Datasheet

5
LTC34 06B
3406bfa
TYPICAL PERFOR A CE CHARACTERISTICS
UW
(From Figure 1a Except for the Resistive Divider Resistor Values)
Start-Up from Shutdown Load Step
Load Step
Load Step
Load Step
UU
U
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.
V
IN
(Pin 4): Main Supply Pin. Must be closely decoupled
to GND, Pin 2, with a 2.2µF or greater ceramic capacitor.
V
FB
(Pin 5) (LTC3406B): Feedback Pin. Receives the
feedback voltage from an external resistive divider across
the output.
V
OUT
(Pin 5) (LTC3406B-1.5/LTC3406B-1.8): Output Volt-
age Feedback Pin. An internal resistive divider divides the
output voltage down for comparison to the internal refer-
ence voltage.
RUN
5V/DIV
V
OUT
1V/DIV
I
L
500mA/DIV
40µs/DIV
V
IN
= 3.6V
V
OUT
= 1.8V
I
LOAD
= 600mA (LOAD: 3Ω RESISTOR)
3406B G16
V
OUT
100mV/DIV
AC COUPLED
I
L
500mA/DIV
I
LOAD
500mA/DIV
20µs/DIV
V
IN
= 3.6V
V
OUT
= 1.8V
I
LOAD
= 0mA TO 600mA
3406B G17
V
OUT
100mV/DIV
AC COUPLED
I
LOAD
500mA/DIV
I
L
500mA/DIV
20µs/DIV
V
IN
= 3.6V
V
OUT
= 1.8V
I
LOAD
= 50mA TO 600mA
3406B G18
V
OUT
100mV/DIV
AC COUPLED
I
L
500mA/DIV
I
LOAD
500mA/DIV
20µs/DIV
V
IN
= 3.6V
V
OUT
= 1.8V
I
LOAD
= 100mA TO 600mA
3406B G19
V
OUT
100mV/DIV
AC COUPLED
I
L
500mA/DIV
I
LOAD
500mA/DIV
20µs/DIV
V
IN
= 3.6V
V
OUT
= 1.8V
I
LOAD
= 200mA TO 600mA
3406B G20