LTC3619B Typical perForMance characTerisTics TA = 25°C, VIN = 5V, unless otherwise noted.Average Input Current Limitvs TemperatureLoad Step (Channel 1)Load Step (Channel 1) 8 VIN = 5V V 6 ILIM = 475mA OUT 200mV/DIV VOUT AC-COUPLED 200mV/DIV 4 AC-COUPLED 2 I I L L 0 500mA/DIV 500mA/DIV ERROR (%) –2 I INLIM I I LOAD LOAD 500mA/DIV –4 500mA/DIV –6 20µs/DIV 3619B G20 20µs/DIV 3619B G21 VIN = 5V, VOUT = 3.3V VIN = 5V, VOUT = 1.8V –8 I I –50 LOAD = 0A TO 400mA LOAD = 40mA TO 400mA –25 0 25 50 75 100 125 CL = 4.7µF CL = 4.7µF TEMPERATURE (°C) 3619B G19 pin FuncTions (DD/MSE) VFB1 (Pin 1/Pin 1): Regulator 1 Output Feedback. Receives SW2 (Pin 7/Pin 7): Regulator 2 Switch Node Connection the feedback voltage from the external resistive divider to the Inductor. This pin swings from VIN to GND. across the regulator 1 output. Nominal voltage for this pin is 0.6V. PGOOD2 (Pin 8/Pin 8): Open-Drain Logic Output. PGOOD2 is pulled to ground if the voltage on the VFB2 pin is not RUN1 (Pin 2/Pin 2): Regulator 1 Enable. Forcing this pin within power good threshold. to VIN enables regulator 1, while forcing it to GND causes regulator 1 to shut down. RUN2 (Pin 9/Pin 9): Regulator 2 Enable. Forcing this pin to VIN enables regulator 2, while forcing it to GND causes RLIM (Pin 3/Pin 3): Average Input Current Limit Program regulator 2 to shut down. Pin. Place a resistor and capacitor in parallel from this pin to ground. VFB2 (Pin 10/Pin 10): Regulator 2 Output Feedback. Receives the feedback voltage from the external resistive PGOOD1 (Pin 4/Pin 4): Open-Drain Logic Output. PGOOD1 divider across the regulator 2 output. Nominal voltage for is pulled to ground if the voltage on the VFB1 pin is not this pin is 0.6V. within power good threshold. GND (Pin 11/Pin 11): Ground. Bottom Exposed Pad. Con- SW1 (Pin 5/Pin 5): Regulator 1 Switch Node Connection nect to the (–) terminal of C to the Inductor. This pin swings from V OUT, and the (–) terminal of IN to GND. CIN. The Exposed Pad must be soldered to PCB. VIN (Pin 6/Pin 6): Main Power Supply. Must be closely de-coupled to GND. 3619bfb 6 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Package Description Revision History Typical Applications Related Parts