LTC3115-2_15 Datasheet, PDF (11/42 Pages) Linear Technology – 40V, 2A Synchronous Buck-Boost DC/DC Converter

LTC3115-2
Pin Functions (DHD/FE)
PV_IN (Pin 14/Pin 17): Power Input for the Buck-Boost
Converter. A 4.7µF or larger bypass capacitor should
be connected between this pin and ground. The bypass
capacitor should be located as close to the IC as possible
and should via directly down to the ground plane. When
powered through long leads or from a high ESR power
source, a larger bulk input capacitor (typically 47µF to
100µF) may be required to stabilize the input voltage
and prevent input filter interactions which could reduce
phase margin and output current capability in boost mode
operation.
SW1 (Pin 15/Pin 18): Buck-Boost Converter Power Switch
Pin. This pin should be connected to one side of the buck-
boost inductor.
PWM/SYNC (Pin 16/Pin 19): Burst Mode/PWM Mode
Control Pin and Synchronization Input. Forcing this pin
high causes the IC to operate in fixed frequency PWM
mode at all loads using the internal oscillator at the
frequency set by the RT Pin. Forcing this pin low places
the IC into Burst Mode operation regardless of load cur-
rent. Burst Mode operation improves light load efficiency
and reduces standby current. If an external clock signal
is connected to this pin, the buck-boost converter will
synchronize its switching with the external clock using
fixed frequency PWM mode operation. The pulse width
(negative or positive) of the applied clock should be at
least 100ns. The maximum operating voltage for the
PWM/SYNC pin is 5.5V. The PWM/SYNC pin can be con-
nected to V_CC to force it high continuously.
PGND (Exposed Pad Pin 17/Pins 1, 10, 11, 20, Exposed
Pad Pin 21): Power Ground Connections. These pins
should be connected to the power ground in the applica-
tion. The exposed pad is the power ground connection. It
must be soldered to the PCB and electrically connected
to ground through the shortest and lowest impedance
connection possible and to the PCB ground plane for
rated thermal performance.
For more information www.linear.com/LTC3115-2
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