LTC3727/LTC3727-1 WUTYPICAL PERFOR A CE CHARACTERISTICSCurrent Sense Pin Input CurrentEXTVCC Switch ResistanceOscillator Frequencyvs Temperaturevs Temperaturevs Temperature 35 10 700 VOUT = 5V μA) Ω 600 V 33 8 PLLFLTR = 5V 500 31 6 VPLLFLTR = 1.2V 400 300 29 4 VPLLFLTR = 0V SWITCH RESISTANCE ( FREQUENCY (kHz) 200 CC 27 2 EXTV 100 CURRENT SENSE INPUT CURRENT ( 25 0 0 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 – 50 – 25 0 25 50 75 100 125 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) 3727 G22 3727 G23 3727 G24 Undervoltage LockoutShutdown Latch Thresholdsvs Temperaturevs Temperature 3.50 4.5 4.0 LATCH ARMING 3.45 3.5 3.40 3.0 LATCHOFF THRESHOLD 2.5 3.35 2.0 3.30 1.5 1.0 UNDERVOLTAGE LOCKOUT (V) 3.25 SHUTDOWN LATCH THRESHOLDS (V) 0.5 LTC3727 ONLY 3.20 0 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) TEMPERATURE (°C) 3727 G25 3727 G26 UUUPI FU CTIO S G Package/UH PackageRUN/SS1, RUN/SS2 (Pins 1, 15/Pins 28, 13): Combina- SENSE1+, SENSE2+ (Pins 2, 14/Pins 30, 12): The (+) tion of Soft-Start, Run Control Inputs and Short-Circuit Input to the Differential Current Comparators. The ITH pin Detection Timers (LTC3727 only). A capacitor to ground at voltage and controlled offsets between the SENSE– and each of these pins sets the ramp time to full output current. SENSE+ pins in conjunction with RSENSE set the current Forcing either of these pins back below 1.0V causes the IC trip threshold. to shut down the circuitry required for that particular SENSE1–, SENSE2– (Pins 3, 13/Pins 31, 11): The (–) controller. Latchoff overcurrent protection is also invoked Input to the Differential Current Comparators. via this pin as described in the Applications Information section (LTC3727 only). VOSENSE1, VOSENSE2 (Pins 4, 12/Pins 1, 9): Receives the remotely-sensed feedback voltage for each controller from an external resistive divider across the output. 3727fc 7