5

LTC3405

3405fa

PI FU CTIO S

RUN (Pin 1): Run Control Input. Forcing this pin above

1.5V enables the part. Forcing this pin below 0.3V shuts

down the device. In shutdown, all functions are disabled

drawing <1µA supply current. Do not leave RUN floating.

GND (Pin 2): Ground Pin.

SW (Pin 3): Switch Node Connection to Inductor. This pin

connects to the drains of the internal main and synchro-

nous power MOSFET switches.

to GND, Pin 2, with a 2.2µF or greater ceramic capacitor.

from an external resistive divider across the output.

MODE (Pin 6): Mode Select Input. To select pulse skip-

Mode operation. Do not leave this pin floating.

3405 G20

100mV/DIV

AC

COUPLED

200mA/DIV

200mA/DIV

40µs/DIV

PULSE SKIPPING MODE

100mV/DIV

AC

COUPLED

200mA/DIV

200mA/DIV

3405 G21

40µs/DIV

Burst Mode OPERATION

3405 G22

40µs/DIV

Burst Mode OPERATION

100mV/DIV

AC

COUPLED

200mA/DIV

200mA/DIV

TYPICAL PERFOR A CE CHARACTERISTICS

Load Step

Load Step

Load Step

(From Figure 1a Except for the Resistive Divider Resistor Values)