LTC3412
PI FU CTIO S
SV
IN
(Pin 1/Pin 11):
Signal Input Supply. Decouple this
pin to SGND with a capacitor. Normally SV
IN
is equal to
PV
IN
. SV
IN
can be greater than PV
IN
but keep the voltage
difference between SV
IN
and PV
IN
less than 0.5V.
PGOOD (Pin 2/Pin 12):
Power Good Output. Open-drain
logic output that is pulled to ground when the output
voltage is not within
±7.5%
of regulation point.
I
TH
(Pin 3/Pin 13):
Error Amplifier Compensation Point.
The current comparator threshold increases with this
control voltage. Nominal voltage range for this pin is from
0.2V to 1.4V with 0.2V corresponding to the zero-sense
voltage (zero current).
V
FB
(Pin 4/Pin 14):
Feedback Pin. Receives the feedback
voltage from a resistive divider connected across the
output.
R
T
(Pin 5/Pin 15):
Oscillator Resistor Input. Connecting a
resistor to ground from this pin sets the switching fre-
quency.
SYNC/MODE (Pin 6/Pin 16):
Mode Select and External
Clock Synchronization Input. To select forced continuous,
tie to SV
IN
. Connecting this pin to a voltage between 0V and
1V selects Burst Mode operation with the burst clamp set
to the pin voltage.
6
U
U
U
(FE/UH Package)
RUN/SS (Pin 7/Pin 1):
Run Control and Soft-Start Input.
Forcing this pin below 0.5V shuts down the LTC3412. In
shutdown all functions are disabled drawing < 1μA of
supply current. A capacitor to ground from this pin sets the
ramp time to full output current.
SGND (Pin 8/Pin 2):
Signal Ground. All small-signal
components, compensation components and the exposed
pad on the bottom side of the IC should connect to this
ground, which in turn connects to PGND at one point.
PV
IN
(Pins 9, 16/Pins 3, 10):
Power Input Supply. Decouple
this pin to PGND with a capacitor.
SW (Pins 10, 11, 14, 15/Pins 4, 5, 8, 9):
Switch Node
Connection to the Inductor. This pin connects to the drains
of the internal main and synchronous power MOSFET
switches.
PGND (Pins 12, 13/Pins 6, 7):
Power Ground. Connect
this pin close to the (–) terminal of C
IN
and C
OUT
.
Exposed Pad (Pin 17/Pin 17):
Signal Ground. Must be
soldered to PCB for electrical connection and thermal
performance.
3412fb
LINER [ LINEAR TECHNOLOGY ]
