 250 300 350 kHz Oscillator Frequency Range 20 1000 kHz DMAX Maximum Duty Cycle 85 90 97 % fSYNC/fOSC Recommended Max SYNC Freq Ratio fOSC = 300kHz (Note 6) 1.25 1.3 tSYNC(MIN) SYNC Minimum Input Pulse Width VSYNC = 0V to 5V 25 ns tSYNC(MAX) SYNC Maximum Input Pulse Width VSYNC = 0V to 5V 0.8/fOSC ns VIH(SYNC) SYNC Input Voltage High Level 1.2 V VHYST(SYNC) SYNC Input Voltage Hysteresis 0.5 V 3783fb 3 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Pin Functions Block Diagram Operation Package Description Related Parts