Datasheet LTC3520 (Analog Devices) - 3

LTC3520
ELECTRICAL CHARACTERISTICS The
l
denotes the specifi cations which apply over the full operating junction temperature range, otherwise specifi cations are at TA = 25°C, SVIN = PVIN1 = PVIN2 = PVIN3 = 3.6V, VOUT1 = 3.3V, RT = 54.9k, unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS
Feedback Voltage (FB2 Pin) (Note 4) l 0.771 0.790 0.809 V Feedback Input Current (FB2 Pin) 1 50 nA PMOS Current Limit (Note 3) l 0.8 1.25 A Maximum Duty Cycle VFB2 = 0.72V l 100 % Minimum Duty Cycle VFB2 = 0.88V l 0 % Soft-Start Charging Current 6 μA SD2 Input High Voltage 1.4 V SD2 Input Low Voltage 0.4 V SD2 Input Current 0.01 1 μA
Buck-Boost Converter
Output Voltage l 2.2 5.25 V PMOS Switch Resistance 0.20 Ω NMOS Switch Resistance 0.15 Ω NMOS Switch Leakage VSW1A = VSW1B = 5V, SVIN = PVIN1 = PVIN2 = PVIN3 = 5V 0.1 5 μA PMOS Switch Leakage VSW1A = VSW1B = 0V, SVIN = PVIN1 = PVIN2 = PVIN3 = 5V 0.1 10 μA Feedback Voltage (FB1 Pin) l 0.766 0.782 0.798 V Feedback Input Current (FB1 Pin) 1 50 nA Forward Current Limit (Note 3) LTC3520E l 1.4 2 A LTC3520I l 1.25 1.85 A Reverse Current Limit (Note 3) 560 mA Burst Mode Operation Current Limit (Note 3) 325 mA Error Amplifi er Gain 80 dB Error Amplifi er Sink Current 500 μA Error Amplifi er Source Current 14 μA Maximum Duty Cycle Boost (% Switch C is On) l 70 80 % Buck (% Switch A is On) 100 % Minimum Duty Cycle l 0 % Soft-Start Charging Current 6 μA SD1, PWM1 Input High Voltage 1.4 V SD1, PWM1 Input Low Voltage 0.4 V SD1, PWM1 Input Current 0.01 1 μA
Gain Block
Quiescent Current VAIN = 0.88V, VSD1 = VSD2 = 0V 45 μA AIN Pin Threshold Voltage l 0.770 0.786 0.802 V AIN Pin Input Bias Current 1 50 nA AOUT Sink Current VAIN = 0.72V, VAOUT = 1.8V 17 mA AOUT Source Current VAIN = 0.88V, VAOUT = 1.8V 18 μA AOUT Pin Voltage VAIN = 0.72V, IAOUT = 1mA 25 150 mV Open Loop Gain 80 dB 3520fa 3