Datasheet LT3570 (Analog Devices) - 3

LT3570
ELECTRICAL CHARACTERISTICS The
l
denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN1,2,3 = 12V, VSHDN1,2,3 = 12V unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum Operating Voltage (VIN1) (Note 3) l 2.1 2.5 V Minimum Operating Voltage (VIN2) (Note 3) l 2.1 2.5 V Shutdown Current (Note 4) VSHDN1,2,3 = 0V 0 1.5 μA VIN1 Quiescent Current VSHDN1 = 12V, VSHDN2,3 = 0V, VC1 = 0.4V (Not Switching) 3.2 4.5 mA VSHDN1 = 0V, VSHDN2,3 = 12V 65 150 μA VIN2 Quiescent Current VSHDN1,3 = 0V, VSHDN2 = 12V, VC2 = 0.4V (Not Switching) 3.5 4.5 mA VSHDN1,3 = 12V, VSHDN2 = 0V 3.5 4.5 mA VIN3 Quiescent Current VSHDN1,2 = 0V, VSHDN3 = 12V 700 950 μA VSHDN1,2 = 12V, VSHDN3 = 0V 0 1.5 μA Bias Quiescent Current VBIAS = 2.5V 2.3 3.1 mA VSHDN1,2,3 Pin Threshold IVIN2 > 100μA 0.3 1.4 V VSHDN1,2,3 Pin UVLO l 1.1 1.25 1.4 V VSHDNX Pin Current VSHDNX = 12V, VSHDNY,Z = 0V (Note 5) 30 50 μA VSHDN1,2,3 = 0V 0.1 1.5 μA Switching Frequency RT = 44.2k 450 500 550 kHz RT = 7.87k 1900 2100 2300 kHz Maximum Duty Cycle RT = 44.2k 95 % RT = 7.87k 80 % Synchronous Frequency Threshold 0.3 1.5 V Synchronous Frequency Range 650 2750 kHz Synchronous Frequency Minimum On/Off 50 ns Time FB1,2,3 Pin Voltage l 772 788 804 mV FB1,2,3 Pin Voltage Line Regulation VVIN1,2,3 = 2.5V to 36V, VC1,2 = 1V 0.01 %/V FB1,2 Pin Bias Current VFB1,2 = 800mV, VC1,2 = 1V (Note 6) 30 200 nA FB3 Pin Bias Current VFB3 = 800mV (Note 6) 30 200 nA SS1,2 Pin Source Current VSS1,2 = 500mV 4.5 μA VC1,2 Pin Source Current VFB1,2 = 600mV 12 μA VC1,2 Pin Sink Current VFB1,2 = 1V 12 μA
SW1
Error Amplifi er 1 Transconductance 190 μMho Error Amplifi er 1 Voltage Gain 100 V/V VC1 Pin Switching Threshold 750 mV VC1 to SW1 Current Gain 5.9 A/V SW1 Current Limit (Note 7) 1.5 2.4 3.1 A SW1 VCESAT ISW1 = 1A (Note 7) 240 mV SW1 Leakage Current SW1 = 40V, VSHDN1 = 0V 0.2 5 μA 3570fb 3