Datasheet LTC3560 (Analog Devices) - 6

LTC3560
TYPICAL PERFORMANCE CHARACTERISTICS (From Figure 1a Except for the Resistive Divider Resistor Values) Load Step Load Step Load Step
VOUT VOUT VOUT 200mV/DIV 200mV/DIV 200mV/DIV AC COUPLED AC COUPLED AC COUPLED IL IL IL 1A/DIV 1A/DIV 1A/DIV ILOAD ILOAD ILOAD 1A/DIV 1A/DIV 1A/DIV 20μs/DIV 3560 G22 VIN = 3.6V 20μs/DIV 3560 G23 VIN = 3.6V 20μs/DIV 3560 G24 VIN = 3.6V VOUT = 1.8V VOUT = 1.8V VOUT = 1.8V ILOAD = 0A TO 800mA ILOAD = 50mA TO 800mA ILOAD = 100mA TO 800mA Burst Mode OPERATION Burst Mode OPERATION Burst Mode OPERATION
PIN FUNCTIONS RUN (Pin 1):
Run Control Input. Forcing this pin above 1.5V
VFB (Pin 5):
Feedback Pin. Receives the feedback voltage enables the part. Forcing this pin below 0.3V shuts down from an external resistive divider across the output. the device. In shutdown, all functions are disabled drawing
SYNC/MODE (Pin 6):
External Clock Synchronization and <1μA supply current. Do not leave RUN fl oating. Mode Select Input. To synchronize with an external clock,
GND (Pin 2):
Ground Pin. apply a clock with a frequency between 1MHz and 3MHz. To select pulse-skipping mode, tie to V
SW (Pin 3):
Switch Node Connection to Inductor. This pin IN. Grounding this pin selects Burst Mode operation. Do not leave this pin connects to the drains of the internal main and synchronous fl oating. power MOSFET switches.
VIN (Pin 4):
Main Supply Pin. Must be closely decoupled to GND, Pin 2, with a 10μF or greater ceramic capacitor.
FUNCTIONAL DIAGRAM
SYNC/MODE 6 SLOPE COMP OSC OSC 0.65V FREQ 4 VIN SHIFT – VFB EN + – 5 SLEEP + 0.6V – + 5Ω 0.4V + ICOMP – EA BURST S Q VIN SWITCHING R Q LOGIC RUN ANTI- RS LATCH AND SHOOT- 1 0.6V REF BLANKING 3 SW THRU CIRCUIT + SHUTDOWN IRCMP– 2 GND 3560 BD 3560fb 6