LTC3404IMS8 Datasheet, PDF (6/16 Pages) Linear Technology – 1.4MHz High Efficiency Monolithic Synchronous Step-Down Regulator

LTC3404
TYPICAL PERFOR A CE CHARACTERISTICS
Load Step Response
Load Step Response
Load Step Response
V_OUT
100mV/DIV
I_L
500mA/DIV
V_OUT
100mV/DIV
I_L
500mA/DIV
V_OUT
100mV/DIV
I_L
500mA/DIV
I_TH
1V/DIV
V_IN = 3.6V
V_OUT = 1.5V
L = 4.7μH
40μs/DIV
C_IN = 10μF
C_OUT = 22μF
I_LOAD = 200mA TO 500mA 3404 G17
PULSE SKIPPING MODE
I_TH
1V/DIV
V_IN = 3.6V
V_OUT = 1.5V
L = 4.7μH
40μs/DIV
C_IN = 10μF
C_OUT = 22μF
I_LOAD = 50mA TO 500mA
PULSE SKIPPING MODE
3404 G18
I_TH
1V/DIV
V_IN = 3.6V
V_OUT = 1.5V
L = 4.7μH
40μs/DIV
C_IN = 10μF
C_OUT = 22μF
I_LOAD = 50mA TO 500mA
Burst Mode OPERATION
3404 G19
PI FU CTIO S
RUN (Pin 1): Run Control Input. Forcing this pin below
0.4V shuts down the LTC3404. In shutdown all functions
are disabled drawing < 1μA supply current. Forcing this
pin above 1.2V enables the LTC3404. Do not leave RUN
floating.
I_TH (Pin 2): Error Amplifier Compensation Point. The
current comparator threshold increases with this control
voltage. Nominal voltage range for this pin is from 0.5V
to 1.9V.
V_FB (Pin 3): Feedback Pin. Receives the feedback voltage
from an external resistive divider across the output.
GND (Pin 4): Ground Pin.
SW (Pin 5): Switch Node Connection to Inductor. This pin
connects to the drains of the internal main and synchro-
nous power MOSFET switches.
V_IN (Pin 6): Main Supply Pin. Must be closely decoupled
to GND, Pin 4.
SYNC/MODE (Pin 7): External Clock Synchronization and
Mode Select Input. To synchronize with an external clock,
apply a clock with a frequency between 1MHz and 1.7MHz.
To select Burst Mode operation, tie to V_IN. Grounding this
pin selects pulse skipping mode. Do not leave this pin
floating.
PLL LPF (Pin 8): Output of the Phase Detector and Control
Input of Oscillator. Connect a series RC lowpass network
from this pin to ground if externally synchronized. If
unused, this pin may be left open.
3404fb
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